Dissertations / Theses: 'Other Earth Sciences'

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Alvarez, Pedro Felix. "Lattice boltzmann modeling of fluid flow to determine the permeability of a karst specimen." FIU Digital Commons, 2007. http://digitalcommons.fiu.edu/etd/1270.

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A limestone sample was scanned using computed tomography (CT) and the hydraulic conductivity of the 3D reconstructed sample was determined using Lattice- Boltzmann methods (LBM) at varying scales. Due to the shape and size of the original sample, it was challenging to obtain a consistent rectilinear test sample. Through visual inspection however, 91 mm and 76 mm samples were digitally cut from the original. The samples had porosities of 58% and 64% and produced hydraulic conductivity values of K= 13.5 m/s and K=34.5 m/s, respectively. Both of these samples were re-sampled to 1/8 and 1/64 of their original size to produce new virtual samples at lower resolutions of 0.542 mm/lu and 1.084 mm/lu, while still representing the same physical dimensions. The hydraulic conductivity tended to increase slightly as the resolution became coarser. In order to determine an REV, the 91 mm sample was also sub-sampled into blocks that were 1/8 and 1/64 the size of the original. The results were consistent with analytical expectations such as those produced by the Kozeny-Carman equation. A definitive REV size was not reached, however, indicating the need for a larger sample. The methods described here demonstrate the ability of LBM to test rock structures and sizes not normally attainable.

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Subedi, Suresh Chandra. "A Functional Trait Approach to Examine Plant Community Dynamics in South Florida Hardwood Hammock Forests." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3373.

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The tropical hardwood forests of south Florida persist as well-drained patches of broadleaf forest separated by brackish water swamp, marsh, or pineland. In this dissertation, a functional trait approach was used to understand the structure and dynamics of these communities and their responses to abiotic and biotic variation. Twenty-seven permanent plots (20 x 20 m2) were established across the south Florida landscape, representing four sub-regions: Everglades marsh, Long Pine Key, Upper Keys, and Lower Keys. Community weighted mean trait values for four of six selected traits showed significant inter-sub-regional variation. Out of them, three traits (specific leaf area, tree height, and leaf phosphorus) increased significantly from dry and low productivity Florida Keys in the south to the moist and productive areas on the south Florida mainland, while wood density showed the opposite pattern. Trait variance ratios (T-statistic metrics) was used to explore internal filtering (processes that operate within a community) and external filtering (processes that operate at larger scale than that of the individual population or community) on community structure. Both external and internal filtering in the functional composition of south Florida hardwood hammock forest were important for local communities differing in freshwater accessibility, or that occupy different positions along strong edaphic or climatic gradients. To understand the underlying mechanisms that drive species assembly during forest succession in Florida dry sub-tropical forest, 13 leaf, stem, reproductive, and architectural traits of resident tree species across the successional gradient were measured. Tests of null models showed that younger communities are shaped by environmentally driven processes, while mature communities are shaped by competitively driven processes. The overall trait similarities among species present in North Key Largo tropical dry forest suggest that tree species are specialists on the local environment, and their ability to survive and grow in a stressful environment may be more important than competition for resources at larger scale. Moreover, tree species in these forests may exhibit specialization or trait plasticity in coping with drought by changes in their stomatal morphology or activity, allowing for a balance between gas exchange and water loss in a periodically stressful environment. A significant negative correlation between stomatal density and size, and a positive correlation between leaf δ13C and stomatal density were observed across habitat gradient for one of the dominant hardwood hammock species (Bursera simaruba). Small and densely distributed stomates in tandem seems to represent a strategy that allows hammock species to conserve water under physiological drought. Furthermore, findings from this work also showed both intra- and inter-specific trait variation at regional and local scales influence community assembly patterns in hardwood hammock communities in South Florida.

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Gross, Howard P. "Evaluation of Lake Fertilization as a Tool to Assist in the Recovery of the Snake River Sockeye Salmon (Oncorhynchus Nerka)." DigitalCommons@USU, 1995. https://digitalcommons.usu.edu/etd/6972.

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I analyzed lake fertilization (with nitrogen and phosphorus) as a tool to assist in the recovery of the Snake River sockeye salmon (Oncorhynchus ~) in the oligotrophic Sawtooth Valley Lakes in southcentral Idaho. These analyses involved monitoring, manipulating, and modelling several aspects of the lakes' primary producer, nutrient, and light parameters. In Pettit Lake, I evaluated the effects of metalimnetic and epilimnetic fertilization in 330-m 3 mesocosms. The metalimnetic treatment was equal to or more effective than the epilimnetic treatment in increasing chlorophyll a, phytoplankton biovolume, and primary productivity, yet caused smaller changes in periphyton growth and water clarity. Thus, metalirnnetic fertilization may provide a tool for increasing lake productivity while minimally impacting water clarity. The Sawtooth Valley Lakes had deep chlorophyll maxima (DCM) with mean chlorophyll a peaks 240-1000% of mean epilimnetic concentrations. The DCM existed at low light levels and accounted for 36- 72% of the lakes' primary production. Epilimnetic fertilization of330-m 3 mesocosms in Redfish Lake increased levels of primary productivity and chlorophyll a, but decreased Secchi depths and light available in the meta- and hypolimnion. I modelled the effects of increased chlorophyll (resulting from epilimnetic fertilization) and decreased light penetration on vertical primary productivity profiles. The simulations showed a large increase in epilimnetic primary productivity due to fertilization, and only a slight decrease in production in the deeper strata due to self-shading. I also modelled the dependence of Red fish Lake's production on nutrients from the watershed, from lake fertilization, and from marine-derived nutrients from salmon. The model utilized our water budget and nutrient loading measurements. The model and empirical evidence indicated that even before hydropower dams were present in the migration corridor, marine-derived nutrients were not of major importance to lake production, contributing only ~3% of the lake's annual phosphorus load. This contribution was partially offset by the lake's quick flushing rate (3 yr) and phosphorus export by smolts. The model predicted annual adult salmon returns to be 3,800 under pre-dam conditions, 370 under modern conditions, 750 when doubling watershed nutrient loading (simulating lake fertilization), and 780 when doubling migration survival.

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Mongillo, M. A. (Mike A. ). 1949. "Remote sensing techniques for geothermal investigation and monitoring in New Zealand." Thesis, University of Auckland, 1992. http://hdl.handle.net/2292/2141.

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This thesis examines the use of remote sensing techniques for the investigation and monitoring of geothermal areas in the Taupo volcanic zone of New Zealand. The research and development of a helicopter-borne video thermal infrared scanner technique and associated computer image processing methods constitutes the major portion of this study. In addition, preliminary results are presented from a related shallow ground temperature study conducted to investigate diurnal, seasonal and meteorological effects on temperatures in active thermal ground and results from a precursory assessment of SPOT-l satellite multispectral imagery obtained over the Waiotapu Geothermal Field for detecting, identifying and mapping characteristic geothermal surface features are also reported. The initial conduct of two video thermal IR scanner test surveys, one using an Inframetrics 525 over portions of the Rotorua Geothermal Field, the other using a FLIR 1000A over portions of the Wairakei-Tauhara Geothermal Field, demonstrated that imagery useful for basic geothermal feature mapping could be obtained in the late summer to early autumn period. Surveying during the hours around dusk was shown to be appropriate. Experimentation established instrument operating settings and defined nominal survey parameters. The real-time video imagery format proved useful as an aid to navigation and as a check on proper instrument set-up and operation- The helicopter platform provided valuable manoeuvrability and control. The results obtained from these two initial surveys aided development of survey design and conduct methodology. The video imagery obtained with both the Inframetrics and FLIR scanners was compatible with New Zealand's PAL standard- Visual TV-VCR inspection of the IR imagery allowed easy identification of a range of natural thermal features. Identification of cultural features aided location of the thermal anomalies. The Inframetrics imagery suffered from serious banding and other minor problems. The FLIR imagery was of a generally higher quality, though it exhibited problems. The fundamental ability to digitize images from the videotapes and apply powerful computer image processing techniques to aid interpretation and analysis was demonstrated. A methodology for pre-processing and enhancing the digitized Inframetrics and FLIR images was developed. Application of these image processing techniques brought out detail unavailable in the grey-level imagery and greatly increased interpretation ability. The demonstrated success of the first two test surveys led to the conduct of the first known large-scale video thermal IR scanner surveys of geothermal fields. Most details of the first of these ate confidential (at the client's request). A complete range of geothermal features was detected and easily recognised and their distribution established thus providing a much more detailed map of the geothermal activity than was previously available. The successful results attained confirmed the survey design and conduct methodology used. The second and largest survey covered the entire Rotorua Geothermal Field (l8 km2). Imagery was obtained with both the Inframetrics and FLIR IR scanners and a visible wavelength video camera. Extensive ground control measurements were made. This comprehensive survey of geothermal activity established a baseline from which change can be monitored The survey identified large scale seepage and submerged thermal input into Lake Rotorua which may be the source of known missing chloride. The first geothermal surface feature changes were identified, thus demonstrating the usefulness of the method for monitoring change. Preliminary image temperature calibration results were obtained and a procedure for constructing visible wavelength-thermal IR composite images was developed. The positive results demonstrated by this survey have led to the helicopter-borne video thermal IR technique being adopted for major geothermal feature mapping and monitoring programmes in New Zealand. Preliminary assessment of the high spatial resolution (20m) SPOT-1 multispectral imagery of the Waiotapu Geothermal Field. showed that the larger geothermal surface features can be detected and identified on a contrast stretched, 3-band colour composite image. A shallow (≤ 1m depth) ground temperature measurement site was established in an area extending from very active to near ambient conditions. Preliminary results show that temperature variations ranging from l-19 °C can occur in the most active ground. These temperature variations exhibit a strong negative correlation with atmospheric prcss111e changes and can introduce large, unexpected inaccuracies in ground temperature measurements.

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Herald, John R. (John Raymond). "Hydrological impacts of urban development in the Albany Basin, Auckland." Thesis, University of Auckland, 1989. http://hdl.handle.net/2292/2278.

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In several areas of Auckland, urban development has resulted in flooding and siltation problems that have been both difficult and expensive to manage. This study investigates the fluvial processes of runoff and sediment generation with a pastoral catchment of the Albany Basin and assesses the potential hydrological impacts of urban development with its catchment area. During the study period this catchment was on the fringe of the urban development of Auckland's North Shore. By examining the factors that control runoff and sediment generation within a pastoral catchment, site information that may be useful for controlling runoff and sediment generation within an urbanised Albany Basin is gained. To assess the impacts of urban development, streamflows and suspended sediment yields from catchments representative of three different land uses are compared: pastoral, urban construction and developed urban. Stream channel enlargement indices for a number of nearby catchments with different proportions of urban land cover are also determined and compared. The study shows significant increases in stormflows and suspended sediment yields from catchments that are either fully developed or undergoing construction for urban use. But due to the relatively dry weather experienced during the study period these results are thought to underestimate the impact of urbanising the Albany Basin. The investigation of stream channel enlargement shows that for totally urban catchments stream channel cross-sectional areas may be nearly three times those for pastoral catchments. Methods for controlling the impact of urban development on streamflows, sediment yields and channel enlargement are discussed. It is proposed that by developing techniques where by storm runoff is dispersed and stored within the considerable soil moisture storage capacity of an urban land cover, of the type planned for the Albany Basin, that a considerable reduction in stormflow and sediment generation may be achieved. The study concludes that through careful land use planning and the use of appropriate control structure the impacts of urban development may be reduced to acceptable levels.

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Hilton, Michael John. "Processes of sedimentation on the shoreface and continental shelf and the development of facies Pakiri, New Zealand." Thesis, University of Auckland, 1990. http://hdl.handle.net/2292/2294.

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This dissertation presents the results of research of physical and biological processes of sedimentation on the shoreface and continental shelf in Pakiri Bay, on the east coast of the Northland Peninsu1a, New Zealand. These environments comprise the subtidal portion of the Pakiri sand body. Sand bodies that are contiguous with unconsolidated sediments of coastal barriers are characteristic of the embayed east coasts of the Auckland and Northland Regions, yet little is known of their geomorphology. Existing models of shoreface and shelf sedimentation afford limited assistance because they were developed in different environments. Factors that distinguish the study area from other coasts include tectonic stability, lack of modern (non-biogenic) sediment inputs, the predominance of currents related to shoaling surface waves, and a sea level stillstand for the last 6,500 years. The model of sedimentation developed is derived from intensive field investigation of the morphology, sedimentology and ecology of the Pakiri Bay shoreface and continental shelf. Investigations of sediment transport entail interpretations of the sediments and sedimentary structures of the seabed, application of existing sediment transport models and the analysis of morphodynamic data. The geomorphology of the Pakiri sediment body is characterized by a regular pattern of morphologic components and associated sediment types. Alongshore variation in these characteristics is generally minor compared with shore normal variation. The shoreface comprises a curvilinear concave surface, that extends offshore from the alongshore bar approximately 1500 m, to water depths of about 22 n. The inner continental shelf comprises an equally curvilinear, mostly convex, surface that slopes seaward to the relatively flat middle continental shelf. Secondary morphological variations result from the presence of large-scale bedforms on the middle continental shelf and landward margin of the inner shelf. The sediments of the shoreface are fine, very well sorted quartz-feldspathic sands of 2 ø mean grain size. The inner shelf sediments grade offshore from a medium sand to very coarse sands and fine gravels (mean grain size 0.0 to 0.5 ø). In contrast the sediments of the mid shelf are very fine sands (mean grain size 2.0 to 2.5 ø), with a mud content of 5 to l0 percent. Carbonate skeletal debris, derived mostly from molluscs, comprises a significant proportion of inner and mid shelf sediments. The concentration of carbonates in the sediments increases offshore from 0 to 5 percent on the shoreface to 30 percent at the base of the inner shelf. The carbonate fraction of the sediments is size graded on the inner shelf and mid shelf in accordance with the grain size characteristics of the non-carbonate fraction. A model of the distribution and abundance of living macrobenthos (mostly of the phyla mollusca) is derived from benthos surveys in Pakiri Bay. Species that are diagnostic of high and low energy environments are characteristic of the shoreface and middle continental shelf respectively. The pattern of carbonate concentration in the sediments of the subtidal sediment body does not correlate with the pattern of modern biogenic production. Highest levels of modern shell production occur across the shoreface, whereas carbonate concentrations are greatest at the base of the inner shelf. Hypotheses are advanced to explain this dichotomy. The geomorphology of the shoreface and inner continental shelf is seen as a response to modern processes of sedimentation. Sediment transport occurs primarily in response to currents related to shoaling waves. Two process regimes are recognized. During typically calm (swe11 wave) conditions the fine sands of the shoreface may be transported landward as a result of an onshore mass transport current. During severe storm events this process may transport bed sediments landward across the inner shelf and middle continental shelf forming the characteristic sediment and morphologic patterns observed. However, during such events this onshore flow is, probably counteracted by return flows that are able to transport eroded foreshore and inshore sediments seaward Key words: Sedimentation, shoreface, continental shelf, wave dominated, carbonated sedimentation, sediment body, facies.

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Sem, Graham. "The soil seed bank in Agathis australis (D. Don) Lindl. (kauri) forests of northern New Zealand and its potential role in secondary successions." Thesis, University of Auckland, 1991. http://hdl.handle.net/2292/2307.

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The soil seed bank in Agathis australis (D. Don) Lindl. (kauri) forests of northern New Zealand is quantified, and its potential role in secondary successions examined. Seed bank data from a number of kauri forest sites stratified by successional time and distance from forest edges are summarized using Detrended Correspondence Analysis (ordination) and linear regression models. A number of issues concerning secondary successions and the soil seed bank are discussed. These include: 1. The relationship between the soil seed bank and extant vegetation. 2. The nature of the soil seed bank and successional time. 3. The nature of the soil seed bank and distance from forest edges. 4. The soil seed bank, canopy gaps and gap regeneration strategies. 5. The nature of the soil seed bank and soil properties. 6. The fruiting phenology, seed rain, and soil seed bank dynamics. The forest sites ranged from 50 years to over 1,000 years old, while distance from forest edges ranged from 0.2 km to 3.5 km. Soil seed bank densities under kauri forests were 134 - 5,388 seeds m-2 with a mean density of 1,320±217 seeds m-2 which is similar to estimates reported for temperate and tropical forest sites elsewhere. The spatial distribution of seeds in the seed bank both within and between sites is highly variable. A total of 6,062 seedlings emerged from the seed bank samples. This represented 62 vascular plant species, 26 (42%) native woody, 19 (30%) native weedy, 16 (26) adventive weedy and 1 (2%) native fern. The species composition of the soil seed bank was not closely related to extant vegetation and only 11%ot canopy and 13% of understorey species were represented in the soil seed bank. Thus, 77% of extant vegetation at any given site is floristically different from that of the soil seed bank. Ordination of the data by detrended correspondence analysis (DCA) suggested that extant vegetation (canopy and understorey) and the soil seed bank contain characteristic floras. The species composition of the seed bank is variable between sites. The viable seed pool is larger under young successional forests than under older mature forests. The number of species also declined with distance from forest edges. Adventive and native weedy species were found in seed banks under mature forests and sites of considerable distances from forest edges. However, the density of the weedy species component of the soil seed bank was at least partly determined by distance from forest edges where such species are common. While buried seed is likely to contribute to the early stages of secondary succession, evidence from canopy gaps suggested that the seedling bank (formerly suppressed understorey component) is more important in gap regeneration than the soil seed bank. DCA analysis revealed that seedling bank species composition of canopy gaps and forest sites were quite different from the soil seed banks, indicating that regeneration stemmed from formerly (suppressed) understorey seedlings. Phenology and seed rain study of a mature forest remnant and a regenerating forest community showed that as little as 5% of the seed input to the forest floor enters the soil seed bank and remains viable for more than one year. Evidence is presented to suggest that in a forest community, secondary succession after large-scale or localised disturbance, is achieved more so by suppressed seedlings and recent seed rain than the soil seed bank. The soil seed bank becomes significant in secondary succession when the subsoil is disturbed by the uprooting of trees or the forest floor is exposed by tree-fall (not covered by tree-fall debris).

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Shitima, Mwepya Ephraim. "Forest Conservation and People’s Livelihoods: Explaining Encroachment on Zambia’s Protected Forest Landscapes - The Case Of Mwekera National Forest, Kitwe, Copperbelt." Thesis, Norwegian University of Science and Technology, Faculty of Social Sciences and Technology Management, 2005. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-571.

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Forest Conservation and People’s Livelihoods: Explaining Encroachment on Zambia’s Protected Forest Landscapes - The Case Of Mwekera National Forest, Kitwe, Copperbelt

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The conflicts between conservation objectives and the livelihood needs of local communities are intricate and difficult to resolve and yet the success of any conservation effort hinges on their solution. This is particularly true in forest conservation in Third World countries like Zambia, where rural populations depend directly on forest resources, which are in many cases protected.

Forest reserves in Zambia have undergone drastic changes over the years due to encroachment by such human activities as agriculture, charcoal burning and even settlements. This has led to the deforestation of most of them including Mwekera National Forest in Kitwe on the Copperbelt province. The Forest Department has attempted to involve the people in the management of these resources in a bid to redress the trend. But the fundamental causes for the encroachment and deforestation are not clear. This study was focused on unearthing the underlying causes of encroachment and the subsequent deforestation of Mwekera National Forest. This was done through a qualitative ethnographic approach employing individual interviews, focused group discussions, observations and pictures of relevant phenomena. The target groups included the forest communities living in and around Mwekera National Forest as well as government forestry officials at both local and national levels. The study was based on nature-culture theory, knowledge systems theory as well as the participatory approach.

The study reveals that macro-economic policies such as privatisation of the mines has undermined people’s livelihoods while the inefficient and bureaucratic land delivery system made “vacant” protected forest land an attractive option. The policy contradictions between the forest sector and other sectors such as energy, agriculture and land have not helped matters. Organisational constraints on the Forest Department such as its inadequate human, financial and other resources coupled with the delay in its transformation to a more autonomous Forest Commission have not secured protected forests. Its old centralist management approach has made participation by local people difficult to effect despite being provided for under new forestry policy and law. This has meant that decisions made by officials lack meaningful involvement and support of the local people, thereby seriously hindering effective forest protection. Herein lies one major cause of encroachment.

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Aganyira, Kellen. "Aquaculture: A Tool for Sustainable Development in Uganda. : A Case Study of Kigoowa Catholic Women’s Association in Kampala District." Thesis, Norwegian University of Science and Technology, Faculty of Social Sciences and Technology Management, 2005. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-572.

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Global aquaculture production has grown rapidly and is now among the fastest growing food production sectors in many countries.Introduced over the past 50 years or so,aquaculture in Africa has gone through different levels of growth. The desirability of aquaculture has been due to unreliable and unsustainable use of natural waters for capture fisheries. Due to the country’s concern, the government of Uganda has promoted aquaculture before for nutritional values. However, current policy initiatives that call for collective actions are geared towards commercial aquaculture development.

This work focuses on several aspects of aquaculture development in Uganda viz; past,present and future, potential, reared fish species, benefits, constraints and these are reflected in the policy and institutional arrangements with in the sector. This work has been undertaken with the aim of providing in detail the possible ways and means for sustainable utilization of aquaculture outcomes. Emphasis has been on how members of Kigoowa Catholic Women’s Development Association (KCWDA) have been empowered through group formation and aquaculture activities.

This work also analyses the dynamic gender relations that exist in resource ownership, access and use in Uganda and the implications thereof to aquaculture growth and expansion. Included are the possible options vulnerable people especially women undertake to sustain their livelihoods and those of their families and the community as a whole.

The information in this work is discussed in line with the Sustainable Livelihoods Framework. It therefore aims at providing an additional reference text on the subject and in the context of aquaculture. Details about certain concepts, policies and principles, nature of the sector and supportive literature on various issues are discussed.

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Sanches, Ieda Del'Arco. "Hyperspectral proximal sensing of the botanical composition and nutrient content of New Zealand pastures : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Earth Science." Massey University, 2009. http://hdl.handle.net/10179/1194.

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The potential of hyperspectral proximal sensing to quantify sward characteristics important in making critical decisions on the management of sheep and dairy pastures in New Zealand has been investigated. Hyperspectral data were acquired using an ASD FieldSpec® Pro FR spectroradiometer attached to the Canopy Pasture Probe (CAPP). The CAPP was developed to enable the collection of in situ reflectance data from New Zealand pasture canopies independent of ambient light conditions. A matt white ceramic tile was selected as a reflectance standard to be used with the CAPP, after testing a variety of materials. Pasture reflectance factor spectra between 350-2500 nm (with spectral resolutions of 3 nm between 350-1000 nm and 10 nm between 1000-2500 nm) and pasture samples were collected from six hill country and lowland areas, across all seasons (August 2006 to September 2007) in a number of regions in the North Island of New Zealand. After pre-processing (e.g. spectral averaging, de-stepping, elimination of noisy wavelengths, smoothing) the spectral data collected from sites were correlated against pasture botanical composition (expressed as proportions of grass, legume and weed) and pasture nutrients (nitrogen, phosphorus, potassium, calcium, magnesium, sodium and sulphur) expressed in percentage of dry matter (%) and amount (kg ha-1) using partial least squares regressions (PLSR). The accuracy and precision of the calibrations were tested using either the full cross-validation leave-one-out method or testing datasets. Regressions were carried out using the reflectance factor data per se and after mathematical transformation, including first derivative, absorbance and continuum-removed spectra. Overall best results were obtained using the first derivative data. The quality of predictions varied greatly with the pasture attribute, site and season. Some reasonable results were achieved for the prediction of pasture grass and legume proportions when analysing samples collected during autumn (grass: R2 > 0.81 and SD/RMSEP 2.3 and legume: R2 > 0.80 and SD/RMSEP 2.2), but predicting pasture weed content was poor for all sites and seasons (R2 = 0.44 and SD/RMSEP = 1.2). The inaccurate predictions might be explained by the fact that the diversity found in the field and observed in the pasture spectral data was not taken into account in the pasture botanical separation. The potential for using proximal sensing techniques to predict pasture nutrients in situ was confirmed, with the sensing of pasture N, P and K increased by the procedure of separating the data according to the season of the year. The full potential of the technology will only be realised if a substantial dataset representing all the variability found in the field is gathered. The importance of obtaining representative datasets that embrace all the biophysical factors (e.g. pasture type, canopy structure) likely to affect the relat ionship, when building prediction calibrations, was highlighted in this research by the variance in the predictions for the same nutrient using different datasets, and by the inconsistency in the number of common wavelengths when examining the wavelengths contributing to the relationship. The ability to use a single model to predict multiple nutrients, or indeed individual nutrients, will only come through a good understanding of the factors likely to influence any calibration function. It has been demonstrated in this research that reasonably accurate and precise pasture nutrient predictions (R2 > 0.74 and SD/RMSEP 2.0) can be made from fresh in situ canopy measurements. This still falls short of the quality of the predictions reported for near infrared reflectance spectroscopy (NIRS) for dried, ground samples analysed under controlled laboratory conditions

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Richardson, Jacob Armstrong. "Modeling the Construction and Evolution of Distributed Volcanic Fields on Earth and Mars." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6136.

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Magmatism is a dominant process on Earth and Mars that has significantly modified and evolved the lithospheres of each planet by delivering magma to shallow depths and to the surface. Two common modes of volcanism are present on both Earth and Mars: central-vent dominated volcanism that creates large edifices from concentrating magma in chambers before eruptions and distributed volcanism that creates many smaller edifices on the surface through the independent ascent of individual magmatic dikes. In regions of distributed volcanism, clusters of volcanoes develop over thousands to millions of years. This dissertation explores the geology of distributed volcanism on Earth and Mars from shallow depths (~1 km) to the surface. On long time scales, distributed volcanism emplaces magmatic sills below the surface and feeds volcanoes at the surface. The change in spatial distribution and formation rate of volcanoes over time is used to infer the evolution of the source region of magma generation. At short time scales, the emplacement of lava flows in these fields present an urgent hazard for nearby people and infrastructure. I present software that can be used to simulate lava flow inundation and show that individual computer codes can be validated using real-world flows. On Mars, distributed volcanism occurs in the Tharsis Volcanic Province, sometimes associated with larger, central-vent shield volcanoes. Two volcanic fields in this province are mapped here. The Syria Planum field is composed three major volcanic units, two of which are clusters of 10s to >100 shield volcanoes. This area had volcanic activity that spanned 900 million years, from 3.5-2.6 Ga. The Arsia Mons Caldera field is associated with a large shield volcano. Using crater age-dating and mapping stratigraphy between lava flows, activity in this field peaked at ~150 Ma and monotonically waned until 10-90 Ma, when volcanism likely ceased.

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Land, Timothy. "FM Radio Signal Propagation Evaluation and Creating Statistical Models for Signal Strength Prediction in Differing Topographic Environments." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etd/3423.

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Radio wave signal strength and associated propagation models are rarely analyzed across individual geographic provinces. This study evaluates the effectiveness of the Radio Mobile model to predict radio wave signal strength in the Blue Ridge and Valley and Ridge physiographic provinces. A spectrum analyzer was used on 19 FM transmitters to determine model accuracy. Statistical analysis determined the significance between different terrain factors and signal strength. Field signal strength was found to be related to test site elevation, transmitter azimuth, elevation angle, transmitter elevation, path loss, and distance. Using 76 signal strength receiver sites, Ordinary Least Square regression models predicted signal strength with 60% of variability explained in the Valley and Ridge province model and 43% of variability explained in the Blue Ridge province model. Region-specific statistical models were more accurate in determining a region’s transmitter placement and level of power for broadcasting compared to generic computer models.

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BALTZINGER, Christophe. "Sélection des sites de repos par le Cerf (Cervus elaphus L.) et le Chevreuil (Capreolus capreolus L.) vivant en sympatrie en forêt tempérée de moyenne montagne." Phd thesis, ENGREF (AgroParisTech), 2003. http://tel.archives-ouvertes.fr/tel-00005727.

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Le Cerf (Cervus elaphus) et le Chevreuil (Capreolus capreolus) sont 2 cervidés qui abondent en Europe, ils partagent souvent le même habitat. Les cervidés passent en moyenne 50% de leur temps au repos, cependant les critères de sélection des sites de repos ont été peu étudiés.
L'objectif de notre travail est double : i) décrire les patrons de sélection des sites de repos, pour chaque espèce et à différentes échelles spatiales et temporelle, et ii) comparer les patrons de sélection des deux espèces.
L'étude a été menée au sein du Parc National des Cévennes, dans la Forêt Domaniale du Bougès. L'échantillonnage par transects a permis de décrire les caractéristiques de 425 reposées, au cours de 2 hivers et de 2 étés. La méthode PCR appliquée à l'ADN de poils prélevés sur les reposées s'est révélée pertinente pour distinguer Cerf et Chevreuil.
A l'échelle du peuplement forestier, nous montrons un fort chevauchement entre Cerf et Chevreuil dans l'utilisation, pour se reposer, des différents types de peuplement. Les 2 cervidés ont tendance à éviter les peuplements résineux adultes été comme hiver. Le Chevreuil est moins sélectif à cette échelle, et utilise indifféremment les peuplements forestiers en été. Le Cerf a par contre un comportement très sélectif et manifeste une préférence marquée pour les jeunes peuplements résineux.
A l'échelle du microhabitat, le Cerf et le Chevreuil recherchent toujours une bonne protection visuelle, à travers un couvert latéral important. Ce couvert est essentiellement composé de résineux pour le Cerf, alors que le Chevreuil utilise aussi les feuillus quand ils sont disponibles en été.
En hiver, le Chevreuil se couche sous un fort couvert dans la canopée, ce couvert est plus élevé que pour le Cerf. Il se repose à proximité des lisières contrairement au Cerf qui sen éloigne.
Nous discutons ces différences de patron de sélection entre le Cerf, qui occupe un domaine vital étendu, et le Chevreuil, territorial, qui vit sur un domaine beaucoup plus restreint.

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Thomason, Rachelle. "Biloxi Marsh Platform Response due to Meteorological Forcing." ScholarWorks@UNO, 2016. http://scholarworks.uno.edu/td/2280.

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The Biloxi Marsh of the eastern Mississippi River delta plain is exposed to meteorological forces ranging from large-scale, mid-latitude cyclones to smaller scale storms and squalls. Each time that these marsh platforms are exposed to a storm event, the potential exists for either deposition or erosion to take place. This study examines the connection between wind speeds, stratigraphic composition, marsh edge morphology, and marsh edge erosion at 4 sites in the Biloxi Marsh. As much as 2.17 m of erosion were measured during the 9-month study with a maximum, averaged erosion rate of 0.03 m day-1. Shell berm transgression was also documented as the result of winds from a low-pressure system near the site that resulted large waves. Shell berm movement occurred as a result of high wind speeds on shore but there was no connection between wind speeds and erosion for the duration of this study across all sites.

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15

Hutton, Mark. "Only the Earth Remains: Exploring the Machine in Selected Lyric Poetry of Robinson Jeffers." Digital Commons @ East Tennessee State University, 2017. https://dc.etsu.edu/etd/3322.

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In The Machine in the Garden: Technology and the Pastoral Idea in America, Leo Marx “evaluates the uses of the pastoral ideal in the interpretation of American experience” (Marx 4). While Marx explores ways that pastoralism has been impacted by factors such as industrialism, it is the purpose of this project to explore Marx’s assertion regarding the presence of the figurative and literal machine within the poetry of Robinson Jeffers. Jeffers’ poetry is generally located within the landscapes of California. His lyric poetry has a distinct connection to the land and is driven by inhumanism, which works to shift the “emphasis and significance from man to not-man…” (Oelschlaeger 246). Jeffers’ machine like elements highlight the relationship between the natural world and humanity’s intrusion; in doing so, Jeffers furthers Marx’s supposition that American literature continues to be impacted by the machine, by “forces working against the dream of pastoral fulfillment” (Marx 358).

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16

Lloyd, Ryan Allen. "Remote Sensing of Whitings in the Bahamas." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4361.

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Whitings on both the Great Bahama Bank (GBB) and Little Bahama Bank (LBB) were evaluated using data collected from 2000-2010 by the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments onboard the Terra and Aqua satellites. A semi-objective method was developed to classify whiting patches from other look-alike features using the recently developed Floating Algae Index (FAI) algorithm, an empirical cloud masking algorithm, and a gradient analysis from the 250-m resolution MODIS data. A total of 1,500 images with minimal cloud cover was used to calculate long-term and seasonal trends as well as an average daily coverage for both banks. Annual and monthly frequency of occurrences for whitings at every location was also calculated. Based on the results, the distribution of whitings over the GBB was restricted between 25–30'N and 23–45'N and occurred most frequently on the edge of the bank. Whitings were observed throughout the LBB and at much higher frequencies than in the GBB, especially on the east side from November to February. Results from daily whiting coverage indicate whitings cover nearly twice as much area over the LBB compared to the GBB. Whitings show a clear seasonal variation with respect to coverage on both banks. Whiting coverage over the LBB has a clear seasonal variation with peak coverage in spring (April) and fall (November) and minimum coverage during summer. Whiting coverage over the GBB peaks in spring (April), but no second peak or seasonal minimum was observed. Sea surface temperature (SST), photosynthetically available radiation (PAR) and wind were compared to the observed long-term and seasonal trends of whiting coverage. Using multi-variable analyses, the influence of SST and PAR on monthly whiting coverage over the GBB from 2000-2010 was found to be statistically significant, though the correlation between the three values was low. The results indicate that these parameters may not directly influence whiting origin and coverage but rather have an effect through influence mechanism, for example through phytoplankton blooms. It is hypothesized that whitings are directly influenced by cyanobacterial phytoplankton, which are dependent on SST and PAR. Long-term trends in whiting coverage differ between the two banks. In general, whiting coverage appeared to be decreasing from 2000-2010 over the LBB, while the opposite trend was observed over the GBB during the same time period. It is currently unclear what led to these opposite trends due to lack of long-term, in-situ measurements of the water environments in the two banks. However, this is the first study that documents the long-term trends for both banks, from which one may infer that the processes affecting whiting occurrence in the two banks vary greatly and future research is needed to understand the driving forces of whitings in order to improve the current understanding of their contributions in the global carbon cycle.

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17

Elder, Amor. "Using Remote Sensing to Evaluate Wetland Recovery in the Northern Tampa Bay Area Following Reduction in Groundwater Withdrawals." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6698.

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In the past, the Northern Tampa Bay Area (NTBA) wetlands saw severe declines in hydrologic conditions due to excessive groundwater withdrawal rates. Eventually these rates were reduced to allow the wetlands to recover. To monitor this recovery, the Southwest Florida Water Management district (SWFWMD) set up a fieldwork based scoring methodology, called the Wetlands Assessment Procedure (WAP). WAP has been used in many studies of the area since groundwater withdrawal reductions; with many of those studies finding the recovery to be mixed at best. However, these studies were very limited in the number of wetlands they could assess due to the limitations of fieldwork. Therefore, it was proposed that remotely sensed variables associated with water consumption and stress be used to assess the recovery of the NTBA wetlands, as remote sensing allows for efficient assessments of targets over large area. Utilizing ASTER imagery scenes from 2005 and 2014, 211 wetlands’ remotely sensed responses of NDVI, Land Surface Temperature (LST), and Evapotranspiration (ET) were mapped and statistically examined for trends indicating improvement or decline. Furthermore, a subset of WAP scores for the two years were examined and compared to the remotely sensed values. The results were contradictory, with remotely sensed responses showing an improvement over the time period, WAP scores indicating a decline in hydrologic conditions, and the two methods showing little to no fit when modeled against each other. As such, it is believed at this time that the remotely sensed method is not suitable for measuring the indicators of wetland recovery used in the WAP methodology.

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Johansson, Sara. "Geoturism i Siljansområdet." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-180913.

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Tanken på att skapa en geopark, ett område med geovetenskapliga besöksmål, i Siljansområdet väcktes för flera år sedan. Idag arbetar Projekt Meteorum med att förverkliga denna idé. Utgångspunkten är det meteoritnedslag som formade landskapet här för 377 miljoner år sedan och som sedan dess haft stor betydelse för bygden och dess utveckling. Den geologiska historien i Siljansområdet är lång och inte helt lätt att förstå, som så ofta när vi försöker tolka det som hänt långt före vår egen tid. Den tar egentligen sin början för omkring 1 800 miljoner år sedan, då bergarterna i sydöst bildas i samband med att den svekofenniska bergskedjan reste sig. Det landskap som meteoriten träffade bildades under många årmiljoner. Fler bergarter bildades, berg höjde sig och eroderade ner, hav sköljde över land och drog sig tillbaka. Efter meteoritnedslaget följde många miljoner år under vilka nya lager av bergarter bildades och eroderades bort, senast genom istidens inverkan. Men än idag finns kraterstrukturen kvar och tack vare nedslaget är Siljansområdet idag en av mycket få platser i Sverige där vi kan studera de välbevarade sedimentära bergarterna. Här berättas en historia om livets utveckling och en planet i ständig förändring. De speciella förutsättningarna har utan tvekan påverkat så väl djur och natur som de människor som valde att bosätta sig här. Denna historia kan ge mycket glädje och ökad förståelse för såväl vår egen planet som den speciella plats Siljansområdet är. Att arbeta med att berätta den inom ramen för en geopark är ett utmärkt sätt att binda samman och belysa alla de delar som formar bygden idag. Där ryms såväl den säregna naturen som den viktiga kalkindustrin. Med meteoritnedslaget som centrum kommer besökare att lockas från hela världen för att uppleva allt Siljansområdet har att erbjuda.

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19

Barliaev, Aleftin. "Paleogeography and shore displacement of Eastern Gotland between 9.5 and 2.8 ka cal BP." Thesis, Stockholms universitet, Institutionen för naturgeografi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-149147.

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Located in the middle part of the Baltic, the island of Gotland underwent major environmental changes, associated with different stages of the development of the basin during the Holocene, and therefore represents a promising location for shore-displacement studies. This thesis is focused on a palaeohydrological evolution of the Lina Mire, central eastern part of Gotland, in the Middle Holocene and aims to reconstruct the timing and environment of the Littorina transgression. The research is based on a multi-proxy approach and carried out, applying lithostratigraphical, biostratigraphical (diatom analysis) and geochemical methods (XRF, organic and carbonate content) along with radiocarbon dating. The initiation of the Littorina transgression was constrained at 8.5 ka cal BP, however, probably proceeded by a hiatus. A two-folded pattern oft he maximum sub-phases is suggested. Acquired results fit well with previous studies on areas with the similar rate of apparent land uplift, suggesting an average rate of 2 mm/yr for the last 2.8 ka.
I Tjelvars fotspår

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20

Lundqvist, Jennie. "Geovetenskaplig analfabetism i Sverige – En undersökning av allmänhetens och beslutsfattarnas kunskaper." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-206150.

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Earth science is a dynamic system science that explores the structures and processes of the earth. Knowledge about the earth is important for citizens since the science is a vital part in the sustainable development of the society. Without good basic knowledge the citizens don’t have the possibility to anticipate in the questions and decision-making that concerns e.g. anthropogenic climate change. In the Swedish school system earth science is not an independent subject until academically studies at the University’s. The purpose of this study is to investigate the level of knowledge among citizens and policymakers in Sweden and to find out if there is any illiteracy for earth science in Sweden. The method conducted of two web-based surveys and the questions in the surveys are focused around the subject of anthropogenic climate change because it is one of the most well known areas of earth science amongst the citizens. The survey results are based on 159 answers from each survey and shows that there is illiteracy for earth science in Sweden. It is also possible to se that the policymakers have better knowledge about earth science than the citizens. The results also show that there is a concern amongst the citizens regarding the effects that humans do to anthropogenic climate change. One solution to the illiteracy and worries amongst the public is better education in earth science. How to best teach a subject is developed in the research area of didactics but for earth science this is a relatively young science, in need of more research both in Sweden and internationally.
Geovetenskap är en dynamisk systemvetenskap som utforskar jordens utveckling och uppbyggnad. Geovetenskapliga kunskaper är vitala för det moderna hållbara samhället, men i Sverige finns ämnet geovetenskap bara som fristående ämne på akademisk nivå. Utan grundkunskaper har medborgarna inte lika stora möjligheter att delta i debatter och fatta beslut i frågor som exempelvis antropogena klimatförändringar. Syftet med denna studie är att undersöka det geovetenskapliga kunskapsläget i Sverige och om frånvaron av denna undervisning i skolan/gymnasiet kan orsaka geovetenskaplig analfabetism. Undersökningen genomfördes via två internetbaserade enkäter en riktade sig mot Sverige allmänhet och en mot tjänstemän/politiker. Frågorna i enkäterna byggdes upp kring antropogena klimatförändringar då detta område är mer allmänt känt än ämnet geovetenskap och de övrigt innefattande områdena. Resultatet från undersökningen baseras på 159 svar från respektive enkät och visar att det finns en geovetenskaplig analfabetism i båda undersökningsgrupperna. Det går att utläsa en liten skillnad i kunskapsnivå mellan de två undersökningsgrupperna, beslutsfattare/tjänstemän har en något högre kunskapsnivå än allmänheten. Resultaten visar också att det finns en oro bland allmänheten för olika effekter av klimatförändringar som att Golfströmmen kan stanna och att antalet tsunamivågor kan komma att öka. Dessutom tror en mindre del (16%) av allmänheten att jordbävningen i Chile 2010 orsakades av antropogena klimatförändringar. För att kunna förbättra de geovetenskapliga kunskapsnivåerna krävs utbildning av både barn och vuxna. Dessutom krävs det mer forskning i geovetenskaplig didaktik som är ett ungt och outforskat område både i Sverige och internationellt.

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21

Andersson, Hanna. "Bradoriids from the middle Cambrian 'thin' Stephen Formation at Odaray Mountain, Canadian Rocky Mountains." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-227540.

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Two new species of Cambrian bradoriid arthropods have been found in the ‘thin’ Stephen Formation, Odaray Mountain, Canada; the hipponicharionid Flumenoglacies michaeli n. sp. and the comptalutid Phasoia stephenensis n. sp. This paper includes the description and illustrations of these species as well as two undetermined species from the same locality. Phasoia stephenensis n. sp. is the first Phasoia reported from Laurentia and Flumenoglacies michaeli n. sp. belongs to the new genus Flumenoglacies recently described by Peel & Streng (in press) from Greenland. In the discussion previous reports of the genus Phasoia are ordered chronologically and a migration path from Gondwana to Laurentia is suggested. However, more information on the stratigraphic and regional distribution of this taxon is needed to support this theory since Phasoia is so far only known from Australia, South China and now North America. The ornamentation of Phasoia stephenensis n. sp. and Flumenoglacies michaeli n. sp. is discussed and compared with the ornamentation of the hipponicharion Pseudobeyrichona longquanxiensis (Cui 1987), the svealutid Tsunyiella Zhang (1974) and the cambriid Petrianna fulmenata Siveter (1995). It is suggested that it might be remnants of a respiratory system.

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22

Edberg, Elin. "Kartläggning av sulfidleror i Uppsala stad." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-192313.

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A large part of the center of the city of Uppsala is located on postglacial clay. This clay often contain sulfur, this in the form of sulfide, and thus it is generally called sulfide clay (or sulfidlera in Swedish). The amount of sulfide in the clay varies from location to location. When the sulfide-rich postglacial clay comes in contact with the air it oxidizes and can give rise to acid leachate and leaching of heavy metals that were bound to the sediments. The knowledge of this has made the interest of sulfide content in soils greater in recent years, this during for example excavations on building sites. The aim of this project is therefore to summarize and present data related to sulfiderich sediments in a perspicuous way, and thus make it easier to survey the measures that could be necessary to take into consideration for construction work in the city of Uppsala. A lot of the data is taken from the archive of Bjerking AB, but some of the information on sites with sulfide rich clay is taken from Miljökontoret. Using the computer program MapInfo, the locations with sulfide rich soils has been marked on a map of Uppsala and additional information about for instance layering, NNP and pH is connected to these markings, though this is only viewable together with the map in a program supporting the “.tab” file format.
Uppsala stad ligger till stor del på postglacial lera. Denna lera innehåller ofta svavel i form av sulfid och brukar kallas ”sulfidlera”. Lerans sulfidhalt varierar från lokal till lokal. När den sulfidhaltiga postglaciala leran kommer i kontakt med luft oxiderar den och kan då ge upphov till surt lakvatten och urlakning av tungmetaller som är bundna i sedimenten. Vetskapen om detta har gjort att man på senare år börjat intressera sig mer för markens sulfidhalt vid exempelvis schaktning. Syftet med detta arbete att på ett enkelt sätt sammanställa data relaterade till sulfidhaltiga sediment och på så vis ge en överblick över vilka åtgärder som skulle behöva vidtas vid byggnation i Uppsala stad. Mycket data är taget från Bjerking AB's arkiv men också enstaka uppgifter om sulfidlera hämtade från Miljökontoret har använts. Med hjälp av programmet MapInfo har de platser, där sulfidhaltiga sediment hittats, märkts ut på en karta över Uppsala och information om bland annat lagerföljd, NNP och pH har kopplats till dessa punkter.

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Nyberg, Andreas. "Adsorption av cesium på krossad granit - en faktor inför slutförvaret av kärnbränsle." Thesis, Uppsala universitet, Institutionen för geovetenskap, 1997. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-391686.

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Sedan några år tillbaks utvecklas vid Institutionen för geovetenskap, sedimentologi, Uppsala Universitet en modell för att simulera transportförloppet av radionuklider vid ett eventuellt läckage av kärnbränsleavfall deponerat långt nere i berggrunden. Som en viktig del av transportförloppet ingår adsorption av cesiumjoner på bergets sprickväggar. Adsorptionsprocessen har i detta examensarbete studerats genom att blanda varierande koncentrationer av granitpartiklar från olika fraktioner med cesiumkontaminerat grundvatten. Koncentrationen av cesiumjoner mättes m h a en gammaräknare tills jämvikt mellan de adsorberade och de lösta jonerna infann sig. Adsorptionen karakteriserades beroende på partikelstorleken av en enstegskinetik eller en tvåstegskinetik. Tvåstegsadsorptionen är en följd av att större partiklar innehåller betydligt fler mikrosprickor än vad de mindre partiklarna gör. Resultaten utvärderades m a p dels distributionskoefficienten kd och dels reaktionskonstanten kr. Anpassningen av kd-värdena gav ett mycket bra resultat med ett R2-värde över 0,99 medan anpassningen av kr inte alls var lika bra (R2 ≈ 0.36), vilket antas bero på att uttrycket för nettoadsorptionen G är felaktigt.
Over the last few years, a model that simulates the transport of radionuclides in fractured rock has been developed at the Department of Earth Sciences/Sedimentology, Uppsala University, Sweden. The aim has been to predict the outcome of a possible leak from deposits of nuclear waste fuel in deep bedrock. The adsorption of cesium ions at the fractures is an important part of the transport mechanism. This study has attempted to explore the adsorption kinetics of cesium ions at the surface of granite particles. A certain amount of cesium was mixed with synthetic groundwater along with different fractions and amounts of clean granite particles. The concentration of cesium in the liquid was frequently measured in order to estimate the change in cesium adsorption with time. The measurements were carried out until an equilibrium between adsorbed and solute ions was achieved. Depending on the size of the particles, the adsorption was characterized by either a one- or a two step kinetics. The reason for this was that larger particles contain micro fractures which affect the adsorption curve. The results were evaluated from the estimated values of the distribution coefficient kd and the reactivity coefficient kr. A model that evaluates the available surface of the rock gave very good results for the kd-values with a R2-value above 0.99. The fitting of kr was not by near equally good (R2 ≈ 0.36), and this is assumed to depend on an incorrect expression of the net adsorption G.

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Lundgren, Lisa, Karin Lindqvist, Simon Ene, Oskar Ahlstedt, Sandra Norberg, Olof Lood, and Maria Haglund. "Analys av vegetationen i brandområdena 2018." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-384451.

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Syftet med projektet var att analysera och kartlägga vilken typ av vegetation som brann under skogsbränderna sommaren 2018. Geografiskt informationssystem, GIS, nyttjades för att analysera den geografiska data som användes för att få fram vegetationsfördelningar i brandområdena. I analysen och kartläggningen användes Naturvårdsverkets öppna Nationella Marktäckedata tillsammans med Skogsstyrelsens dataset Ungefärligt brandområde. Marktäckedata är uppbyggd av olika klasser och representerar olika typer av information, exempelvis dominerande vegetationstyp. Genom arbetet i GIS togs det fram kartor över brandområdenas marktäckedata samt cirkeldiagram och tabeller med vegetationsfördelningar. Dessa analyserades för att hitta trender i vegetationens fördelning som förklarar skogsbrändernas spridning. Efter analysen kunde slutsatsen dras att det framförallt var barrskog som brann, där vegetationstypen tallskog utgjorde den största andelen. Samtidigt stod lövskog för en mycket liten del av vegetationsfördelningen i de sex största bränderna. Eftersom det generellt var lite lövskog i områdena kring skogsbränderna var det svårt att dra slutsatser kring huruvida lövskog är brandhämmande. Våtmarker verkar i vissa fall hindrat brandspridning men brann även de när det var torrt och varmt. I det initiala skedet i brandförloppet dominerade tallskog och temporärt ej skog såsom kalhyggen eller stormfällda områden, medan andra vegetationstyper involverades allt eftersom bränderna tog fart och spred sig.

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25

Nair, Sumit. "Stora Karlsö Tourism Sustainability Studies - A case study to understand & investigate impacts of water shortage and power outage on tourism." Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-384670.

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26

Klemm, Maria. "Economic Feasibility of Wind Turbine's Anti-Icing Systems Development and application of a simple heuristic method and tool." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-305278.

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Wind energy projects in cold climate areas are more and more favoured due to the presence of high wind potential and the availability of land in those areas. A serious problem, however, is the impact of icing on the wind turbine and on the energy production. The main objective of this Thesis is to present the available options for mitigating the risks of wind turbines’ blade icing and to evaluate the investment of the wind turbines’ anti-icing systems. To this end, a heuristic algorithmic method has been developed as well as a simple computational tool in order to assess the economic feasibility of anti-icing systems. The method has subsequently been applied in three case studies and relevant conclusions have been drawn Initially a literature review has been conducted that encompassed issues like the direct and indirect impacts of icing on wind turbines (reduced yield, increased loads and noise emission, health and safety risks, etc.), the difficulties of estimating icing formulation and icing production losses and the anti-icing and de-icing systems and their functionality, advantages and disadvantages. Subsequently, the heuristic algorithmic method has been developed which is based on estimating the energy production of a wind turbine for three scenarios - with no icing occurring, with icing but without any anti- and de-icing system installed and with an anti-icing system installed – followed by a sensitivity analysis of the economic performance parameter, the simple pay-back period. The method has been accommodated in a simple computational excel-based tool and has been applied to three case studies located in the north Norway, in central Sweden and in south Finland. The production losses related to icing are in the expected ranges typical for the geographic location and so is the economic performance parameter which indicate that the investment in an anti-icing system is recommended for the three case studies. Results showed that the wind resources, the electricity export price and the annual icing hours are the parameters that determine the feasibility of an anti-icing system for a wind farm project. Wind energy projects in cold climate areas are more and more favoured due to the presence of high wind potential and the availability of land in those areas. A serious problem, however, is the impact of icing on the wind turbine and on the energy production. The main objective of this Thesis is to present the available options for mitigating the risks of wind turbines’ blade icing and to evaluate the investment of the wind turbines’ anti-icing systems. To this end, a heuristic algorithmic method has been developed as well as a simple computational tool in order to assess the economic feasibility of anti-icing systems. The method has subsequently been applied in three case studies and relevant conclusions have been drawn Initially a literature review has been conducted that encompassed issues like the direct and indirect impacts of icing on wind turbines (reduced yield, increased loads and noise emission, health and safety risks, etc.), the difficulties of estimating icing formulation and icing production losses and the anti-icing and de-icing systems and their functionality, advantages and disadvantages. Subsequently, the heuristic algorithmic method has been developed which is based on estimating the energy production of a wind turbine for three scenarios - with no icing occurring, with icing but without any anti- and de-icing system installed and with an anti-icing system installed – followed by a sensitivity analysis of the economic performance parameter, the simple pay-back period. The method has been accommodated in a simple computational excel-based tool and has been applied to three case studies located in the north Norway, in central Sweden and in south Finland. The production losses related to icing are in the expected ranges typical for the geographic location and so is the economic performance parameter which indicate that the investment in an anti-icing system is recommended for the three case studies. Results showed that the wind resources, the electricity export price and the annual icing hours are the parameters that determine the feasibility of an anti-icing system for a wind farm project.

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27

Nordheim-Shelt, Barbara Ann. "Effects of Anthropogenic Activity on the Green Swamp Preserve Ecosystem." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6734.

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The Green Swamp Preserve is a large geographic area that has sustained many changes since Europeans settled in Florida. There has been little published research on the impacts of anthropogenic activity on this system. This thesis research seeks to document more recent changes in the Green Swamp and to evaluate the effects of various human activities on the system. The study period is from 1985 to 2015. For this time period changes in land use and landcover were examined using neural network classifications. Changes in vegetation health were evaluated by examining Normalized Difference Vegetation Index (NDVI) and Green Vegetation Index differences. Field site visits were made to document current conditions at thirty sample locations within the study area. Changes in land use and landcover and vegetation health were evaluated in relation to anthropogenic activities such as proximity to pollution sources, conservation lands and restoration sites. Statistical analysis was conducted to determine if statistically significant clustering occurred in these changes and if present geographically weighted regressions were performed to determine if a significant spatial relationship existed between the clustering and the various human activities. WAP data showed an overall decline in wetland health at the assessment sites and showed a trend of lower wetland health at sites within 2 Km of pollution sources, specifically petroleum tank contamination sites and state roads. The statistically significant clustering identified in land use landcover changes from 1985 to 2015 were in relation to changes from field, forested and wetland landcover types to built environments. Spatial relationships were identified between the proximity of petroleum tank contamination sites, state roads and solid waste facilities and clustering of NDVI decreases from 1985 to 2015. NDVI increases in the study area from 1985 to 2015 also showed statistically significant clustering in relation to conservation lands and lands purchased by the Southwest Florida Water Management District for environmental protection. These preliminary findings suggest that human activities may have influenced changes in the health of the Green Swamp. Further, more extensive research is suggested to confirm these findings.

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28

Reimark, Josefin. "How has time and space affected plant biodiversity in the Hjälmö-Lådna archipelago?" Licentiate thesis, Stockholms universitet, Institutionen för naturgeografi och kvartärgeologi (INK), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-79230.

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Traditionally European farmland management has declined during the last century, mainlydue to abandonment or intensification. When traditional management is replaced by newmethods many species are negatively affected and often threatened with extinction. In thisthesis, the Stockholm archipelago is used as a platform to study the effects of land use changeover time. The overall aim is to examine how time and space affects plant biodiversity in arural landscape, with focus on heterogeneous pastures. Historical records and maps were interpreted together with aerial photos and used to constructfour time-layers of land use: reflecting the landscape 200 years ago, 100 years ago, 50 yearsago and present. Investigations of plant species richness was conducted in seven habitats; 1)grazed fields, 2) grazed forest edges, 3) grazed forest interior, 4) former grazed fields, 5)former grazed forest edges, 6) former grazed forest interior, and 7) historical pasture islands,on 35 islands in Hjälmö-Lådna archipelago on the east-coast of Sweden. Plant speciesrichness was measured for all plant species and for grassland specialist species at three scales:i) fine-scale diversity (α div), ii) large-scale diversity (γ div ), and iii) spatial turnover (β div).Using Structural Equation Models (SEM) the variation in species diversity and plantcommunity composition was investigated in relation to landscape context, space andmanagement history. The land use change in the Hjälmö-Lådna archipelago followed the general trends on themainland in Sweden and the rest of Europe with loss of traditional managed habitats, such asmeadows or wooded pastures. However, no intensification and large-scale agriculture hasdeveloped on the islands, mainly because of physical limitations, but also because ofeconomical and conservation reasons. Surprisingly, the grazing pressure on the remaininggrazed habitats had not changed notable over the last century; although the study area was notparticularly species rich (highest average was 15 species/ m2 in grazed fields). Adjacenthabitats; field and wood pasture, showed a higher similarity in community composition thanexpected compared to random pairs. Grazing and proportion of openness had a positiveinfluence on species richness and especially on grassland specialists. The variation of totaldiversity at the landscape scale was best explained by the heterogeneity of grazed forest edgesand the local species diversity in fields. The results from the study suggest that grazing is important also in species-poor landscapes,and that it can aid in protecting and promote species-richness also in other types of speciespoorlandscapes. To prevent further loss of biodiversity it is necessary to keep fields andforest edges open with continuous management. To maintain values of high biodiversity andculture in the archipelago it is therefore important that farmers are subsidised by EU tocontinue to grazie heterogeneous habitats and pastures with many trees.

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Fürstenau, Cornelia. "The impact of silvicultural strategies and climate change on carbon sequestration and other forest ecosystem functions." Phd thesis, Universität Potsdam, 2008. http://opus.kobv.de/ubp/volltexte/2009/2765/.

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Forests are a key resource serving a multitude of functions such as providing income to forest owners, supplying industries with timber, protecting water resources, and maintaining biodiversity. Recently much attention has been given to the role of forests in the global carbon cycle and their management for increased carbon sequestration as a possible mitigation option against climate change. Furthermore, the use of harvested wood can contribute to the reduction of atmospheric carbon through (i) carbon sequestration in wood products, (ii) the substitution of non-wood products with wood products, and (iii) through the use of wood as a biofuel to replace fossil fuels. Forest resource managers are challenged by the task to balance these multiple while simultaneously meeting economic requirements and taking into consideration the demands of stakeholder groups. Additionally, risks and uncertainties with regard to uncontrollable external variables such as climate have to be considered in the decision making process. In this study a scientific stakeholder dialogue with forest-related stakeholder groups in the Federal State of Brandenburg was accomplished. The main results of this dialogue were the definition of major forest functions (carbon sequestration, groundwater recharge, biodiversity, and timber production) and priority setting among them by the stakeholders using the pair-wise comparison technique. The impact of different forest management strategies and climate change scenarios on the main functions of forest ecosystems were evaluated at the Kleinsee management unit in south-east Brandenburg. Forest management strategies were simulated over 100 years using the forest growth model 4C and a wood product model (WPM). A current climate scenario and two climate change scenarios based on global circulation models (GCMs) HadCM2 and ECHAM4 were applied. The climate change scenario positively influenced stand productivity, carbon sequestration, and income. The impact on the other forest functions was small. Furthermore, the overall utility of forest management strategies were compared under the priority settings of stakeholders by a multi-criteria analysis (MCA) method. Significant differences in priority setting and the choice of an adequate management strategy were found for the environmentalists on one side and the more economy-oriented forest managers of public and private owned forests on the other side. From an ecological perspective, a conservation strategy would be preferable under all climate scenarios, but the business as usual management would also fit the expectations under the current climate. In contrast, a forest manager in public-owned forests or a private forest owner would prefer a management strategy with an intermediate thinning intensity and a high share of pine stands to enhance income from timber production while maintaining the other forest functions. The analysis served as an example for the combined application of simulation tools and a MCA method for the evaluation of management strategies under multi-purpose and multi-user settings with changing climatic conditions. Another focus was set on quantifying the overall effect of forest management on carbon sequestration in the forest sector and the wood industry sector plus substitution effects. To achieve this objective, the carbon emission reduction potential of material and energy substitution (Smat and Sen) was estimated based on a literature review. On average, for each tonne of dry wood used in a wood product substituting a non-wood product, 0.71 fewer tonnes of fossil carbon are emitted into to the atmosphere. Based on Smat and Sen, the calculation of the carbon emission reduction through substitution was implemented in the WPM. Carbon sequestration and substitution effects of management strategies were simulated at three local scales using the WPM and the forest growth models 4C (management unit level) or EFISCEN (federal state of Brandenburg and Germany). An investigation was conducted on the influence of uncertainties in the initialisation of the WPM, Smat, and basic conditions of the wood product sector on carbon sequestration. Results showed that carbon sequestration in the wood industry sector plus substitution effects exceeded sequestration in the forest sector. In contrast to the carbon pools in the forest sector, which acted as sink or source, the substitution effects continually reduced carbon emission as long as forests are managed and timber is harvested. The main climate protection function was investigated for energy substitution which accounted for about half of the total carbon sequestration, followed by carbon storage in landfills. In Germany, the absolute annual carbon sequestration in the forest and wood industry sector plus substitution effects was 19.9 Mt C. Over 50 years the wood industry sector contributed 70% of the total carbon sequestration plus substitution effects.
Wälder beeinflussen in vielfältiger Weise unser Leben. Für den Waldbesitzer sind sie Einkommensquelle, die Holzindustrie versorgen sie mit dem Rohstoff, aus dem unzählige Dinge für den täglichen Bedarfs hergestellt werden, wie zum Beispiel Baumaterialien, Möbel, Gartengeräte, Spielzeug und Papier. Außerdem versorgen Wälder uns mit sauberem Grundwasser, sind Lebensraum für Pflanzen und Tiere und tragen somit zum Erhalt der Artenvielfalt bei. Nicht zuletzt beeinflussen Wälder das Klimasystem, da sie der Atmosphäre das Treibhausgas CO2 entziehen und Kohlenstoff in Biomasse und Boden speichern. Förster stehen nun vor der anspruchsvollen Aufgabe, eine Balance zwischen den vielfältigen und oft auch gegensätzlichen Waldfunktionen zu finden und die Ansprüche von Interessengruppen wahrzunehmen. Zusätzlich müssen im waldbaulichen Entscheidungsprozess Risiken und Unsicherheiten durch unberechenbare externe Faktoren, wie das Klima, beachtet werden. Ziel der Arbeit war es, den Einfluss von Klima und Waldbaustrategien auf Waldfunktionen zu untersuchen. Als Testgebiet fungierte das Revier Kleinsee im Südosten Brandenburgs, in dem Kiefern- und Eichenbestände vorherrschen. In einem wissenschaftlichen Dialog mit Angestellten der Forstbehörde, Privatwaldbesitzern, Vertretern von Naturschutzverbänden sowie Wissenschaftlern definierten die Teilnehmer die wichtigsten Waldfunktionen: Kohlenstoffspeicherung, Grundwasserneubildung, Biodiversität und Holzproduktion. Die Simulationen wurden mit Hilfe des Waldwachstumsmodells 4C und einem neu implementierten Holzproduktmodell (WPM) über einen Zeitraum von 100 Jahren durchgeführt. Dabei wurden den heutigen Klimabedingungen zwei Klimaänderungsszenarien gegenübergestellt, die auf den globalen Zirkulationsmodellen HadCM2 und ECHAM4 basieren. Es stellte sich heraus, dass unter den angenommenen Klimaänderungen das Wachstum der Bestände steigt und sich damit die Kohlenstoffspeicherung und der Ertrag aus Holzernten erhöht, wohingegen Biodiversität und Grundwasserneubildung nur sehr gering beeinflusst werden. Der Nutzen der Waldbewirtschaftungsstrategien für drei Interessensgruppen (Forstbehörde, private Waldbesitzer, Naturschutzvereine) wurde mit einer multikriteriellen Analysemethode bewertet. Dabei unterschieden sich die Rangfolge und Gewichtung der einzelnen Waldfunktionen sowie die daraus resultierende Wahl der Waldbaustrategien zwischen den Naturschützern einerseits sowie den stärker ökonomisch orientierten Landeswaldförstern und privaten Waldbesitzern anderseits. Naturschutzvereine bevorzugen das Einstellen der Waldbewirtschaftung, aber auch die aktuelle Waldbaustrategie, mit mäßiger Durchforstungsintensität und einem hohen Anteil an Eichenbeständen entspricht ihren Zielsetzungen. Dagegen lag die Präferenz der Landeswaldförster sowie privaten Waldbesitzer auf einer Walbaustrategie mit einem hohen Anteil an Kiefernbeständen, um den Ertrag unter Beachtung der anderen Waldfunktionen zu steigern. Als Fazit geht aus dieser Teilstudie hervor, dass die Bewertung von Waldbaustrategien hinsichtlich ihrer Eignung für eine multifunktionale Waldbewirtschaftung unter Beachtung von Ansprüchen verschiedener Interessengruppen und ungewissen klimatischen Bedingungen unter Verwendung von 4C und einer multikriteriellen Analysemethode sehr gut möglich ist. Besonderes Augenmerk galt dem Einfluss von Waldbaustrategien auf den Kohlenstoffkreislauf, wobei nicht nur die Kohlenstoffspeicherung im Wald, sondern auch in Holzprodukten, sowie die Verringerung von CO2-Emissionen durch energetische und stoffliche Nutzung von Holz betrachtet wurden. Die potentielle Reduktion von CO2-Emissionen durch das Ersetzen von Erzeugnissen und Energie aus nicht nachwachsenden Rohstoffen durch Holz (Smat und Sen) wurde basierend auf Daten verschiedener Studien geschätzt. Eine Sensitivitätsanalyse untersuchte Unsicherheiten bei der Initialisierung des WPMs und der Berechung von Smat. Verschiedene Szenarien führten zu einem besseren Verständnis dafür, wie sich Änderungen im Energiesektor und Holzproduktsektor auf das Potential, Kohlenstoff zu speichern bzw. CO2-Emissionen zu verringen auswirken. Die Ergebnisse zeigen, dass die Reduzierung von CO2-Emissionen im Holzproduktsektor durch die Nutzung von Holz als Werkstoff und Brennstoff höher ist als durch die Akkumulation von Kohlenstoff im Wald. Im Gegensatz zu den Kohlenstoffspeichern im Wald, die sowohl Quellen als auch Senken sein können, werden durch die Nutzung von Holz CO2-Emissionen verringert, solange im Zuge der Waldbewirtschaftung Holz für die Weiterverarbeitung zur Verfügung gestellt wird. Simulationen auf Bundesebene ergaben, dass in Deutschland die Forst- und Holzwirtschaft jährlich dazu beitragen die CO2-Emissionen um 19,9 Mt Kohlenstoff zu verringern, wobei 70% auf die Holzindustrie und den Substitutionseffekt entfallen.

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Hanslik, Daniela. "Late Quaternary Biostratigraphy and Paleoceanography of the central Arctic Ocean." Doctoral thesis, Stockholms universitet, Institutionen för geologiska vetenskaper, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-57245.

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The central Arctic Ocean is one of the least explored deep sea regions and long biostratigraphic sediment records are sparse. The main focus of this thesis is the Arctic Ocean foraminiferal record and its application to reconstruct paleoceanographic variations and summer sea ice cover changes between late Quaternary interglacial periods. One of the studied cores was retrieved from the central Lomonosov Ridge Intra Basin. This core contains a relatively high-resolution biostratigraphic record spanning Marine Isotope Stages (MIS) 1–3, although with a hiatus encompassing the Last Glacial Maximum. Radiocarbon age calibrations in this core show a decreasing trend of high marine reservoir ages of about 1400 years during the last deglaciation to 700 years in the late Holocene. The cores from the Lomonosov Ridge off Greenland and the Morris Jesup Rise contain preserved calcareous microfossils further back in time than most previously studied central Arctic Ocean cores. The calcium content estimated by X-ray fluorescence scanning of these cores shows a distinct pattern of calcium rich intervals coinciding with peaks in foraminiferal abundance in the sediment record of MIS 1–7. The calcium peaks originate from material accumulated during interglacials, primarily through detrital carbonate and dolomite input from the decaying North American ice sheet and secondarily from biogenic material. Intervals of calcareous benthic foraminifera are found in pre MIS 7 sediments on both the southern Lomonosov Ridge and Morris Jesup Rise. Their assemblage composition and stable carbon isotope data suggest increased primary production and decreased summer sea ice cover compared to the Holocene central Arctic Ocean. This is also suggested for an interval of high abundance of the subpolar planktic foraminifera Turborotalita quinqueloba on the southern Lomonosov Ridge with a proposed MIS 11 age.

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 3: Submitted.

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O'connor, Brendan. "Impacts of the Anomalous Mississippi River Discharge and Diversions on Phytoplankton Blooming in Northeastern Gulf of Mexico." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4736.

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On April 20, 2010 a tragic explosion aboard the Deepwater Horizon (DWH) drilling rig marked the beginning of one of the worst environmental disasters in history. For 87 days oil and gas were released into the Gulf of Mexico. In August 2010, anomalous phytoplankton activity was identified in the Northeastern Gulf of Mexico, using the Fluorescence Line Height (FLH) ocean color product. The FLH anomaly was bound by approximately 30-28 degrees North and 90 and 86 degrees West and there was a suggestion that this anomaly may have occurred due to the presence of oil. This study was designed to examine alternative explanations and to determine what influence the Mississippi River and the freshwater diversions, employed in the response efforts, may have had on the development of the FLH anomaly. The combination of the anomalously high flow rate in the Mississippi River observed in June-August 2010, the use of freshwater diversions, and three severe storms increased the flow of water through the adjoining marshes. We propose that these conditions reduced the residence time of water and nutrients on the wetlands, and likely mobilized nutrients leading to increased fresh water and nutrients being discharge to the coasts around the Mississippi Delta. Salinity contour maps created from data collected by ships operating in the Northeastern Gulf of Mexico showed that the 31 isohaline was upwards of 250km east of the Mississippi River Birds Foot Delta in August 2010. The American Seas (AmSeas) numerical circulation model was used to examine the dispersal and distribution of water parcels from the Mississippi River and freshwater diversions. Two virtual particle seeding locations were used to trace particles to obtain a measure of the percentage of particles entering a Region of Interest (ROI) located in the center of the FLH anomaly, i.e. 150 km east of the Mississippi Delta. All environmental data examined suggest that the eastward dispersal of the Mississippi River water including that derived from freshwater diversions and storm activity contributed to the development of FLH anomaly in August 2010. Chapter two examines the spectral characteristics of water and oil collected by the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). Several peaks in the spectral features of the total radiance of surface oil between 1907nm and 2400nm appear to be absent for water. An algorithm (Spectral Line Height) was created to measure the height of the peak at 2142nm relative to a baseline between 2013nm and 2390nm. A normalized difference technique developed by the USGS was used as a validation tool. Preliminary results of the SLH technique appear to compare favorably with the results derived using the USGS technique. The SLH technique worked in areas that did not show sunglint or shallow bottom features. Sunglint areas would require additional correction to remove the effect of specular reflection. The SLH technique shows promise but will require validation to develop into an operational remote sensing method.

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Wilson, Andrew Charles Bruce. "Popular geographies: celebrating the nation in Canadian Geographic, Australian Geographic and New Zealand Geographic, 1995-2004 : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Geography at Massey University, Palmerston North, New Zealand." Massey University, 2008. http://hdl.handle.net/10179/1090.

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Popular geography magazines like National Geographic (NG) provide readers with a lens of the world around them. Yet sadly they often only serve a limited utilitarian purpose as dust collectors on coffee tables of hospital waiting rooms or doctors’ practices. It should be of little surprise then that the relative importance of geographic magazines as a representational forum has been underestimated historically. The importance of geographic magazines as an outlet for creating and disseminating preconceived visions of what may be termed ‘popular geographies’ has only become the subject of scrutiny in the last two decades. Authors including Lutz and Collins (1993) and Rothenberg (1994, 2007) have reflected critically upon the place of NG as a powerful ideological institution for legitimating particular visions of the world in the wider corpus of the discipline of geography. Yet while there has been a substantial volume of work dedicated to unravelling the situated lens of NG there has been no research devoted to deciphering the lenses of other geography magazines such as Canadian Geographic (CG), Australian Geographic (AG) or New Zealand Geographic (NZG). These magazines also embody the ideals of adventure, discovery and nature made famous by NG but purvey geography through distinctively national narratives. Through discourse analysis the thesis examines these three magazines in order to unravel geographic imaginations of nationalism in CG, AG and NZG and in the process challenge divergent conceptions of geography itself as both an academic discipline and popular subject.

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Howard, Evan M. (Evan Michael). "Ecosystem metabolism in salt marsh tidal creeks and ponds : applying triple oxygen isotopes and other gas tracers to novel environments." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/109021.

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Thesis: Ph. D., Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2017.
Cataloged from PDF version of thesis. Page 216 blank.
Includes bibliographical references (pages 179-215).
Salt marshes are physically, chemically, and biologically dynamic environments found globally at temperate latitudes. Tidal creeks and marshtop ponds may expand at the expense of productive grass-covered marsh platform. It is therefore important to understand the present magnitude and drivers of production and respiration in these submerged environments in order to evaluate the future role of salt marshes as a carbon sink. This thesis describes new methods to apply the triple oxygen isotope tracer of photosynthetic production in a salt marsh. Additionally, noble gases are applied to constrain air-water exchange processes which affect metabolism tracers. These stable, natural abundance tracers complement traditional techniques for measuring metabolism. In particular, they highlight the potential importance of daytime oxygen sinks besides aerobic respiration, such as rising bubbles. In tidal creeks, increasing nutrients may increase both production and respiration, without any apparent change in the net metabolism. In ponds, daytime production and respiration are also tightly coupled, but there is high background respiration regardless of changes in daytime production. Both tidal creeks and ponds have higher respiration rates and lower production rates than the marsh platform, suggesting that expansion of these submerged environments could limit the ability of salt marshes to sequester carbon.
by Evan M. Howard.
Ph. D.

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Srebrenikovic, Amir. "Geografi på gott och ont : En studie om kriminella och polisens användning av geografiska förutsättningar." Thesis, Södertörn University College, School of Life Sciences, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-2193.

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Undersökningen behandlar hur kriminella personer och polisen använder sig av geografiska förutsättningar i sina respektive verksamheter. Hur de först kartlägger objekt i sin omgivning för att sedan välja hur de ska agera. Kriminella personer och polisen undersöks för att visa hur aktörer, på olika sida om lagen, möter liknande geografiska förutsättningar fast upplever dem på olika sätt. Avslutningsvis återges deras inställning till att först kartlägga objekt i sin omgivning innan de agerar. Undersökningen skildrar hur aktörer subjektivt upplever objektiva föremål i sin omgivning på olika sätt, beroende på deras avsikter.

Kriminella personer planerar ett brott genom att först kartlägga sin omgivning. Det leder till att de sedan kan avgöra hur de ska agera på brottsplatsen. De beger sig till brottsplatsen en tid innan brottet ska utföras. På brottsplatsen undersöker de människors dagliga rutiner och hur objekt som exempelvis byggnader är placerade, för att kunna underlätta deras brott. De kriminella har angett vilken tid på dygnet ett brott är som mest gynnsamt för dem. Om de inte kan utföra ett brott under en särskild tid ökar risken för att gripas. Objekt i en omgivning kan skapa tillfällen och försvåra för kriminella att genomföra brott. Deras erfarenhet bidrar till att hitta tillfällen som lämpar sig för brott i en omgivning. Svårigheter anser de vara andra människor som befinner sig på en brottsplats och väderförhållanden.

I polisens arbete kartläggs objekt i omgivningen utförligt, eftersom de inte vill riskera att skada andra poliser, misstänkta eller allmänheten, när de ska agera i arbetet. På en brottsplats försöker de säkra bevismaterial beroende på brottsplatsens förutsättningar. Polisen vill göra ett gripande på säkrast möjliga sätt, i annat fall kan en polisaktion komma att avbrytas. Det kan handla om att gripa en misstänkt under en särskild tid på dygnet. Under ett spaningsarbete ska enskilda poliser själva kartlägga sin omgivning och avgöra hur en förflyttning ska ske. Polisspanare måste ständigt förnya och omvärdera sin omgivning. Både polisen och kriminella anser att de inte kan utföra respektive arbete utan att först ta hänsyn åt de objekt som finns i en omgivning. De resonerar om varandras agerande och uppfattar liknande objekt i omgivningen. Dessa upplever de sedan på olika sätt, till följd av deras avsikter i arbetet.

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Soto, Ramos Inia Mariel. "Harmful Algal Blooms of the West Florida Shelf and Campeche Bank: Visualization and Quantification using Remote Sensing Methods." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4775.

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Harmful Algal Blooms (HABs) in the Gulf of Mexico (GOM) are natural phenomena that can have negative impacts on marine ecosystems on which human health and the economy of some Gulf States depends. Many of the HABs in the GOM are dominated by the toxic dinoflagellate Karenia brevis. Non-toxic phytoplankton taxa such as Scrippsiella sp. also form intense blooms off the Mexican coast that result in massive fish mortality and economic losses, particularly as they may lead to anoxia. The main objectives of this dissertation were to (1) evaluate and improve the techniques developed for detection of Karenia spp. blooms on the West Florida Shelf (WFS) using satellite remote sensing methods, (2) test the use of these methods for waters in the GOM, and (3) use the output of these techniques to better understand the dynamics and evolution of Karenia spp. blooms in the WFS and off Mexico. The first chapter of this dissertation examines the performance of several Karenia HABs detection techniques using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite images and historical ground truth observations collected on the WFS from August 2002 to December 2011. A total of 2323 in situ samples collected by the Florida Fish and Wildlife Research Institute to test for Karenia spp. matched pixels with valid ocean color satellite observations over this period. This dataset was used to systematically optimize variables and coefficients used in five published HAB detection methods. Each technique was tested using a set of metrics that included the F-Measure (FM). Before optimization, the average FM for all techniques was 0.47. After optimization, the average FM increased to 0.59, and false positives decreased ~50%. The addition of a Fluorescence Line Height (FLH) criterion improved the performance of every method. A new practical method was developed using a combination of FLH and Remote Sensing Reflectance at 555 nm (Rrs555-FLH). The new method resulted in an FM of 0.62 and 3% false negatives, similar to those from more complex techniques. The first chapter concludes with a series of recommendations on how to improve the detection techniques and how to take these results a step further into a Gulf wide observing systems for HABs. In chapter two, ocean color techniques were used to examine the extension, evolution and displacement of four Karenia spp. events that occurred in the WFS between 2004 and 2011. Blooms were identified in the imagery using the new Rrs-FLH method and validated using in situ phytoplankton cell counts. The spatial extension of each event was followed in time by delineating the blooms. In 2004 and 2005, the WFS was affected by a series of hurricanes that led to high river discharge and intense sediment resuspension events. Both processes had an impact on HAB occurrence. For example, I tracked a Karenia spp. bloom found in late December 2004 approximately 40-80 km offshore Saint Petersburg, which then expanded reaching an extension of >8000 km2 in February 2005. The bloom weakened in spring 2005 and intensified again in summer reaching >42,000 km2 after the passage of hurricane Katrina in August 2005. This bloom covered the WFS from Charlotte Harbor to the Florida Panhandle. Two other cases were studied in the WFS. The results of the Hybrid Coordinate Ocean Model from the U.S. Navy aid understanding the dispersal of the blooms. During fall 2011, three field campaigns to study HABs in Mexico were conducted to do an analysis of optical properties and explore the possibility of using ocean color techniques to distinguish between the main phytoplankton blooms in that region. Three main bloom scenarios were observed in the Campeche Bank region: massive diatom blooms, blooms dominated by Scrippsiella spp., and Karenia spp. blooms. The normalized specific phytoplankton absorption spectra were found to be different for Karenia spp. and Scrippsiella sp. blooms. A new technique that combines phytoplankton absorption derived from MODIS data and the new technique developed in Chapter One showed potential for a detection technique that can distinguish between Karenia and Scrippsiella blooms. Additional work is needed to improve the new technique developed for Mexican waters, but results show potential for detection techniques that can be used Gulf-wide. This will help better understand the dynamic and possible connectivity of phytoplankton blooms in the GOM.

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Martinez, Diego A. "Informing the Design and Deployment of Health Information Technology to Improve Care Coordination." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5987.

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In the United States, the health care sector is 20 years behind in the use of information technology to improve the process of health care delivery as compared to other sectors. Patients have to deliver their data over and over again to every health professional they see. Most health care facilities act as data repositories with limited capabilities of data analysis or data exchange. A remaining challenge is, how do we encourage the use of IT in the health care sector that will improve care coordination, save lives, make patients more involved in decision-making, and save money for the American people? According to Healthy People 2020, several challenges such as making health IT more usable, helping users to adapt to the new uses of health IT, and monitoring the impact of health IT on health care quality, safety, and efficiency, will require multidisciplinary models, new data systems, and abundant research. In this dissertation, I developed and used systems engineering methods to understand the role of new health IT in improving the coordination, safety, and efficiency of health care delivery. It is well known that care coordination issues may result in preventable hospital readmissions. In this dissertation, I identified the status of the care coordination and hospital readmission issues in the United States, and the potential areas where systems engineering would make significant contributions (see Appendix B). This literature review introduced me to a second study (see Appendix C), in which I identified specific patient cohorts, within chronically ill patients, that are at a higher risk of being readmitted within 30 days. Important to note is that the largest volume of preventable hospital readmissions occurs among chronically ill patients. This study was a retrospective data analysis of a representative patient cohort from Tampa, Florida, based on multivariate logistic regression and Cox proportional hazards models. After finishing these two studies, I directed my research efforts to understand and generate evidence on the role of new health IT (i.e., health information exchange, HIE) in improving care coordination, and thereby reducing the chances of a patient to be unnecessarily readmitted to the hospital. HIE is the electronic exchange of patient data among different stakeholders in the health care industry. The exchange of patient data is achieved, for example, by connecting electronic medical records systems between unaffiliated health care providers. It is expected that HIE will allow physicians, nurses, pharmacists, other health care providers and patients to appropriately access and securely share a patient’s vital medical information electronically, and thereby improving the speed, quality, safety and cost of patient care. The federal government, through the 2009 Health Information Technology for Economic and Clinical Health (HITECH) Act, is actively stimulating health care providers to engage in HIE, so that they can freely exchange patient information. Although these networks of information exchange are the promise of a less fragmented and more efficient health care system, there are only a few functional and financially sustainable HIEs across the United States. Current evidence suggests four barriers for HIE: •Usability and interface issues of HIE systems •Privacy and security concerns of patient data •Lack of sustainable business models for HIE organizations •Loss of strategic advantage of "owning" patient information by joining HIE to freely share data To contribute in reducing usability and interface issues of HIE systems, I performed a user needs assessment for the internal medicine department of Tampa General Hospital in Tampa, Florida. I used qualitative research tools (see Appendix D) and machine learning techniques (see Appendix E) to answer the following fundamental questions: How do clinicians integrate patient information allocated in outside health care facilities? What are the types of information needed the most for efficient and effective medical decision-making? Additionally, I built a strategic gaming model (see Appendix F) to analyze the strategic role of "owning" patient information that health care providers lose by joining an HIE. Using bilevel mathematical programs, I mimic the hospital decision of joining HIE and the patient decision of switching from one hospital to another one. The fundamental questions I tried to answer were: What is the role of competition in the decision of whether or not hospitals will engage in HIE? Our mathematical framework can also be used by policy makers to answer the following question: What are the optimal levels of monetary incentives that will spur HIE engagement in a specific region? Answering these fundamental questions will support both the development of user-friendly HIE systems and the creation of more effective health IT policy to promote and generate HIE engagement. Through the development of these five studies, I demonstrated how systems engineering tools can be used by policy makers and health care providers to make health IT more useful, and to monitor and support the impact of health IT on health care quality, safety, and efficiency.

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Guo, Qiandong. "A Comparative Study on Coastal Zone Changes and Anthropogenic Impacts between Tampa Bay, USA, and Xiangshan Harbor, China, during the Last 30 Years." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7292.

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Currently, the U.S. and China are the two largest national economic entities in the world. However, it is noticeable that the two countries have considerably different strategies for economic development, environmental protection and land supply in coastal zones. In order to understand the coastline dynamics, land use land cover (LULC) changes and land management policies in the U.S. and China, a case study of the Tampa Bay (TB) watershed, Florida, U.S., and Xiangshan Harbor (XH), Zhejiang Province, China was conducted. The two areas possess similar humid subtropical climate and dense population, but experienced different anthropogenic impacts. TB sat at a developed stage with sound environmental laws, regulations and projects to preserve natural landscapes. XH was at a developing stage and focused more on an economic development in the last 30 years. Comparing the LULC change patterns and the major driving forces for the changes between the two study areas, governments and public could know what factors cause the land use conversion and how to preserve the natural landscapes. A new water index called the weighted normalized water index (WNDWI) was proposed to extract coastlines in TB and XH since current water indices could not classify turbid water bodies and shadow areas well. Two threshold methods (i.e., Otsu threshold method and multiple thresholds method) were implemented to find an optimal threshold to segment the water from the land. The experiments demonstrate that the WNDWI algorithm can achieve high accuracies to classify water from land with an optimal threshold in the two study sites. Coastlines in 1985, 1995, 2005 and 2015 in TB and XH were extracted and the changes were detected and highlighted. The results indicate that coastlines in TB were mostly stable, while those in XH had been undergoing intensive human interferences, indicating that XH was at a developing stage. Major anthropogenic impacts on XH coastlines are land reclamation and aquaculture, resulting in an impacted area of approximately 20.3 km2. The land cover maps of TB and XH in 1985 (1986), 1995, 2005 and 2015 were produced by classifying Landsat images using the random forest algorithm. The reflectance distributions of the land cover types indicate that it is difficult to classify agricultural land, rangeland, upland forest and wetland if using the optical bands only from a single Landsat image. Multi-seasonal image composites and the land surface temperature (LST) band were involved in image classification to achieve higher accuracies. The overall accuracies (OAs) of the land cover map of TB in 2015 and that of XH in 2005 were increased by 5.14% and 4.33% after adding the LST band. The OAs of the four years’ land cover maps of TB range from 81.14% to 83.43%, whereas those of XH vary from 84.67% to 87.67%. According to the experimental results, the total urban area increased by 11.8% in TB, while that in XH increased 138.9% during the last 30 years. Wetland in TB reduced by 8.3% while that in XH reduced 49.0%. The results of logistic regression analysis indicated that the density of wetland is a major driver for urban growth in TB with a strong negative impact while the relationship is opposite in XH. It is worth noting that XH has been undergoing a rapid urbanization and industrialization process with a vast amount of natural landscapes converted to urban areas, whereas TB has already passed the developing stage and issued environmental laws and programs to preserve natural landscapes from human exploitation. In terms of preserving natural landscapes and protecting the vulnerable coastal environment for our next generation, the coastal planning decision makers in XH should not only consider economic values and short-term benefits but also integrate values of ecological, social, and cultural and long-term benefits when making coastal management decisions.

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Gonzalez, Israel. "Linear and Nonlinear Motion of a Barotropic Vortex." FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1196.

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The linear Barotropic Non-Divergent simulation of a vortex on a beta plane is consistent with Willoughby’s earlier shallow-water divergent results in that it produced an unbounded accelerating westward and poleward motion without an asymptotic limit. However, Montgomery’s work which yielded finite linear drift speeds for his completely cyclonic vortex was inconsistent with ours. The nonlinearly-forced streamfunction exhibited a beta-gyre like structure, but with opposite polarity phase to the linear gyres. Utilization of the linear model with time-dependent, but otherwise beta-like, forcing revealed increasing magnitude and phase reversal in the neighborhood of a low cyclonic frequency. Here, the mean bounded vortex has an outer waveguide that supports Vortex Rossby Wave propagation that is faster than the mean flow and confined to a very narrow band of frequencies between zero and the Vortex Rossby Wave cutoff. The low frequency waves constitute the beta-gyre mode described previously by Willoughby.

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Kukat, James Pkemoi. "Development and Validation of a Remote Sensing Model to Identify Anthropogenic Boreholes that Provide Dry Season, Refuge Habitat for Anopheles Vector Mosquitoes in Sub-Saharan Africa." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6287.

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A lack of surveillance systems is an impediment to public health intervention for perennial vector-borne disease transmission in northern tropical savanna region of Kenya. The population in this area are mostly poor nomadic pastoralists with little acquired functional immunity to Plasmodium falciparum, due to infrequent challenges with the parasite. A common characteristic in tropical savanna climatic zone is the availability of riverbeds that have anthropogenic boreholes that provide malaria vector mosquitoes, such as Anopheles gambiae s.l and Anopheles funestus, with aquatic refuge habitats for proliferation and endemic transmission to proximity human households during the dry-season. Unfortunately, currently there have been no entomological investigations employing field or remotely sensed data that can characterize and model anthropogenic borehole habitats focusing on the dry-land ecology of immature Anopheles mosquitoes in sub-Sahara Africa. The goal of this investigation was three-fold: (I) to employ WorldView-3 (0.31 meter spatial resolution) visible and near infra-red waveband sensor data to image sub-Saharan land cover associated with vector-borne disease transmission; (II) to remotely identify anthropogenic boreholes in three riverbeds that were surveyed to determine whether they provide malaria vectors with refuge habitat and maintain their population during the dry season in Chemolingot, Kenya, and (III) to obtain a radiometric/spectral signature model representing boreholes from the remotely-sensed data. The signature model was then interpolated to predict unknown locations of boreholes with the same spectral signature in Nginyang Riverbed, Kenya. Ground validation studies were subsequently conducted to assess model’s precision based on sensitivity and specificity tests.

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Cui, Zheng. "A Generalized Adaptive Mathematical Morphological Filter for LIDAR Data." FIU Digital Commons, 2013. http://digitalcommons.fiu.edu/etd/995.

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Airborne Light Detection and Ranging (LIDAR) technology has become the primary method to derive high-resolution Digital Terrain Models (DTMs), which are essential for studying Earth’s surface processes, such as flooding and landslides. The critical step in generating a DTM is to separate ground and non-ground measurements in a voluminous point LIDAR dataset, using a filter, because the DTM is created by interpolating ground points. As one of widely used filtering methods, the progressive morphological (PM) filter has the advantages of classifying the LIDAR data at the point level, a linear computational complexity, and preserving the geometric shapes of terrain features. The filter works well in an urban setting with a gentle slope and a mixture of vegetation and buildings. However, the PM filter often removes ground measurements incorrectly at the topographic high area, along with large sizes of non-ground objects, because it uses a constant threshold slope, resulting in “cut-off” errors. A novel cluster analysis method was developed in this study and incorporated into the PM filter to prevent the removal of the ground measurements at topographic highs. Furthermore, to obtain the optimal filtering results for an area with undulating terrain, a trend analysis method was developed to adaptively estimate the slope-related thresholds of the PM filter based on changes of topographic slopes and the characteristics of non-terrain objects. The comparison of the PM and generalized adaptive PM (GAPM) filters for selected study areas indicates that the GAPM filter preserves the most “cut-off” points removed incorrectly by the PM filter. The application of the GAPM filter to seven ISPRS benchmark datasets shows that the GAPM filter reduces the filtering error by 20% on average, compared with the method used by the popular commercial software TerraScan. The combination of the cluster method, adaptive trend analysis, and the PM filter allows users without much experience in processing LIDAR data to effectively and efficiently identify ground measurements for the complex terrains in a large LIDAR data set. The GAPM filter is highly automatic and requires little human input. Therefore, it can significantly reduce the effort of manually processing voluminous LIDAR measurements.

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Wang, Mengqiu. "Spatial and Temporal Distributions of Pelagic Sargassum in the Intra-Americas Sea and Atlantic Ocean." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7716.

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Pelagic Sargassum is one type of marine macroalgae that is known to be abundant in the Gulf of Mexico and Sargasso Sea. It is also known to serve as a critical habitat for many marine animals. In the past few years, large amounts of Sargassum have been reported in the Tropical Atlantic and Caribbean Sea (CS), causing significant environmental and economic problems. The goal of this study is to improve the understanding of Sargassum distributions, quantity, transport pathways, and bloom mechanisms in the CS and Tropic Atlantic through combining a variety of techniques including satellite remote sensing, field and laboratory measurements, and numerical modeling. The first question is where and how much Sargassum is in the CS and Tropic Atlantic. Previous field observations revealed strong seasonal and spatial variations of Sargassum, yet these observations are all limited in their spatial and temporal coverage. Satellite observations offer an effective means to measure their distributions with synoptic coverage and high sampling frequency, yet it is technically challenging to extract and quantify the small Sargassum features in coarse-resolution satellite imagery. Chapter 2 focuses on Sargassum detection and quantification algorithm development using Moderate Resolution Imaging Spectroradiometer (MODIS) data (Appendix A). The algorithm is based on MODIS alternative floating algae index (AFAI), which examines the red-edge reflectance of floating vegetation. The algorithm includes three basic steps: 1) classification of Sargassum-containing pixels through correction of large-scale gradient, masking clouds and cloud shadows, and removal of ambiguous pixels; 2) linear unmixing of Sargassum-containing pixels; and, 3) statistical analysis of Sargassum area coverage in pre-defined grids at monthly, seasonal, and annual intervals. The algorithm is applied to MODIS observations between 2000 and 2015 over the Central West Atlantic (CWA) region (0 – 22oN, 38 – 63oW) to derive the spatial and temporal distribution patterns as well as the total areal coverage of Sargassum. Results indicate that the first widespread Sargassum distribution event occurred in 2011, consistent with previous findings from the Medium Resolution Imaging Spectrometer (MERIS). Since 2011, only 2013 showed minimal Sargassum coverage similar to the period of 2000 to 2010; all other years showed significantly more coverage. More alarmingly, the summer months of 2015 showed mean coverage of > 2000 km2, or about 4 times of the summer 2011 coverage and 20 times of the summer 2000 to 2010 coverage. Analysis of several environmental variables provided some hints on the reasons causing the inter-annual changes after 2010, yet further multi-disciplinary research (including in situ measurements) is required to understand such changes and long-term trends in Sargassum coverage. To better understand the potential ecological and environmental impacts of Sargassum, field and laboratory experiments are conducted to link the Sargassum areal coverage observations to biomass per area (density) and measure the nutrient contents and pigment concentrations (Chapter 3, Appendix B). An AFAI-biomass density model is established to derive Sargassum biomass density from the spectral reflectance, with a relative uncertainty of ~ 12%. Monthly mean integrated Sargassum biomass in the CS and CWA reached > 4.4 million tons in July 2015. The average % C, % N, and % P per dry-weight, measured from samples collected in Gulf of Mexico and Florida Straits in summer 2017, are 27.16, 1.06, and 0.10, respectively. The mean chlorophyll-a concentration is ~ 0.05% of the dry-weight. With these parameters, the amounts of nutrients and pigments can be estimated directly from remotely-sensed Sargassum biomass. During bloom seasons, Sargassum carbon can account for ~ 18% of the total particulate organic carbon in the upper water column. This chapter provides the first quantitative assessment of the overall Sargassum biomass, nutrients, and pigment abundance from remote-sensing observations, thus helping to quantify their ecological roles and facilitate management decisions. To investigate the Sargassum transport patterns and potential bloom sources, a Lagrangian particle tracking model is established to track the Sargassum transport driven by surface currents and winds (Chapter 4, Appendix C). The mean Sargassum distributions derived from MODIS observations are used to initiate and evaluate a Lagrangian particle tracking model that tracks Sargassum advection under surface currents and winds. Among the thirty-nine experiments, adding surface currents alone improves model performance (i.e., by reducing difference between modeled and observed Sargassum distributions) in 82% of the cases after tracking Sargassum for one month. Adding 1% wind forcing to the advection model also shows improved performance in 67% of the cases. Adding a time- and location-dependent Sargassum growth/mortality rate (i.e., change rate), derived from time-series of the MODIS-based Sargassum abundance and the corresponding environmental data via a Random Forest regression, leads to further improvement in model performance (i.e., by increasing the matchup percentage between modeled and observed Sargassum distributions) in 64% of the cases, although the modeled change rates only explain ~ 27% of the variance of the validation dataset, possibly due to uncertainties in such-derived change rates. The Sargassum transport model, with the mean currents, winds, and change rates acting as the forcing, is applied to track the mean Sargassum distributions forward and backward. The results demonstrate the model’s capacity of simulating the Sargassum distribution patterns, with emphasis on the role of biological terms in determining the large-scale distributions. These tracking experiments also suggest that Sargassum blooms in the CS are strongly connected to the Central Atlantic regions, and blooms in the Tropical Atlantic show relatively weak connections to the Atlantic regions further north. Although it is straightforward to apply the transport model to predict Sargassum blooms, such long-term prediction could suffer from large error accumulations and unable to achieve satisfactory performance. Therefore historical Sargassum distributions derived from MODIS are used to provide an alternative way to realize the bloom prediction. Chapter 5 proposes such a prediction based on a hindcast of 2000–2016 observations from MODIS, which shows Sargassum abundance in the CS and the CWA, as well as connectivity between the two regions with time lags (Appendix D). This information is used to derive bloom and nonbloom probability matrices for each 1° square in the CS for the months of May–August, predicted from bloom conditions in a hotspot region in the CWA in February. A suite of standard statistical measures is used to gauge the prediction accuracy, among which the user’s accuracy and kappa statistics show high fidelity of the probability maps in predicting both blooms and nonblooms in the eastern CS with several months of lead time, with an overall accuracy often exceeding 80%. The bloom probability maps from this hindcast analysis will provide early warnings to better study Sargassum blooms and prepare for beaching events near the study region. This approach may also be extendable to many other regions around the world that face similar challenges and opportunities of macroalgal blooms and beaching events. Using this forecasting scheme, the summer blooms in the CS in 2017 were successfully predicted. Since February 2018, we have also generated monthly-updated 1-page Sargassum outlook bulletins to help these regions to better prepare for potential beaching events. Currently, the mean Sargassum distribution statistics used in this study are derived from MODIS, which has been operating well beyond the designed mission life, arousing concerns as to whether the Sargassum observation statistics can be continued in the future. As a follow-on sensor, the Visible Infrared Imaging Radiometer Suite (VIIRS) has the appropriate spectral bands to detect and quantify floating macroalgae. Based on previous works on MODIS, Chapter 6 presents an improved procedure to extract floating algae pixels from VIIRS AFAI imagery, with image filtering used to suppress noise and adjusted thresholds used to mask sun glint, clouds, and cloud shadows. The overall extraction accuracy is about 85%. Simultaneous daily observations from MODIS and VIIRS over the CWA show consistent spatial patterns, but VIIRS estimations of the algae coverage (in km2) are consistently lower than MODIS (around – 19% mean relative difference or MRD), possibly due to lower sensitivity of the VIIRS near-infrared (NIR) bands than the corresponding MODIS bands. Similarly, at monthly scale VIIRS also shows lower coverage than MODIS, and their difference (around – 29% MRD) is larger than the difference between MODIS-Aqua and MODIS-Terra estimates (around – 14% MRD). Despite these differences, the spatial and temporal patterns between VIIRS and MODIS observed algae distributions match very well at all spatial and temporal scales. These results suggest that VIIRS can provide continuous and consistent observations of floating algae distributions and abundance from MODIS as long as their differences are accounted for, thus assuring continuity in the future. In summary, this study has worked on four connected topics regarding Sargassum distributions, biomass and nutrients, transport pathways, and bloom predictions through combined efforts in satellite remote sensing, field and laboratory measurements, physical modelling, and statistical analyses. To my best knowledge, this is the first comprehensive and multi-disciplinary study to investigate pelagic Sargassum at synoptic scale in the Intra-Americas Sea (IAS) and Atlantic Ocean. Although several questions remain to be answered (e.g., “What cause the inter-annual variations of Sargassum blooms?” and “Where are the bloom origins?”), the outcomes of this study (remote sensing algorithms, Sargassum distribution and abundance maps, established bio-physical model, and a bloom forecast model) are expected to make significant contributions in both scientific research (including new critical baseline data) and management decision support.

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White, Megan L. "ASSOCIATING SEVERE THUNDERSTORM WARNINGS WITH DEMOGRAPHIC AND LANDSCAPE VARIABLES: A GEOGRAPHICALLY WEIGHTED REGRESSION-BASED MAPPING OF FORECAST BIAS." UKnowledge, 2014. http://uknowledge.uky.edu/geography_etds/20.

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Severe thunderstorm warnings (SVTs) are released by meteorologists in the local forecast offices of the National Weather Service (NWS). These warnings are issued with the intent of alerting areas in the path of severe thunderstorms that human and property risk are elevated, and that appropriate precautionary measures should be taken. However, studies have shown that the spatial distribution of severe storm warnings demonstrates bias. Greater numbers of severe thunderstorm warnings sometimes are issued where population is denser. By contrast, less populated areas may be underwarned. To investigate the spatial patterns of these biases for the central and southeastern United States, geographically weighted regression was implemented on a set of demographic and land cover descriptors to ascertain their patterns of spatial association with counts of National Weather Service severe thunderstorm warnings. GWR was performed for each our independent variables (total population, median income, and percent impervious land cover) and for all three of these variables as a group. Global R2 values indicate that each individual variable as well as all three collectively explain approximately 60% of the geographical variation in severe thunderstorm warning counts. Local R2 increased in the vicinity of several urban regions, notably Atlanta, Washington, D.C., St. Louis, and Nashville. However, the independent variables did not exhibit the same spatial patterning of R2. Some cities had high local R2 for all variables. Other cities exhibited high local R2 for only one or two of these independent variables. Median income had the highest local R2 values overall. Standardized residuals confirmed significant differences among several NWS forecast offices in the number and pattern of severe thunderstorm warnings. Overall, approximately half of the influences on the distribution of severe thunderstorm warnings across the study area are related to underlying land cover and demographics. Future studies may find it productive to investigate the extent to which the spatial bias mapped in this study is an artifact of forecast culture, background thunderstorm regime, or a product of urban anthropogenic weather modification.

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Nassar, Ibrahim. "Long-Range, Passive Wireless Monitoring Using Energy-Efficient, Electrically-Small Sensor Nodes and Harmonic Radar Interrogator." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4923.

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This dissertation investigates the use of the harmonic radar technique for passive wireless sensing applications. Issues of DC power consumption, high RF activation power, large node size, and short communication range associated with the existing passive wireless sensing technologies are addressed by the development of novel, completely passive, high efficiency, compact 3-D harmonic sensor nodes. The node transceiver employs a passive frequency doubler to return the second harmonic of the interrogation signal, and electrically-small 3-D antennas to achieve the compactness and high efficiency. The developed nodes fit inside a sphere with a diameter < 3 cm and achieve communication range > 60 m using a 43 dBm EIRP interrogator. Effective modulation is demonstrated experimentally using low cost commercial vibration sensors. To address major challenges associated with long-range, embedded, passive wireless sensing including sensor node identification and remote channel calibration, a 3-D dual-channel transceiver is developed. To the best of the author's knowledge, the presented dual-channel transceiver is the first completely passive design with built-in passive remote channel calibration and identification capabilities, and the presented nodes have the best overall performance among previously published designs, in terms of conversion efficiency, communication range, and occupied volume. To reduce the cost and weight and improve the manufacturing process of the proposed nodes, the 3-D digital additive manufacturing and conformal direct printing technologies are employed. The harmonic interrogator antenna design is also an underlying focus of this work. Different interrogator antenna candidates are developed based on different design approaches. The first approach is based on the use of dual-channel antenna array, where one channel is used for transmission and the second channel is used for reception. Two dual-channel harmonic interrogator antennas that consist of 4-element circular patch antenna arrays and 2-element quasi-Yagi dipole antenna arrays are implemented. The second approach employs mechanically reconfigurable antennas to reduce the size and maintain persistent radiation properties over wide frequency bandwidth. Two mechanical reconfiguration methods are developed; the first method is based on the use of Hoberman's planar foldable linkage to vary the operating frequency of planar circular patch antennas and the second mechanical reconfiguration method is based on the use of a rack and pinion mechanism to reconfigure dual-band slot antennas. The third approach employs a single channel multi-octave Vivaldi antenna to provide the capability to interrogate a large number of harmonic tags that are widely spaced in frequency. To improve the antenna radiation performance over a broad frequency range, a new method based on the introduction of a parasitic elliptical patch in the flare aperture is proposed. This method enables gain and bandwidth improvement compared to what has been reported for Vivaldi antennas with a compact size. To provide the interrogator the capability to steer the radiation beam for locating and tracking sensor nodes, a topology to develop a miniature, non-dispersive switchable 4-bit phase shifter is proposed on the basis of composite right/left handed transmission line unit cells.

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Hamelius, Johan, and Per Enegren. "Vattennivåförändring kring Gamla Uppsala och dess påverkan på människan." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-177274.

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Gamla Uppsala är en plats som har haft stor betydelse för människan under en väldigt lång tid, både religiöst och kulturellt. Detta arbete syftar på att ta reda på vilka geologiska förutsättningar Gamla Uppsala hade för att kunna bli en så storslagen och viktig plats under så många år. Den senaste istiden, som lämnade kvar ett stort hav, gjorde att Gamla Uppsala inte kom ovanför vattenytan förrän ungefär 3000 år sedan. Arbetet beskriver hur landet steg upp ur havet, och hur människan för första gången tog sig dit, för att sedan börja använda marken, och skapa ett samhälle. För att få en mer komplett förståelse för hur samhället utvecklades religiöst och kulturellt har det studerats för att utreda varför Gamla Uppsala tappade sin status, och hur Gamla Uppsala storhetstid tog slut kring år 1200 e.Kr. Utöver detta har en modell tagits fram, för att kunna avläsa vattennivån vid en specifik tid. Med hjälp av denna modell har ett antal kartor tagits fram som visar den vattennivåändring som gav förutsättningar för kulturhistoriska utvecklingen.

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Svensson, Anna. "Modellering av supra och englaciala vattenkroppar detekterade i markradar data från Grönland." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-206118.

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Vår planet är under ständig omvandling, där de allt snabbare förändringarna i klimatet är mest påtagligt. Havsnivåförändringar vilket påverkar hela planeten, bestäms ur ett glaciologiskt perspektiv främst av hur mycket vatten som når haven vid smältning av stora mängder is. Smälter glaciärer kan vatten från ytan leta sig ned genom isen och nå botten under den, vilket kan leda till ökad hastighet hos glaciären genom smörjning av underlaget. Isdynamik är ett komplext område och vattnets väg genom isen och dess påverkan är dåligt känt. Det är därför betydelsefullt att få större kännedom om den fascinerande roll glaciärer spelar för vår planet. Vid tidigare markradarundersökningar på Grönland har reflektionsmönster i radardata upptäckts, vilka har gett upphov till spekulationer om vilken sorts vattenkropp som kan ha lett till det uppvisade mönstret. Då geofysiska metoder ofta kan leda till att olika vattenkroppar kan ge upphov till samma mönster, krävs ytterligare behandling av datat. Genom att använda en två-dimensionell, numerisk modell av fortplantingen av en elektromagnetisk puls genom ett medium, kan en teori om en viss vattenkropp uteslutas eller stödjas. Efter att modellen körts med både glaciärbrunnar och supraglaciala sjöar, framkommer det att sjöar ger ett tydligare VSH-mönster än brunnar, vilka tidigare antagits ha varit orsaken till nämnda VSH-mönster. Detta kan leda till ökad insikt om ytsmältvattnets väg genom isen, isars dynamik och dess påverkan på havsytenivån.

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Magnusson, Roger. "Transformationsmetoder : En fallstudie över ett detaljplanerat område i När socken." Thesis, Karlstads universitet, Institutionen för miljö- och livsvetenskaper (from 2013), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-83359.

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Region Gotland har påbörjat digitalisering av samhällsbyggnadsprocessen där kvalitetssäkring av digitala fastighetsgränser ingår. Rapporten tar upp teori, metod, resultat och analys av transformationsmetoder.En del av arbetet går ut på att ta fram lämpliga transformationsmetoder för ej återfunna gränsmarkeringar.Regionen har långa väntetider på bygglov. För att underlätta och minska handläggningstiden kommer de digitala detaljplanerna tolkas efter nymätta eller transformerade gränser. Digitala registerkartan som används i kartframställning har idag bristande kvalitet i form av felaktigt placerade gränser. I arbetsgruppen på regionen har beslut fattats att återfunna gränsmarkeringar inom detaljplanerade områden kommer att mätas och övriga kommer att transformeras med hjälp av data från förrättningsakter för att säkerställa att det digitala underlaget stämmer. Därefter kommer en webbapplikation skapas där fastighetsägare snabbt kan få svar på om den tänkta byggnationen är planenlig.Inmätning av fastighetsgränser utfördes med N-RTK-mätning samt fri totalstationsmätning som etablerades med GNSS-inmätta punkter.Koordinater för gränspunkter har tagits fram med transformationsmetoder där gränsmarkeringar inte har hittats exempelvis på grund av att stenmurar och vägar byggts över gränsmarkeringarna, gränsmarkeringar som inte längre har samma placering på grund av trädrötter som flyttat dem och gränsmarkeringar som placerats tillbaka felaktigt efter grävning vid avloppsbyte.Efter analysen av data konstateras att i detaljplanen 09-NÄR-366 är unitär transformation att föredra därför att skillnaderna i grundmedelfelen samt skalfaktorerna i transformationerna inte är stora samt att unitär transformation inte ändrar längder mellan gränsmarkeringarna och arealerna i fastigheterna.
Region Gotland has begun digitisation of the community building management, which include quality assurance of property boundaries. This report addresses theory, method, results and an analysis of the transformation methods.To require a building permit, the region has long waiting times. In order to facilitate and reduce the processing time, zoning plans will be interpreted according to their documents. Property boundaries within the zonings will be measured and transformed to improve quality and to verify the property boundaries.The measurements were performed with N-RTK measurement and setup of total station with GNSS-measured points.Coordinates for boundary markings have been updated with transformation methods where boundary markings have not been found. For example, where stone walls and roads have been built over the boundary markings, where boundary markings no longer have the same location due to tree roots moving them, or where boundary markings have been placed incorrectly after excavations.This report shows, that in this specific case, the difference between the transformation methods are small, therefore suggesting that the Unitary transformation is preferred because of the minor difference in distance and scale factors, and because Unitary transformation does not change lengths and areas.

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Pollock, Anna L. "Mid-Holocene Speleothem Climate Proxy Records from Florida and Belize." Scholar Commons, 2015. https://scholarcommons.usf.edu/etd/5548.

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As global temperatures rise due to anthropogenic climate change, water resources, thus economies, are threatened. A geologically recent period of increased temperatures is the mid-Holocene and an investigation of its climate may allow for a better understanding of future precipitation and changes to regional water resources. The regions of interest are tropical Northern Central America and subtropical North America with Belize and Florida representing each climate zone. By reconstructing mid-Holocene climate in Florida and Belize, I hope to provide a better understanding of how increased temperatures and a reduced latitudinal temperature gradient impacts both precipitation patterns and variability. Today, drivers of changes in precipitation include climate systems such as the Atlantic Multidecadal Variability (AMV), North Atlantic Oscillation (NAO), and the Intertropical Convergence Zone (ITCZ). Therefore, it is imperative to determine their latitudinal influences during the mid-Holocene and consequently their potential impact on water resources in the near future. Speleothems from Chen Ha Cave, Vaca Plateau, Belize and Brown's Cave, West Central Florida, provided high-resolution (sub-annual to decadal) oxygen and carbon stable isotope data that allowed for a detailed investigation of mid-Holocene climate. The speleothems were sampled along the growth axis of a cross-section for oxygen and carbon isotopic analysis. 234U-230Th dating was used to create a chronology for each record and determine the time step between each isotope sample. Time series analysis with variations of Fourier transforms, including Lomb-Scargle, wavelet analysis, and multi-taper method, was used to extract periodicities for each oxygen isotope record. To determine which atmospheric-oceanic modes influenced mid-Holocene precipitation, the speleothem periodicities were compared to those of known periodicities of atmospheric-oceanic modes, such as the AMV and NAO. Finally, the Florida and Belize records were assessed for coherency using cross wavelet analysis. The Floridian speleothem recorded less precipitation compared to present levels due to a westward expansion and intensification of the North Atlantic Subtropical High (NASH) with a quasi-persistent but less influential AMV. Relative to today, the mid-Holocene in Belize was slightly wetter which I suggest is a result of a more northerly ITCZ and an intensification of the NASH that increased the strength of the Caribbean Lower Level Jet (CLLJ). The Seuss solar cycle was also significant in Belize, contributing 7.2% of the precipitation variability. Wavelet coherency assessment reveal very little connectivity between the Florida and Belize speleothem reconstructions, potentially due to the blocking influence of the ITCZ. Comparison to other records from the mid-Holocene supports the hypothesis of an intensified NASH and more northerly ITCZ. A future increase in precipitation in Belize may lead to increased soil erosion, the need for crop adaptation, and risk to the population of low lying areas, such as Belize City. In Florida, reduced precipitation may result in a decrease in agricultural output and threats to the state's freshwater supply.

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48

Pirbudak, Ozan. "Reconstruction of Radar Images by Using Spherical Mean and Regular Radon Transforms." Scholar Commons, 2019. https://scholarcommons.usf.edu/etd/7889.

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The goal of this study is the recovery of functions and finite parametric distributions from their spherical means over spheres and designing a general formula or algorithm for the reconstruction of a function f via its spherical mean transform. The theoretical study is and supported with a numerical implementation based on radar data. In this study, we approach the reconstruction problem in two different way. The first one is to show how the reconstruction problem could be converted to a Prony-type system of equations. After solving this Prony-type system of equations, one can extract the parameters that describe the corresponding functions or distributions efficiently. The second way is to solve this problem via a backprojection procedure.

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Schultz, Maria. "KOMMUNAL PLANERING FÖR URBANA GRÖNOMRÅDEN." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-418544.

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During the last centuries, Sweden has become more urbanized and today 85% of the population are living in urban settlements. A future challenge for city planners is climate change, which is expected to lead to higher sea levels, rising temperatures, less snow and larger amounts of rainfall with more extreme precipitation. One approach for cities to deal with these challenges is to preserve urban greenspaces and the ecosystem services that they provide. For that reason, this essay aims to examine how municipalities are planning their urban green spaces and which motives are behind the planning for different ecosystem services. This was accomplished through a content analysis where three municipalities’ (Knivsta municipality, Uppsala municipality and Upplands Väsby municipality) planning and goal documents were examined. With the purpose to get knowledge about which ecosystem services were the most reoccurring. The results showed that the two most reoccurring ecosystem services in the three municipalities were recreation and biodiversity. The third most reoccurring ecosystem service in Uppsala municipality and Upplands Väsby municipality was water regulation, while in Knivsta municipality it was cultural heritage. The motives behind why the green spaces with these ecosystem services were seen as important were to prevent fragmentation of pathways and habitats important for biodiversity, and to ensure access to close and accessible greenspaces during urban infills and expansion. Furthermore, urban green spaces can be a part of the work for climate change adaption and for handling extreme precipitation.
Under de senaste århundrandena har Sverige urbaniserat och idag bor 85% av befolkningen i tätorter. En framtida utmaning för stadsplanerare är klimatförändringar vilka förväntas leda till höjd havsnivå, ökande temperaturer, mindre snö och ökad nederbörd med fler tillfälliga extrema nederbördsmängder. Ett sätt för städer att hantera dessa utmaningar är genom att bevara urbana grönområden och de ekosystemtjänster som de bidrar med. Av den anledningen syftar detta arbete att undersöka hur olika kommuner planerar för sina urbana grönområden och vilka motiv som finns bakom planerandet av olika ekosystemtjänster. Detta genomfördes genom en innehållsanalys på tre kommuners (Knivsta kommun, Uppsala kommun och Upplands Väsby kommun) planerings- och måldokument och då undersöktes vilka ekosystemtjänster som var mest återkommande. Resultatet visade att de två ekosystemtjänsterna som var mest återkommande i alla tre kommuner var rekreation och biologisk mångfald. Den tredje största ekosystemtjänsten var i Uppsala kommun och Upplands Väsby kommun reglering av vattenflöden medan den i Knivsta kommun var kulturarv. Motiven bakom varför grönområden med dessa ekosystemtjänster ansågs vara viktiga var för att hindra fragmentering av livsmiljöer och spridningsvägar viktiga för biologisk mångfald och för att se till att tillgången till nära och tillgängliga grönområden förstärks vid förtätning och tillväxt av staden. Dessutom är grönområden en viktig del inom städers klimatanpassningsarbete och för att förbereda städerna för en ökad mängd nederbörd.

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Denison, Francis. "SPECIATION DE L'URANIUM(VI), MODELISATION, INCERTITUDE ET IMPLICATION POUR LES MODELES DE BIODISPONIBILITE. APPLICATION A L'ACCUMULATION DANS LES BRANCHIES CHEZ UN BIVALVE D'EAU DOUCE." Phd thesis, Université de Provence - Aix-Marseille I, 2004. http://tel.archives-ouvertes.fr/tel-00009927.

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Les effets de différentes compositions de solution sur les interactions entre l'uranium(VI) et des branchies disséquées du bivalve d'eau douce Corbicula fluminea ont été étudiés dans des milieux de solution bien définis. Une réduction significative de l'accumulation de l'uranium a été observée en augmentant les concentrations de citrate et carbonates, ligands complexants de l'uranium. Des cinétiques de saturation en fonction de la concentration d'uranium ont été observées à pH 5,0, ce qui indique que l'accumulation d'uranium est un processus facilité, impliquant probablement un ou plusieurs systèmes de transport transmembranaire. Une modification relativement réduite de l'accumulation d'uranium a été constatée en fonction du pH (facteur de 2 environ), en dépit de modifications extrêmement importantes apportées à la spéciation en solution de l'uranium sur la plage de pH étudiée (5,0 – 7,5). Une revue exhaustive des données thermodynamiques relatives au domaine de composition de solution utilisé pour cette étude a été réalisée. Les estimations des incertitudes pour les constantes de formation des espèces aqueuses d'uranium(VI) ont été intégrées dans une base de données thermodynamiques. Un programme informatique a été élaboré afin de prévoir la distribution à l'équilibre de l'uranium(VI) dans les systèmes aqueux simples, à l'aide des valeurs moyennes des paramètres thermodynamiques. Le programme a été étendu afin de réaliser les analyses d'incertitude avec les méthodes de Monte Carlo et Quasi Monte Carlo, en intégrant les estimations des incertitudes de la base de données thermodynamiques, afin de prévoir de manière quantitative les incertitudes inhérentes à la prévision de la spéciation en solution de l'uranium. L'utilisation de la modélisation de l'équilibre thermodynamique en tant qu'outil d'interprétation de la biodisponibilité de l'uranium(VI) a été étudiée. Le comportement d'accumulation d'uranium(VI) observé a été interprété en fonction des modifications prédites de la spéciation en solution de l'uranium. Différentes approches d'état stationnaire ou de pré-équilibre pour la modélisation de l'accumulation d'uranium ont été testées. D'autres approches de modélisation ont également été testées, en prenant en considération les modifications potentielles de l'activité du système de transport membranaire ou des caractéristiques de sorption pour des compositions de solution variables. Enfin, l'effet de l'incertitude sur l'utilisation de la modélisation de l'équilibre thermodynamique pour interpréter la biodisponibilité de l'uranium (VI), a été évalué.

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Dissertations / Theses on the topic 'Other Earth Sciences'

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