Dissertationen: „Sea monitoring“

1

Turner, Andrew. „Chemical dynamics in North Sea estuaries and plumes“. Thesis, University of Plymouth, 1990. http://hdl.handle.net/10026.1/1684.

Der volle Inhalt der Quelle

Annotation:

Observational and experimental studies have been undertaken in the southern North Sea environment, including five major estuaries (Humber, Thames, Scheldt, Weser and Elbe), with the aim of elucidating the mechanistic and kinetic details of trace metal reactivity required for the refinement of pollutant transport models. The results of a systematic investigation of suspended particle characteristics (BET specific surface area and porosity, carbon content. Fe and Mn oxide coatings) indicated that, although there exists significant yet explicable variability among the North Sea estuaries, such compositional factors do not exert an observable influence on solid-solution interactions. Furthermore, chemical reactivity was not usually demonstrable from observations of leachable particulate trace metals as phase interactions Impart relatively little influence on their concentrations; particulate metal distributions therefore generally conformed with mixing of fluvial and marine material unless perturbed by major anthropogenic sources as in the Humber. Solid-solution redistributions were revealed by following the partitioning of artificial radiotracers in a series of carefully controlled experiments in which salinity and suspended solids concentration gradients were simulated by mixing river and sea water end-member samples. Relationships between salinity and the solid:solution concentration of radiotracers as quantified by a distribution coefficient ( K Q ) indicated substantial desorption from particles of ^^®Cd and ^"^^Cs. conservative behaviour of ^ ^ Z n , and oxidative removal from solution of ^^Mn. Radiochemical techniques applied in situ to study solid-solution partitioning in the southern North Sea established a more significant role of particle composition (in particular, estuarine-derived versus plankton-rich material) in regulating trace metal behaviour in offshore waters. This finding was corroborated by distinct seasonal contrasts in measured particulate metal concentrations; whereas most metals (Fe, Mn. Cu, Pb, Zn) were enriched during winter when detrital and terrigenous components from fluvial/resuspension inputs dominate. Cd was elevated during summer in tandem with amplification of the biomass. These results provide a valuable basis for both future long-term pollutant monitoring programmes, and the conceptual development of estuarine chemical flux models, specifically the incipient Plymouth Marine Laboratory model of the Humber plume.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

2

Jones, Kate. „Monitoring, Assessment, and Management of the Green Sea Urchin (Strongylocentrotus droebachiensis) Fishery in Maine“. Fogler Library, University of Maine, 2006. http://www.library.umaine.edu/theses/pdf/JonesKX2006.pdf.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

3

Sun, Yiping. „Sea state monitoring by radar altimeter from a microsatellite“. Thesis, University of Surrey, 2001. http://epubs.surrey.ac.uk/844478/.

Der volle Inhalt der Quelle

Annotation:

This thesis constitutes a general survey and a study of significant extensions to the usual conventional satellite radar altimetry. Historically radar altimeter has been configured to the measurement of mean sea level. It is well known that other statistics such as Significant Wave Height (SWH) and wind speed are in principle recoverable from the radar echo and these are currently of great interest. It has been the aim in this thesis to optimize such measurements, for a general meteorological application, with less interest shown in absolute measurement of sea level. Current technology makes possible a total Earth survey using a constellation of small satellites, covering the entire Earth sea surface with short revisit time. Such solutions necessitate less cost, lower power, and less precise attitude control than the scientific satellites used hitherto. The purpose of this thesis is to present a novel two mode radar altimeter for sea state monitoring. SWH is still measured by conventional high-resolution mode, which is not sensitive to off-nadir pointing. An additional novel low-resolution mode is proposed for wind speed measurement. By using this mode, wind speed measurement is much more robust to pointing error than by using conventional high-resolution mode. An improved wind speed measurement can be achieved by using a cost effective small satellite. Some considerable time was also spent on incorporating SAR (Synthetic Aperture Radar) into altimetry techniques to improve the signal to noise ratio. For sea state monitoring the improvements are relatively disappointing, although greater improvement are expected for ice sheet monitoring.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

4

Zheng, Yuanxing. „Microsatellite radar altimeter payload design for global sea state monitoring“. Thesis, University of Surrey, 2000. http://epubs.surrey.ac.uk/843200/.

Der volle Inhalt der Quelle

Annotation:

A detailed understanding of the relationship between altimetry measurement, especially significant wave height (SWH) measurement, and phase distortion is still unclear. Therefore, the objective of this Ph.D. study is first to outline this relationship by a simulation using a model that considers the errors from both the signal source and the power amplifier. The simulation results show the power amplifier influence is more significant than that of signal source in SWH estimation, and that the phase errors influence is worse for lower SWH conditions. It is recommended from the simulation that the group delay error of the whole transmitter link, after the chirp generator, should be well controlled to be under 0.5ns. In the payload design, Class-F is chosen as the amplifier operation mode due to its high efficiency and fewer harmonic frequency components. The difference between the operational principles of second and third harmonic peaking Class-F amplifiers have been illustrated by the simulation. Both of them can achieve high efficiency and high gain, however the third harmonic peaking Class-F is simpler to implement. Therefore it was chosen by the final design. In the simulation, a large signal STATZ model is set up, followed by the S-band Class-F amplifier design simulation and the implementation of third harmonic peaking Class-F amplifier. Based on this, an adaptive feedback group delay equalizer is proposed as a solution for the phase error compensation within the whole chirp signal swept bandwidth. A very simple but effective phase error detection and calculation circuit is designed, built and measured. The test branch results are very satisfying. Its small size and lower power consumption makes it very suitable for a compact microsatellite environment. In summary, the possibility of a medium resolution microsatellite borne radar altimeter for optimising shipping routes is investigated in this study. A 12 satellites constellation is proposed for achieving near real time altimetry broadcasting. The key payload design problems are identified in a thorough feasibility study: the restriction corresponding to these main problems is quantified via the SWH estimation simulation. A feedback linearization method is proposed as a promising solution for the compact microsatellite design with high power efficiency requirements, demonstrated by both simulation and hardware implementation results.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

5

Bian, Ka. „Space-borne application of GNSS reflectometry for global sea state monitoring“. Thesis, University of Surrey, 2007. http://epubs.surrey.ac.uk/2221/.

Der volle Inhalt der Quelle

Annotation:

This research focuses on modelling the relationship between wind conditions, sea roughness and GNSS reflections received from Low Earth Orbit (LEO). The motivation for this study lies in the recent development of a GNSS reflections receiver platform for the UK-DMC satellite and the numerous advantages proposed GNSS Reflectometry can provide in Earth Observation and global disaster monitoring. The fIrst part of the thesis focuses on the simulation procedure of received GPS-R Delay-Doppler Map (DDM). Airborne GPS-R scatterometric model has been adapted into this space-borne application research. Aft~r deriving DDM simulations according to reflection scenario, the results of two-dimensional data-model fItting are presented and analysed. The sensitivity discussion of current GPS-R model suggests some limitations of the modelling method, especially under medium and high wind speed ranges. In the second part, we investigate the inversion scheme of DDMs for the purpose of extracting a statistical wave model empirically. The similar model structure of DDM simulation is used but the processing order is turned over. After deconvolution, DDMs are inversed back to spatial energy maps and spatial slope probability maps. Three inversion algorithms are developed and compared. Preliminary synthetic and real data experiments give evidence of the feasibility of the inversion methodology. Finally, in the third part of this research, a new geometric wave slope statistical model is discussed in the context of wave fIeld simulations. The sensitivity of obtained statistical model is discussed in terms of wind speed, wave direction and observing incident angle. This provides an alternative view point to look into the wave slope probability properties and compensate the traditional theoretic and empirical wave modelling methods. Key words: GNSS-Reflectometry, Delay-Doppler Map inversion, wind conditions, sea surface roughness, slope probability density function, statistical wave slope model.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

6

Brooke, Samuel T. „Diver selection and performance monitoring for deep (#>#300 msw) working dives“. Thesis, Cardiff University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253558.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

7

Chang, Chia-Chyang. „Monitoring of tide gauge heights in Western Europe by GPS“. Thesis, University of Nottingham, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294704.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

8

Jonasson, Sara. „Monitoring the cellular phosphate status in bloom-forming cyanobacteria of the Baltic Sea /“. Stockholm : Department of Botany, Stockholm university, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-1302.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

9

David, Anthony R. J. „Flow injection instrumentation for the in situ monitoring of nutrients in sea water“. Thesis, University of Plymouth, 1996. http://hdl.handle.net/10026.1/1690.

Der volle Inhalt der Quelle

Annotation:

In order to investigate the biogeochemistry of aquatic ecosystems, a quantitative understanding of primary production and the temporal and spatial distribution of nutrients is necessary. This thesis describes the development of a submersible FI based nutrient sensor for the in situ determination of nitrate in estuarine and coastal waters. Chapter One describes the role of nitrogen in the global and marine nitrogen cycles and provides an overview of laboratory and in situ methods for its determination. Chapter Two describes the key parameters for a field instrument and culminates with the overall design specification for the system. Chapter Three describes in detail the design, build and optimisation of the key individual components of the system, e.g. sample delivery system, injection valve, reduction column, reaction column, flowcell, on-board control system and the housing of the complete integrated system. Chapter Four describes the optimisation and analytical performance of the FI instalment prior to field trials. The key operational parameters such as flowcell path length, injection volume and detector response were investigated. LOD, reproducibility and linear range were determined and the control programme for the onboard computer is reported. For example, a LOD of 0.01 Nitrate-N, a linear range of 0-140 | iM Nitrate-N and a reproducibility of ± 5 % were achieved. Chapter Five describes the field experiments where the FI system was initially used as a bench instrument and compared to a laboratory FI method which had been validated by participation in two interlaboratory exercises and for nitrate in river and sea water. The first submersed deployments involved the optimisation of the system operational characteristics and developing the field techniques. The final part of this chapter describes the weekly field studies of Barn Pool in Plymouth Sound using the submersed nutrient sensor for a period of two months. The operation and performance of the submersed sensor was assessed against an air segmented continuous flow analyser during a Land Ocean Interaction Study (LOIS) North Sea cruise aboard the RVS Challenger. The results from this exercise and the relevant salinity and turbidity measurements are presented in Chapter Six.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

10

McCormack, Trevor. „Flow injection chemistries for the in situ monitoring of nutrients in sea water“. Thesis, University of Plymouth, 1996. http://hdl.handle.net/10026.1/494.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

11

Sanli, Dogan Ugur. „GPS strategies for tide gauge monitoring with assessment of sea level analysis models“. Thesis, University of Newcastle Upon Tyne, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285534.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

12

Harvey, Therese. „Bio-optics, satellite remote sensing and Baltic Sea ecosystems : Applications for monitoring and management“. Doctoral thesis, Stockholms universitet, Institutionen för ekologi, miljö och botanik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-119578.

Der volle Inhalt der Quelle

Annotation:

Earth observation satellites cover large areas with frequent temporal repetition and provide us with new insight into ocean and coastal processes. Ocean colour measurements from satellite remote sensing are linked to the bio-optics, which refers to the light interactions with living organisms and dissolved and suspended constituents in the aquatic environment. Human pressures have changed the aquatic ecosystems, by, for example, the increased input of nutrient and organic matter leading to eutrophication. This thesis aims to study and develop the link between bio-optical data and the remote sensing method to the monitoring and management of the Baltic Sea. The results are applied to the European Union’s Water Directives, and the Baltic Sea Action Plan from the Helsinki commission. In paper I indicators for eutrophication, chlorophyll-a concentration and Secchi depth were evaluated as a link to remote sensing observations. Chlorophyll-a measurements from an operational satellite service (paper I) were compared to conventional ship-based monitoring in paper II and showed high correlations to the in situ data. The results in paper I, II and IV show that the use of remote sensing can improve both the spatial and temporal monitoring of water quality. The number of observations increased when also using satellite data, thus facilitating the assessment of the ecological and environmental status within the European Union’s water directives. The spatial patterns make it possible to study the changes of e.g. algae blooms and terrestrial input on larger scales. Furthermore, the water quality products from satellites can offer a more holistic and easily accessible view of the information to decision makers and end-users. In paper III variable relationships between in situ bio-optical parameters, such as coloured dissolved organic matter (CDOM), dissolved organic carbon, salinity and Secchi depth, were found in different parts of the Baltic Sea. In paper IV an in situ empirical model to retrieve suspended particulate matter (SPM) from turbidity was developed and applied to remote sensing data. The use of Secchi depth as an indicator for eutrophication linked to the concentrations of chlorophyll-a and SPM and CDOM absorption was investigated in paper V. The variations in Secchi depth were affected differently by the mentioned parameters in the different regions. Therefore, one must also consider those when evaluating changes in Secchi depth and for setting target levels for water bodies. This thesis shows good examples on the benefits of incorporating bio-optical and remote sensing data to a higher extent within monitoring and management of the Baltic Sea.

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Manuscript. Paper 5: Manuscript.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

13

Adams, Susanne [Verfasser], und Günther [Akademischer Betreuer] Heinemann. „Monitoring of thin sea ice within polynyas using MODIS data / Susanne Adams ; Betreuer: Günther Heinemann“. Trier : Universität Trier, 2012. http://d-nb.info/1197806350/34.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

14

Durland, Donahou Allison. „Loggerhead Sea Turtle (Caretta caretta) Hatchling Disorientation in Broward County, Florida“. NSUWorks, 2014. http://nsuworks.nova.edu/occ_stuetd/15.

Der volle Inhalt der Quelle

Annotation:

Hatchling disorientation after emergence is a major factor impacting sea turtle populations. This study utilized data from over 1,200 Florida Fish and Wildlife Conservation Commission (FWC) Marine Turtle Disorientation Report forms from years 2006 to 2011 to assess changes in the severity and locations of disorientation events and the impact of municipal beach lighting ordinances. While the FWC forms were completed for all sea turtle species observed, this study focused only on loggerhead sea turtles (Caretta caretta). A Disorientation Severity Index (DSI) was derived from the number of hatchlings and the direction of their tracks leaving the nests to evaluate the changes in disorientation over six years in Broward County. The FWC forms provide a much larger database for the analysis of hatchling disorientation patterns and trends than can be derived from the more precise, but labor intensive, Hatchling Orientation Index (HOI) survey method of Witherington et al. (1996). This research differs from prior work by focusing on the information provided in the FWC Marine Turtle Disorientation Report forms; using each individual disorientation to assess changes in the severity of hatchling disorientations over time. Prior work has not used the FWC forms for analysis. Significant differences were found for average DSI between years and locations. Overall, DSI decreased significantly from 2006 to 2011 in Hillsboro Beach, Pompano Beach, Lauderdale-by-the-Sea, Fort Lauderdale, and Hollywood. This might be due to increased compliance with lighting ordinances. In addition, disorientation hotspots were identified and the DSI in these hotspots decreased significantly in central and south Fort Lauderdale, Pompano Beach, and Lauderdale-by-the-Sea. Hotspots were visually identified as R-Zone ranges with higher numbers of disorientations than in other ranges (Fig. 6). Artificial beach illumination is very prevalent in Broward County. However, there was no significant relationship between the number of types of lights that were recorded on the FWC forms and DSI. Disorientations seemed to be clustered within hotspots with known lighting issues. Management strategies should use these analyses to reassess loggerhead recovery plans to reduce disorientation hotspots and increase hatchling recruitment.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

15

Joodaki, Saba. „Application of the Reflection SeismicMethod in Monitoring CO2 Injection in aDeep Saline Aquifer in the Baltic Sea“. Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-200179.

Der volle Inhalt der Quelle

Annotation:

Time-lapse reflection seismic methods have proven effective fordetecting and monitoring the injection and spreading of geologicallystored CO2. These methods are based on interpreting changes in themedia’s elastic properties that result from replacing the native salinewater by the injected CO2, which in turn affects the seismic velocitiesof the media. Since applications of these methods in the field areexpensive, and the interpretation process is time consuming, pre-studyinvestigations should be done in order to determine whether or notreflection seismic surveys can successfully be applied to monitor theCO2 plume in the case of interest.In the present study, CO2 injection and migration in a deep salineaquifer based on a structure situated below the south-western part ofthe Baltic Sea was modeled. To determine the CO2 saturationdistributions at different times, the injection was numericallysimulated using TOUGH2/ECO2N. A radial-symmetric model withhomogeneous and isotropic properties was assumed and two differentinjection rates were studied, with the results analyzed at differenttimes after the start of the injection.The saturation and density values resulting from the TOUGH2simulation were converted to seismic velocities using the Biot-Gassmann model. A synthetic velocity model was built based on bothTOUGH2 and Biot-Gassmann models and synthetic seismic responsefields before and after injection were generated. The results show thatthe amplitude changes in the seismic response are detectable even forsmall amounts of injected CO2, while noticeable signs of velocitypushdown, as a signature of the CO2 substitution, could only beobserved if the injection rate is high enough.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

16

Pensa, Francesco <1981&gt. „Marine biodiversity survey in the Northern Red Sea: a large-scale monitoring carried out in collaboration with volunteer divers“. Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5832/.

Der volle Inhalt der Quelle

Annotation:

Concerns over global change and its effect on coral reef survivorship have highlighted the need for long-term datasets and proxy records, to interpret environmental trends and inform policymakers. Citizen science programs have showed to be a valid method for collecting data, reducing financial and time costs for institutions. This study is based on the elaboration of data collected by recreational divers and its main purpose is to evaluate changes in the state of coral reef biodiversity in the Red Sea over a long term period and validate the volunteer-based monitoring method. Volunteers recreational divers completed a questionnaire after each dive, recording the presence of 72 animal taxa and negative reef conditions. Comparisons were made between records from volunteers and independent records from a marine biologist who performed the same dive at the same time. A total of 500 volunteers were tested in 78 validation trials. Relative values of accuracy, reliability and similarity seem to be comparable to those performed by volunteer divers on precise transects in other projects, or in community-based terrestrial monitoring. 9301 recreational divers participated in the monitoring program, completing 23,059 survey questionnaires in a 5-year period. The volunteer-sightings-based index showed significant differences between the geographical areas. The area of Hurghada is distinguished by a medium-low biodiversity index, heavily damaged by a not controlled anthropic exploitation. Coral reefs along the Ras Mohammed National Park at Sharm el Sheikh, conversely showed high biodiversity index. The detected pattern seems to be correlated with the conservation measures adopted. In our experience and that of other research institutes, citizen science can integrate conventional methods and significantly reduce costs and time. Involving recreational divers we were able to build a large data set, covering a wide geographic area. The main limitation remains the difficulty of obtaining an homogeneous spatial sampling distribution.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

17

Ghadhban, Zaid T. „Design of a stand alone fully integrated communications, monitoring and control system for a novel remote sub-sea gas facility“. Curtin University of Technology, Faculty of Engineering, Department of Chemical Engineering, 2008. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=120520.

Der volle Inhalt der Quelle

Annotation:

The growing demand for hydrocarbon fluids, and the future expectation of insufficient onshore reserves, is driving the exploration and development of off-shore oil and gas fields. A significantly increasing number of the new fields are situated in deep water, placing significant constraints on the application of conventional platform (sea surface) systems. This has, by necessity, generated the rapid growth of sub-sea processing technology.
An integral part of a novel sub-sea natural gas dehydration project is the need to design and develop a communications, monitor and control system that is extremely reliable within a harsh marine environment. The off shore gas gathering and processing facility will be unmanned, therefore the entire ongoing operation of the sub-sea facility, and any sea surface equipment, will be dependent on the proper functioning of the communication system. System redundancy and low power consumption are also important issues.
The continuous bi-directional transmission of information between the field and shore-based control centres, together with the complexity of any maintenance / repair missions requires an extremely highly reliable system. The prospect of false alarms must be maintained at an absolute minimum.
Within this thesis the history and development of ocean based communications up to current state-of-the art technology is reviewed. Based on the unique and demanding requirements of the sub-sea gas processing facility, detailed recommendations are made for both a primary and back-up communication systems that meet the given criteria of being robust and having very low power requirements.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

18

Schmidt, Verena. „Parasites of European flounder (Platichthys flesus L.) from the German Bight, North Sea, and their potential use in ecosystem monitoring“. [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=969686501.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

19

Pasquini, Giulia. „Assessment of marine litter in the Western Adriatic Sea and its impact on marine biota“. Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10043/.

Der volle Inhalt der Quelle

Annotation:

Due to its environmental, safety, health and socio-economic impacts, marine litter has been recognized as a 21st century global challenge, so that it has been included in Descriptor 10 of the EU MSFD. For its morphological features and anthropogenic pressures, the Adriatic Sea is very sensitive to the accumulation of debris, but data are inconsistent and fragmented. This thesis, in the framework of DeFishGear project, intents to assess marine litter on beaches and on seafloor in the Western Adriatic sea, and test if debris ingestion by fish occurs. Three beaches were sampled during two surveys in 2015. Benthic litter monitoring was carried out in the FAO GSA17 during fall 2014, using a rapido trawl. Litter ingestion was investigated through gut contents analysis of 260 fish belonging to 8 commercial species collected in Western Gulf of Venice. Average litter density on beaches was 1.5 items/m2 during spring, and decreased to 0.8 items/m2 in summer. Litter composition was heterogeneous and varied among sites, even if no significant differences were found. Most of debris consisted of plastic sheets, fragments, polystyrene pieces, mussels nets and cottons bud sticks, showing that sources are many and include aquaculture, land-based activities and local users of beaches. Average density of benthic litter was 913 items/Km2 (82 Kg/Km2). Plastic dominated in terms of numbers and weight, and consisted mainly of bags, sheets and mussel nets. The highest density was found close to the coast, and sources driving the major differences in litter distribution were mussel farms and shipping lanes. Litter ingestion occurred in 47% of examined fish, mainly consisting of fibers. Among species, S. pilchardus swallowed almost all debris categories. Findinds may provide a baseline to set the necessary measures to manage and minimize marine litter in the Western Adriatic region and to protect aquatic life from plastic pollution, even accounting the possible implications on human health.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

20

Jelley, Neil. „Forecasting seasonal drawdowns in Whangamata town supply wells“. The University of Waikato, 2007. http://hdl.handle.net/10289/2234.

Der volle Inhalt der Quelle

Annotation:

The coastal township of Whangamata's reticulated water supply is provided by a number of groundwater bores, extracting water from local fractured rhyolite and andesite aquifers. A need has arisen to create a greater understanding of the aquifers, because of an increased demand for water abstraction. Water demand in Whangamata increases dramatically during the summer vacation period. Occupant numbers increase from 4,000 up to 50,000 during peak times, resulting in increased water demand. Over the past five years an increase in groundwater abstraction has produced an evident downward trend in bore water levels. Electrical conductivity is also increasing in several aquifers, posing a realistic threat of sea water intrusion and questioning the sustainability of current abstraction volumes. Multiple linear regression and an artificial neural network model were investigated as simple empirical forecasting tools for well drawdowns to predict the effect of future increases in groundwater demand. This approach was adopted as opposed to a groundwater numerical model because of poor time resolution of available data and the complex, fractured nature of the aquifer. By using pumping volumes as variables, seasonal bore water level variations and long term trends were predicted. The models were evaluated with independent validation data sets. The actual ability of a model to predict bore water level seasonal variation and long term trends was assessed using a comparison with a moving average of the validation data set. Multiple linear regression proved superior to the neural network in almost every bore modelled. Although neural networks proved capable of modelling seasonal bore water level variations it was not to the same degree of accuracy as the regression approach. The regression approach yielded a modified index of agreement of 0.6-0.74 when comparing a moving average of observed data with the validation data sets. The developed models were used to forecast well water levels with varying abstraction volumes aiming to prevent further long term decline in bore water levels.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

21

Ellis, Joanne I. „Incorporation of spatial gradients into benthic impact assessment“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0009/NQ34715.pdf.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

22

Hansson, Tomas. „Biomarkers in perch (Perca fluviatilis) used in environmental monitoring of the Stockholm recipient and background areas in the Baltic Sea“. Doctoral thesis, Stockholms universitet, Institutionen för tillämpad miljövetenskap (ITM), 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-8143.

Der volle Inhalt der Quelle

Annotation:

This thesis reports the results of biomarker measurements in three environmental monitoring projects. In the first project, which was part of the Swedish national environmental monitoring, biomarkers were measured annually in female perch (Perca fluviatilis) in two background areas in the Baltic Sea during 1988–2000, resulting in a unique 13-year series of measurements. The most important results were a strong decreasing temporal trend in the gonadosomatic index (GSI) and a strong increasing temporal trend in the hepatic ethoxyresorufin O-deethylase (EROD) activity in the Baltic Proper. In the second project, biomarkers and concentrations of classic pollutants were measured in female perch in the Stockholm recipient 1999–2001. This was the first time a large city was investigated as a point source of pollution, and the gradient was longer and included more stations than customary. Severe pollution conditions in central Stockholm were indicated by the poor health status of the perch: retarded growth, decreased frequency of sexually mature females, low GSI, disturbed visceral fat metabolism, increased hepatic EROD activity, decreased muscle acetylcholinesterase activity, increased frequency of hepatic DNA adducts, and a high concentration of biliary 1-pyrenol. Muscle ΣDDT and ΣPCB were measured as pollution indicators and were 10–28 respectively 12–35 times higher than the background levels in perch from the Baltic Proper. In the Stockholm archipelago two superimposed gradients were found. Whereas the response of several biomarkers consistently decreased with increasing distance from central Stockholm, the response of others first decreased from Stockholm to the middle archipelago and then increased to the open Baltic Sea. The latter biomarkers included the frequency of sexually mature females, GSI, hepatic EROD activity, and hepatic DNA adducts. In the third project, potential toxicity from munitions on the seafloor, at a dumpsite in the Stockholm archipelago, was analysed by the nanoinjection of sediment extracts into newly fertilised rainbow trout (Oncorhynchus mykiss) eggs, followed by the measurement of biomarkers in the developing larvae. No biological effects of the dumped munitions were found. The same stations in the Stockholm archipelago as in the second project were investigated as a positive control. The results of the three projects agreed well, which demonstrated the continuous pollution of the Baltic Sea and the severe pollution conditions and adverse biological effects in central Stockholm. Further investigations are urgently needed to identify which pollutants or other factors are causing the observed biological effects, both in the background areas in the Baltic Sea and in the Stockholm recipient.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

23

Merlo, Vittoria. „Abundance and composition of marine litter along the italian coasts: contribution from official monitoring and citizen science“. Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020.

Den vollen Inhalt der Quelle finden

Annotation:

Assessment of amounts, distribution, composition and sources of beach litter was conducted on Italian coast in 2017. Data have been collected by scientific staff from the Regional Environmental Protection Agencies of Italy (MSFD), and by citizen scientists coordinated by the environmental association Legambiente (Clean Up the Med initiative). The vast majority of marine litter collected (>70%) were plastic objects, 30% of which were single-use plastic. In the investigated MSFD subregions, Adriatic Sea appeared to have the highest presence of fishing-related items (7.76%), Western Mediterranean Sea had a high number of cigarette butts and filters (8.19%) and Ionian and Central Mediterranean Sea had plastic bags (8%). Considering the level of urbanisation, rural beaches are the only one that showed a low abundance of Smoke-related litter (min-max: 0-21 items/100 m - <4%), urban beach resulted in having cigarette butts and filters (min-max: 6-140 items/100 m - 9.22%). “Non-sourced” items represented a large percentage of the litter found in all subregions and among beach type (29%-50%), together with “Public litter” (31% to 53%). Coastal Clean Index (CCI), used for testing the beach cleanliness, showed that most beaches were classified as Very Clean or Clean in both study periods investigated in the framework of the MSFD. Comparison between the MSFD monitoring and the Clean Up the Med initiative showed that there were no significant differences in the total density of beach litter detected, but there was a significant difference in terms of composition. This was probably due to the fact that Clean Up The Med survey was unbalanced between regions, due to the voluntary nature of the project. The results remarked how urgent is a national action against beach littering (plastic in particular), and the need in a global shift in human mindsets and behaviour, that could happen also thank to the work of citizen science volunteers and environmental association as Legambiente.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

24

Garnaga, Galina. „Integruotas aplinkos taršos bei biožymenų atsako vertinimas Baltijos jūroje“. Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110502_093337-29293.

Der volle Inhalt der Quelle

Annotation:

Disertacijos tikslas – integruotas teršalų pasklidimo aplinkoje ir jų biologinio poveikio Baltijos jūros Lietuvos zonoje vertinimas. Darbe buvo apibendrinti ilgalaikių aplinkos taršos tyrimų Baltijos jūros Lietuvos zonoje duomenys, aprašyti teršalų pasklidimo ypatumai Klaipėdos uosto, grunto gramzdinimo jūroje, Būtingės naftos terminalo, D-6 naftos platformos ir cheminio ginklo nuskandinimo rajonuose, tirti aplinkos taršos biožymenų jūrų organizmuose iš skirtingų pietrytinės Baltijos jūros rajonų ypatumai bei atliktas eksperimentas sąryšio tarp teršalų ir biožymenų atsako moliuskų audiniuose ypatumams nustatyti. Darbas atitinka HELCOM Baltijos jūros veiksmų plano ir ES Jūrų strategijos pagrindų direktyvos iškeltus tikslus – „Baltijos jūros aplinka nepaveikta pavojingų medžiagų“ ir „teršalų koncentracijos lygis yra toks, kad nesukelia taršos poveikio“. Norint pasiekti šiuos tikslus, būtina atlikti kompleksinį Baltijos jūros aplinkos būklės vertinimą. Šiems tikslams sukurtas HELCOM Cheminės būklės vertinimo įrankis CHASE (angl. Chemical Status Assessment Tool), buvo panaudotas kompleksiškai vertinant Lietuvos Baltijos jūros rajonų aplinkos taršą. Atsiranda vis daugiau moksliniais tyrimais pagristų įrodymų, kad biologinių efektų tyrimai yra svarbūs. Šis darbas yra dar vienas biologinių efektų tyrimų svarbos įrodymas ir tokio pobūdžio tyrimų įtraukimo į valstybinės stebėsenos programą aktualumo patvirtinimas.
The aim of the study is an integrated assessment of the spread of contaminants and their biological effects in the Lithuanian zone of the Baltic Sea. Long-term monitoring data on contaminants in water, sediments and biota were summarized; the peculiarities of distribution of contaminants in the Klaipėda harbour, Būtingė oil terminal, dredged sediments dumping site, adjacent area to the Russian D-6 oil platform and chemical munitions dumpsite were described; biomarker responses in marine organisms from the different areas of the southeastern Baltic Sea and the Curonian Lagoon were evaluated and the impact of contaminants on biomarker responses in mussels was assessed. The thesis reflects the overall goals of the hazardous substances segment of the HELCOM Baltic Sea Action Plan – to achieve a Baltic Sea with life undisturbed by hazardous substances and of the EU Marine Strategy Framework Directive – concentrations of contaminants are at levels not giving rise to pollution effects. The ongoing activities of HELCOM and EU are aimed at the integrated holistic assessments of the environmental state of the Baltic Sea. The combination of contaminant concentrations with the biological effects were used in the HELCOM Chemical Status Assessment Tool CHASE, which also has been applied for Lithuanian waters. Whereas more scientific evidences appear the biological effects become an important issue of the environmental research. This study also reflects the importance of integration of... [to full text]

APA, Harvard, Vancouver, ISO und andere Zitierweisen

25

Doya, Le Besnerais Carolina. „The use of new multiparametric observatory platforms for the remote monitoring and exploration of deep-sea ecosystems at day-night and seasonal temporal scales“. Doctoral thesis, Universitat Politècnica de Catalunya, 2017. http://hdl.handle.net/10803/457573.

Der volle Inhalt der Quelle

Annotation:

Traditional sampling technologies such as trawling but also novel ones as ROV surveying are oriented toward a high spatial coverage without repeating data collection at fixed seabed windows. The temporal repetition is often neglected so any reported difference in sampling among sites or studies may potentially be confounded with time-induced variations as a product of rhythmic population displacements within the continental margin seabed and water column 3D scenarios. Behaviour is an important life trait conditioning our perception of deep-sea biodiversity, being its rhythmic expression upon different diel (i.e. 24-h based day-night and tidal cycles) poorly known. In this context, technological step forward must be taken in order to observe community changes in deep-sea areas as a product of population behavioural patterns. Here, I studied how activity rhythms of benthic species within deep-sea communities modulate their composition, species abundances, richness, biodiversity and other life-history trait information in representative deep-sea environments through the use of multiparametric video-fixed cabled and non-cabled stations plus moving platforms. At the same time, I provided new methodological sampling hints on data collection protocols and analyses specifically tuned to the different characteristic of each observatory platform. I shed new light on the regulation that environmental cycles exert on animals' rhythmic behavior, revealing that the main environmental rulers affecting deep-sea benthic communities are still day-night indirect or more direct tidal-oriented cycles which act on endobenthic, benthopelagic, and nektobenthic migrations.
Las tecnologías de muestreo tradicionales, como la pesca de arrastre, pero también las nuevas, como los trabajos con ROV, están orientadas hacia una elevada cobertura espacial sin necesariamente repetir la recopilación de datos en ventanas fijas de los fondos marinos. Esa repetición temporal es a menudo obviada por lo que cualquier diferencia en el muestreo entre sitios o estudios puede quedar enmascarada por las variaciones a escala temporal como resultado de los desplazamientos rítmicos de la población dentro del margen continental marino y el volumen tridimensional de columna de agua. El comportamiento en los animales es un rasgo importante que condiciona nuestra percepción de la diversidad biológica de los fondos marinos, siendo su expresión rítmica diaria (es decir, ciclos día-noche y mareales) mal conocida. En este contexto, hay una necesidad de avance tecnológico y metodológico que permita la observación de las variaciones en las comunidades del mar profundo en las zonas de aguas profundas como producto de los patrones de comportamiento poblacional. Aquí estudié cómo los ritmos comportamentales de las especies bentónicas y bentopelágicas modulan composición, abundancia de especies, riqueza, diversidad biológica y otra información del ciclo biológico de dichas especies y comunidades dentro de ecosistemas representativos del mar profundo mediante el uso de sistemas de cableado submarino multiparamétrico, plataformas submarinas no cableadas y plataformas submarinas móviles. Al mismo tiempo, aporté nuevas recomendaciones metodológicas sobre protocolos de recolección y análisis de datos específicamente ajustadas a las diferentes particularidades y necesidades de las susodichas tecnologías de observación submarina. Los resultados de este trabajo han ayudado a comprender mejor la regulación que los ciclos ambientales ejercen sobre el comportamiento rítmico de los animales, revelando que los principales factores ambientales que gobiernan las comunidades bentónicas de aguas profundas siguen siendo el ciclo día-noche de forma indirecta y el mareal de forma más directa que actúan modulando los desplazamientos endobentónicos, bentopelágicos y migraciones nektobentónicas.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

26

Heslop, Emma. „Unravelling high frequency and sub-seasonal variability at key ocean circulation 'choke' points : a case study from glider monitoring in the western Mediterranean sea“. Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/375360/.

Der volle Inhalt der Quelle

Annotation:

A quiet revolution is taking place in ocean observations: in the last decade new multiplatform ocean observatories have been progressively implemented in forward looking countries with ocean borders of economic and strategic importance. These developments are designed to fill significant gaps in our knowledge of ocean state and ocean variability through long-term science and society led monitoring. These new ocean observatories are now delivering results, not only the headline results of single issue experiments, but careful and systematic improvements in our knowledge of ocean variability, and thereby, increasing ocean forecast skill, the ability to link physical process to ecosystem response and to detect the impact of future climatic change. This PhD has used data from a recently initiated glider monitoring program to characterise variability in key components of the Mediterranean circulation that act through the Ibiza Channel. The Ibiza Channel is a key ‘choke’ point in the Mediterranean basin scale circulation and governs an important north/south exchange of different water mass that is known to impact regional ecosystems, in a zone of high biodiversity. The quasi-continuous glider sampling at this critical location has enabled important sub-seasonal to seasonal variability to be captured, and models to be developed to characterise the previously described ‘complex’ pattern of exchange. For the first time, glider monitoring revealed high frequency variability in the transport of water mass, of the same magnitude as the previously characterised seasonal cycle, but occurring over timescales of days to weeks. Although previous ship surveys had noted high cruise-to-cruise variability, they were insufficient to show that in fact water volumes exchanged through the Ibiza Channel vary on ‘weather’ timescales. Using the glider data in combination with an 18-year record of ship missions, long-term seasonal cycles in the north/south exchange were characterised. New month-by-month patterns were defined for the southward transport, while generally held views regarding the seasonality of the northward transport were revised. The pattern of the exchange was further characterised by 4 proposed seasonal ‘modes’, which reflect an annual interplay between vigorous mesoscale and basin scale dynamics. Restricted ‘choke’ points between our ocean basins are critical locations to monitor water transport variability, as they constrain the inter-basin exchange of heat, salt and nutrients. The Ibiza Channel is one such location. In addition to characterising key components of the regional circulation, this PhD also provides insight into use of glider monitoring at such critical locations, which can be used to inform multi-platform ocean observation strategy. This study is part of the quiet revolution.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

27

Kinda, Bazile. „Acoustic remote sensing of Arctic Sea Ice from long term soundscape measurements“. Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00940393.

Der volle Inhalt der Quelle

Annotation:

La fonte rapide des glaces de l'Arctique dans le contexte actuel du réchauffement climatique est un sujet scientifique majeur de ces 30 dernières années. L'Arctique joue un rôle fondamental dans l'équilibre du climat et requiert une attention particulière. Les régions arctiques sont alors surveillées par des observations satellitaires et des mesures in-situ. L'impact climatique de la fonte totale de la glace arctique est encore mal connu. Des recherches sont donc nécessaires pour le suivi à long terme de l'Océan Arctique, en particulier la dynamique spatio-temporelle de la couverture de glace et ses conséquences sur les écosystèmes. La disparition de la banquise en Arctique sera progressivement accompagnée de l'installation d'activités industrielles saisonnières ou pérennes. Ceci a pour conséquences une modification des paysages acoustiques sousmarins de ces environnements jusqu'alors préservés des sources sonores anthropiques. La présente étude, portée sur les paysages acoustiques sous-marins des régions océaniques polaires du Canada, s'inscrit dans ce contexte sous deux axes. Le premier axe de notre étude concerne donc les conséquences directes de la disparition de la glace sur les paysages acoustiques sous-marins de l'Arctique et des mers subarctiques du Canada. Nous avons alors examiné le bruit ambiant, ses variations saisonnières ainsi ses pilotes environnementaux. Un algorithme dédié à l'estimation de cette composante du bruit océanique a été développé à cet effet, afin de constituer des séries temporelles longue durée. A travers des analyses statistiques, nous avons établi que les variables environnementaux responsables de la production du bruit de fond dépendent de l'état de la surface océanique et que pendant la période hivernale, ce bruit est piloté par les mêmes variables environnementales qui gouvernent la circulation océanique à grande échelle de l'Arctique. Le second axe abordé au cours de ce travail de thèse vise à évaluer le potentiel de l'acoustique passive comme moyen de monitorage de la dynamique spatio-temporelle de la banquise. Pour ce faire, nous avons identifié des événements acoustiques signant de phénomènes physiques sous la glace afin d'améliorer la compréhension de leur mécanisme de production. Nous avons ainsi pu lier divers transitoires acoustiques à des processus de déformation de la banquise.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

28

Tichý, Jiří. „Multi-body modely dynamických soustav s elektro-mechanickými rezonátory“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-443721.

Der volle Inhalt der Quelle

Annotation:

This thesis is dealing with creation of computation model of energy harvestors. Harvestors based on translational motion and planar motion were modeled. These models were created in MSC Adams. Proposed harvestors are tranforming mechanical vibrations into electrical energy by electromagnetical induction. To achieve better electrical output, harvestors were tuned to natural frequency suitable for chosen aplication. First proposed harvestor is meant for railway track. For validation of its usability in intended application, model of railway track section is also proposed. Force generated by passing train is used for excitation of the track model. Second harvestor is nonlinear electromechanical oscilator proposed for use on unanchored sea buoy (drifter). After retuning previously proposed concept of energy harvestor to natural frequency 1.6 Hz, computation model for simulation purposes was created. After the simulation of sinusoidal excitation, the excitation based on real sea data was simulated. When excited by regular sea, the peak electric power 9 W was achieved. When excited by irregular sea the peak electrical power of the generator was 7.5 mW.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

29

Lundberg, Kristina. „Monitoring as an instrument for improving environmental performance in public authorities : Experience from Swedish Infrastructure Management“. Doctoral thesis, Stockholm : Department of Land and Water Resources Engineering, Royal Institute of Technology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10117.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

30

Nilsson, Jenny A. U. „On methods for estimating oceanic flow“. Doctoral thesis, Stockholm University, Department of Meteorology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7343.

Der volle Inhalt der Quelle

Annotation:

The aim of this thesis was to estimate and possibly quantify ocean flow by utilizing conventional and novel observational methods as well as model results. Motionally induced voltages, from a cable-based observational system in the Baltic Sea, were analysed to determine their utility for ocean monitoring. The data set was examined as regards the influence of single- and multi-layer flow. Correlation analyses undertaken in the first study showed that the geoelectric installation is capable of providing good estimates of the net flow across the Visby-Västervik transect. The second study focused on possible effects of multi-layer flow on the signal. Comparisons were made with tidal-gauge geostrophic flow estimates, and a good agreement was found, except for a few brief winter periods characterized by significant discrepancies. The velocity fields from a three-dimensional model showed that these events coincided with strong surface and bottom currents, and hence the attenuated voltage signal was suggested as being caused by the non-uniform velocity distribution.

The third study dealt with the deep-water flow through the Understen-Märket trench. Observational data indicated that this flow could be described by applying hydraulic theory. Since the passage is narrow compared to the internal Rossby radius of deformation, rotational effects could be neglected to lowest order. The theoretical predictions proved to agree well with the observational results.

The final study examined the effects of the heat flux and the wind forcing on the circulation in Bahía de Concepción, Chile, where three field surveys were undertaken during the extended austral summer 2002. Hydrographic and current measurements were compared to local tidal-gauge records. Rough estimates of the barotropic and the baroclinic flow across the transect indicated an unusual vortex circulation during periods of weak wind forcing and strong surface heating; results which were corroborated by numerical simulations.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

31

Meyer, Matthias. „The adjoint method of optimal control for the acoustic monitoring of a shallow water environment“. Doctoral thesis, Universite Libre de Bruxelles, 2007. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210610.

Der volle Inhalt der Quelle

Annotation:

Originally developed in the 1970s for the optimal control of systems governed by partial differential equations, the adjoint method has found several successful applications, e.g. in meteorology with large-scale 3D or 4D atmospheric data assimilation schemes, for carbon cycle data assimilation in biogeochemistry and climate research, or in oceanographic modelling with efficient adjoint codes of ocean general circulation models.

Despite the variety of applications in these research fields, adjoint methods have only very recently drawn attention from the ocean acoustics community. In ocean acoustic tomography and geoacoustic inversion, where the inverse problem is to recover unknown acoustic properties of the water column and the seabed from acoustic transmission data, the solution approaches are typically based on travel time inversion or standard matched-field processing in combination with metaheuristics for global optimization.

In order to complement the adjoint schemes already in use in meteorology and oceanography with an ocean acoustic component, this thesis is concerned with the development of the adjoint of a full-field acoustic propagation model for shallow water environments.

In view of the increasing importance of global ocean observing systems such as the European Seas Observatory Network, the Arctic Ocean Observing System and Maritime Rapid Environmental Assessment (MREA) systems for defence and security applications, the adjoint of an ocean acoustic propagation model can become an integral part of a coupled oceanographic and acoustic data assimilation scheme in the future.

Given the acoustic pressure field measured on a vertical hydrophone array and a modelled replica field that is calculated for a specific parametrization of the environment, the developed adjoint model backpropagates the mismatch (residual) between the measured and predicted field from the receiver array towards the source.

The backpropagated error field is then converted into an estimate of the exact gradient of the objective function with respect to any of the relevant physical parameters of the environment including the sound speed structure in the water column and densities, compressional/shear sound speeds, and attenuations of the sediment layers and the sub-bottom halfspace. The resulting environmental gradients can be used in combination with gradient descent methods such as conjugate gradient, or Newton-type optimization methods tolocate the error surface minimum via a series of iterations. This is particularly attractive for monitoring slowly varying environments, where the gradient information can be used to track the environmental parameters continuously over time and space.

In shallow water environments, where an accurate treatment of the acoustic interaction with the bottom is of outmost importance for a correct prediction of the sound field, and field data are often recorded on non-fully populated arrays, there is an inherent need for observation over a broad range of frequencies. For this purpose, the adjoint-based approach is generalized for a joint optimization across multiple frequencies and special attention is devoted to regularization methods that incorporate additional information about the desired solution in order to stabilize the optimization process.

Starting with an analytical formulation of the multiple-frequency adjoint approach for parabolic-type approximations, the adjoint method is progressively tailored in the course of the thesis towards a realistic wide-angle parabolic equation propagation model and the treatment of fully nonlocal impedance boundary conditions. A semi-automatic adjoint generation via modular graph approach enables the direct inversion of both the geoacoustic parameters embedded in the discrete nonlocal boundary condition and the acoustic properties of the water column. Several case studies based on environmental data obtained in Mediterranean shallow waters are used in the thesis to assess the capabilities of adjoint-based acoustic inversion for different experimental configurations, particularly taking into account sparse array geometries and partial depth coverage of the water column. The numerical implementation of the approach is found to be robust, provided that the initial guesses are not too far from the desired solution, and accurate, and converges in a small number of iterations. During the multi-frequency optimization process, the evolution of the control parameters displays a parameter hierarchy which clearly relates to the relative sensitivity of the acoustic pressure field to the physical parameters.

The actual validation of the adjoint-generated environmental gradients for acoustic monitoring of a shallow water environment is based on acoustic and oceanographic data from the Yellow Shark '94 and the MREA '07 sea trials, conducted in the Tyrrhenian Sea, south of the island of Elba.

Starting from an initial guess of the environmental control parameters, either obtained through acoustic inversion with global search or supported by archival in-situ data, the adjoint method provides an efficient means to adjust local changes with a couple of iterations and monitor the environmental properties over a series of inversions.

In this thesis the adjoint-based approach is used, e.g. to fine-tune up to eight bottom geoacoustic parameters of a shallow-water environment and to track the time-varying sound speed profile in the water column.

In the same way the approach can be extended to track the spatial water column and bottom structure using a mobile network of sparse arrays.

Work is currently being focused on the inclusion of the adjoint approach into hybrid optimization schemes or ensemble predictions, as an essential building block in a combined ocean acoustic data assimilation framework and the subsequent validation of the acoustic monitoring capabilities with long-term experimental data in shallow water environments.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

APA, Harvard, Vancouver, ISO und andere Zitierweisen

32

Parent, Briz. „Développement d’un indice biotique basé sur les foraminifères benthiques ; : application sur la façade méditerranéenne française“. Thesis, Angers, 2019. http://www.theses.fr/2019ANGE0012/document.

Der volle Inhalt der Quelle

Annotation:

Les milieux côtiers subissent de fortes pressions dues aux activités anthropiques. Ces pressions vont parfois impacter les écosystèmes benthiques. En Europe, des réglementations internationales, telle que la Directive Cadre sur l’Eau (DCE), ont vu le jour. La DCE a fixé un cadre pour obtenir le retour et le maintien d’un bon état écologique pour les masses d’eau côtières, jusqu’à un mile de la côte. Pour vérifier si ce bon état écologique est atteint, des outils de mesure adaptés et performants sont nécessaires. L’utilisation d’indices biotiques basés sur les faunes de foraminifères benthiques est un des moyens pour mesurer l’état des écosystèmes. Ces indices basés sur les faunes de foraminifères sont en pleine expansion, notamment en Méditerranée. En termes de méthodologie, nous avons pu améliorer une technique de concentration des foraminifères benthiques par séparation par densité, qui accélère le traitement des échantillons. L’indice TSI-Med a la particularité d’apporter une correction pour l’état trophique naturel, c’est-à-dire le taux d’enrichissement naturel en matière organique, sur la base de la granulométrie du sédiment. Nos données suggèrent néanmoins que cette correction est encore insuffisante. Nous avons également comparé plusieurs indices biotiques basés sur les faunes de foraminifères benthiques le long des côtes méditerranéennes françaises. Les indices basés sur la diversité, notamment l’exp(H’bc), ne sont pas adaptés à notre zone d’étude oligotrophe. Les indices basés sur les groupes écologiques d’espèces que nous avons testés (TSI-Med, Foram-AMBI et FSI) sont plutôt bien corrélés. Le principal facteur qui va induire des différences entre ces indices est la liste d’assignation écologique des espèces. Trop d’espèces n’ont pas encore été assignées et l’assignation de plusieurs espèces majeures est problématique. Néanmoins, nous avons montré que ces indices sont efficaces à détecter l’impact d’un enrichissement en matière organique diffus et/ou provenant de source ponctuelle, telle que les rejets de stations d’épuration (côte israélienne). Pour perfectionner ces indices, des efforts de caractérisation écologique des espèces doivent être poursuivis
Coastal environments suffer from anthropogenic activities. Various types of pressure can have large impacts on benthic ecosystems. In Europe, international regulations, such as the Water Framework Directive (WFD), have been implemented. The WFD aims to attain and sustain a good ecological status for all coastal waters, up to one mile from the coast. To verify whether this good status has been reached, adapted and efficient measuring tools are needed. The use of biotic indices based on foraminiferal faunas are a mean to assess the ecosystem status. The use of indices based on foraminiferal faunas rapidly increases, especially in the Mediterranean. In terms of methodology, we were able to improve a method to concentrate benthic foraminifera by density separation, which accelerates the sample treatment. The TSI-Med index includes a correction to take into account the natural trophic state, i.e., the natural enrichment rate in organic matter, on the basis of sediment grain size. However, our data suggest that the applied correction is still insufficient. We also compared several biotic indices based on benthic foraminiferal faunas along the French Mediterranean coast. Indices based on diversity, such as the exp(H’bc), are not suited for our oligotrophic study area. The results of three tested indices based on ecological groups (TSI-Med, Foram-AMBI, FSI) are well correlated. The main factor inducing differences between the indices is the list of ecological assignments for the various species. In general, too many species have not yet been assigned to ecological categories and the assignment of several major species is problematic. Nevertheless, we show that the indices are already efficient in detecting the impact of diffusive organic matter enrichment or enrichment from point sources, such as sewage outlets (Israelian coast). To further perfection the foraminiferal indices, the efforts of ecological assignments of species have to be continued

APA, Harvard, Vancouver, ISO und andere Zitierweisen

33

Rabassa, Camila Mendonça. „Monitoramento geotécnico da obra de ampliação dos molhes do Rio Grande, Brasil“. reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2010. http://hdl.handle.net/10183/49292.

Der volle Inhalt der Quelle

Annotation:

O presente trabalho apresenta um estudo das condições geotécnicas e do monitoramento da obra de ampliação dos molhes, proteção da entrada do canal de navegação do Porto de Rio Grande-RS/ Brasil, assente em solos moles. Atenção é dada a problemas associados à capacidade de carga e recalque das fundações. Investigações indicaram que o solo de fundação é constituído de uma camada de areia com 3 a 5 m de espessura abaixo do piso marinho, seguida de camada de argila mole, com índice NSPT de 2 a 4 e espessura média de 15 m. Somente abaixo dessa profundidade ocorrem solos de maior resistência. Deste modo, antecipou-se no projeto que as camadas do subsolo marinho iriam sofrer recalques e deslocamentos significativos quando submetidas às cargas decorrentes do alteamento dos molhes, havendo a necessidade de garantir as condições de estabilidade a partir da construção de bermas de equilibrio. Devido aos riscos, a obra foi concebida como observacional, sendo acompanhada de instrumentação de controle do processo construtivo, incluindo a observação das poro-pressões, recalques e deslocamentos horizontais na camada de argila mole, compressível e de baixa resistência. A instrumentação implantada na obra inclui inclinômetros, medidores do tipo aranha e piezômetros, sendo tal instrumentação pioneira no Brasil em obras nearshore, pois devido às condições marítimas adversas, parte dos instrumentos envia os dados via rádio, com monitoramento contínuo em tempo real. Este trabalho apresenta relatos das etapas da obra, incluindo a investigação das condições do subsolo e a instalação da instrumentação, constituindo-se igualmente em um desafio devido à profundidade, às restrições de acesso, ventos, impacto de ondas e correntes. Os resultados da instrumentação foram analisados e sistemas de alerta foram implantados para garantir as condições de segurança durante todas as etapas construtivas dos molhes.
The present work presents the study of the geotechnical conditions and the monitoring of the breakwaters enlargement work in Rio Grande-RS/Brazil. The breakwaters are the protection for the Rio Grande harbor channel, based on soft soils. Focus is given to problems associated to the load and settlements of the foundations. Investigations have indicated that the soil is constituted of a 3 to 5 meter thick sand layer under the sea floor, followed by a soft clay layer with NSPT between 2 and 4 and 15 meter average thick. Only under this depth soils with larger strength occur. Therefore, it was predicted in the project that the layers from the sea subsoil would experience considerable settlements and displacements when they undergo the loads from the breakwaters heightening, existing the need to ensure stability conditions with the construction of balance berms. Due to risks, the work was conceived as observational and it has been accompanied by a control instrumentation of the constructive process, including pore water pressure observations as well as horizontal and vertical displacements in the clay layer. The implemented instrumentation includes inclinometers, spider magnet meters and piezometers. The use of these instrumentations has been considered pioneer in nearshore works in Brazil because, due to the adverse sea conditions, part of them send data by radio signal, with continuous monitoring on real time. This work presents reports from the steps taken in the work, including the investigation of the subsoil conditions and the installation of the instrumentation, which had constituted a challenge due to the depth, access restriction, wind, wave impact and the sea flow. Instrumentation results were analyzed and alert systems were deployed to ensure safety conditions during all the constructive steps of the breakwaters.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

34

Popattanachai, Naporn. „Regional cooperation addressing marine pollution from land-based activities : an interpretation of Article 207 of the Law of the Sea Convention focusing on monitoring, assessment, and surveillance of the pollution“. Thesis, Nottingham Trent University, 2018. http://irep.ntu.ac.uk/id/eprint/33374/.

Der volle Inhalt der Quelle

Annotation:

Marine Pollution from Land-based Activities (MPLA) has long been recognised as being the biggest contributor to the deterioration of the marine environment. Despite the recognition, this source of pollution remains largely unregulated. The United Nations Convention on the Law of the Sea (LOSC) is the only international agreement that regulates MPLA at the global level. However, Article 207 of the LOSC requiring States to prevent, reduce, and control MPLA has been criticised for its lack of clarity and cannot guide States’ action to fulfil their obligation. This research picks up from this ambiguity and tries to clarify the substance of Article 207 of the LOSC. It specifically focuses on the regional aspect of this provision. The question of this research is 'how and to what extent should States act at the regional level to fulfil their obligation under Article 207 of the LOSC.' In so doing, it answers the question through the lens of treaty interpretation showing what the possible interpretations are and how States have interpreted Article 207 of the LOSC from their subsequent practice both at global and regional levels. To fulfil this obligation at the regional level, States have interpreted Article 207 of the LOSC as a single combined obligation treating the obligations to prevent, reduce, and control MPLA collectively. Besides, when applying at the regional level, the obligation to prevent, reduce, and control MPLA comprises four key components. In particular, at the regional level, monitoring, assessment, and surveillance of MPLA have been developed to varying degrees to be part of the regional aspect of this obligation. Monitoring and assessment of MPLA are essential and can be part of the obligation, whereas surveillance of MPLA remains to be further developed.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

35

Chatzievangelou, Damianos [Verfasser], Laurenz [Akademischer Betreuer] Thomsen, Laurenz [Gutachter] Thomsen, Joachim [Gutachter] Vogt, Jacopo [Gutachter] Aguzzi und Jakob [Gutachter] Schwendner. „On Monitoring, Evaluating and Managing Benthic Ecosystems with Internet Operated Deep-sea Crawlers; The Case of Barkley Canyon Hydrates / Damianos Chatzievangelou ; Gutachter: Laurenz Thomsen, Joachim Vogt, Jacopo Aguzzi, Jakob Schwendner ; Betreuer: Laurenz Thomsen“. Bremen : IRC-Library, Information Resource Center der Jacobs University Bremen, 2020. http://d-nb.info/1203876017/34.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

36

Soto, Inia M. „Environmental variability in the Florida Keys : impacts on coral reef health“. [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001780.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

37

Stokes, Kimberley Laura. „Ecology of marine turtles under climate change“. Thesis, University of Exeter, 2014. http://hdl.handle.net/10871/21847.

Der volle Inhalt der Quelle

Annotation:

Climate change threatens to disrupt biological systems around the globe, sparking debate over natural capacity for adaptation in a fragmented landscape. Marine turtles are evolutionarily ancient and have survived millions of years of prehistoric climate change, but are threatened by the rapidity of modern warming and a history of severe overexploitation that has left most populations depleted. This thesis explores a nesting aggregation of the green turtle (Chelonia mydas) in northern Cyprus, where a longitudinal programme of both intensive and extensive monitoring enables insight into individual and population level parameters and processes. Nesting on the two coastlines covered by this project is in the early stages of recovery, possibly in response to exhaustive nest protection efforts over the last twenty years. Saturation tagging at one key site allows us to confirm that recruitment of new breeders is an important driver of this trend, and that average clutch frequency has remained stable around three nests per female per year, validating nest-count derived abundance estimates at a regional scale. Concern has been raised, however, regarding recent changes in fishing practices which are impacting the local juvenile neritic phase, which may have a lagged effect on the recovery of this nesting population. A collaborative tracking effort including all other countries with major nesting in the Mediterranean allows us to identify major foraging grounds for this species, with two hotspots accounting for >50% of tracked individuals, as well as coastal and pelagic seasonal corridors of high use. Bycatch levels and mortality rates for turtles in these key areas are largely unknown and should be prioritised for investigation. Hatchling sex ratios from the main study beach are extremely female-biased (estimated 97% female for the twenty year period 1993-2012). A 1oC rise in average incubation temperatures threatens near complete hatchling feminisation on this beach, whilst a 2oC rise could reduce hatch success to less than 50%. Thermal effects on hatchling morphometrics are evident, with a 1oC rise in temperature reducing average length, width and weight by 1%, 2% and 3% respectively. More favourable incubation conditions were found early in the season, in deeper nests laid by larger females, and on beaches of lighter sand. In contrast, adult sex ratios at the main site are male-biased, posing questions regarding sex-specific survival rates and optimal hatchling sex ratios. A phenological shift towards earlier nesting is demonstrated for the first time in this species, and could potentially ameliorate warming effects. Carry-over climate forcing effects from the foraging ground influence the breeding frequency of individuals, driving population level responses in annual magnitude of nesting. This work emphasises the utility and necessity of long-term individual-based monitoring programmes in elucidating population trends and climate responses in iteroparous species with non-annual breeding.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

38

Hannerz, Fredrik. „Making water information relevant on local to global scale : the role of information systems for integrated water management /“. Doctoral thesis, Stockholm : Department of Physical Geography and Quaternary Geology, Stockholm university, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7431.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

39

Gianni, Fabrizio. „Conservation et restauration écologique des forêts marines Méditerranéennes“. Thesis, Nice, 2016. http://www.theses.fr/2016NICE4028/document.

Der volle Inhalt der Quelle

Annotation:

Une perte des forêts marines de grandes algues brunes a été observée dans les récentes décennies, causant un changement des écosystèmes et une réduction de la biodiversité. Dans le cadre du projet MMMPA, ce travail de thèse vise à répondre à certaines importantes questions liées à la conservation et à la restauration des forêts d'algues, au rôle des Aires Marines Protégées (AMPs) et les poissons herbivores. Les résultats des expériences sur le terrain ont montré que les poissons herbivores indigènes, probablement Salpa Sarpa (saupes), peuvent être les herbivores les plus efficace des ceintures intertidales de Cystoseira. En effet, les saupes affectent fortement la croissance, la biomasse et la reproduction des forêts naturelles et limitent le succès de la restauration sur des substrats artificiels. Le rôle des poissons herbivores a probablement été négligé dans la régulation des communautés macroalgales Méditerranéennes. Une revue de la littérature existante a montré une amélioration de l'intérêt scientifique (articles publiés) sur les espèces formant les forêts marines, au cours des dernières décennies. Cependant, la plupart de la recherche scientifique n’est pas en relation avec les AMPs, probablement parce que les forêts marines ne sont pas toujours considérées pendant la création des AMPs et dans les plans de gestion. Les études sur les forêts marines étant concentrée dans les pays développés, elles ne sont pas réparties de manière homogène dans le monde
Loss of marine forests of large brown seaweeds has been observed in recent decades, causing a reduction of ecosystem biodiversity. In the framework of the MMMPA project, this PhD aimed to address some important topics related to the conservation and restoration of algal forests, the role of Marine Protected Areas (MPAs) and fish herbivory. Different approaches were used: macroalgae surveys, literature reviews, manipulative experiments, tank-based experiments and GIS habitat mapping. Results from field experiments showed that native herbivorous fish, likely Sarpa salpa (salemas), can be the most effective herbivore of intertidal Cystoseira belts both on natural and artificial substrates. Indeed, salemas strongly affected the growth, biomass and reproductive output of natural forests and limited restoration success on artificial substrates. Likely, the role of the herbivorous fish in structuring macroalgal communities has been overlooked in the Mediterranean Sea so far. A review of the existing literature showed that knowledge on marine forests forming species has improved in recent decades. However, most of the research is not in relation to MPAs, likely due to the fact that marine forests are not always included in MPAs planning and management plans. Studies on marine forests are not homogeneously distributed in the world, being concentrated in the developed countries. Interestingly, an increase of the scientific interest (published papers) was observed. Nowadays, marine forests are under continuous threats and especially sensitive to multiple impacts

APA, Harvard, Vancouver, ISO und andere Zitierweisen

40

Bouffaut, Léa. „Detection and classification in passive acoustic contexts : application to blue whale low-frequency signals Passive stochastic matched filter for Antarctic blue whale call detection, in The Journal of the Acoustical Society of America 144 (2), 2018 Baleen whale distribution and seasonal occurrence revealed by an ocean bottom seismometer network in the Western Indian Ocean, in Deep Sea Research Part II: Topical Studies in Oceanography 161, March 2019“. Thesis, Brest, 2019. http://www.theses.fr/2019BRES0057.

Der volle Inhalt der Quelle

Annotation:

L’analyse des grands volumes de données générés par la surveillance par acoustique passive long-terme et continue des baleines bleues (BW) est améliorée par la détection automatisée des signaux d’intérêt. Le travail présenté dans cette thèse s’attaque au problème de la détection et classification de signaux stéréotypés dans un contexte passif basse fréquence où les signaux sont modifiés par le canal de propagation, bruités et où le SNR varie continuellement. Les méthodes développées sont appliquées à des enregistrements issus d’OBS déployés dans l'océan Indien occidental.Premièrement, le filtrage adapté stochastique (SMF) est étendu au contexte passif en adaptant l’estimation du bruit et du SNR. Ce filtre est appliqué avec succès pour la détection des calls de baleine bleue antarctique et est comparé aux MF et Z-detector sur données annotées présentant de nombreux bruits et d’importantes variations du SNR. Les excellentes performances du SMF passif permettent d’augmenter la portée de détection jusqu'à 100 km en présence de bruit de bateau.La détection simultanée de différentes espèces s’appuie sur un schéma de reconnaissance de formes où les signaux tonaux de BW sont extraits, caractérisés et classifiés pour la transcription automatique des chants.Les signaux ainsi identifiés sont ensuite reconstruits avec des formes d'onde distinctes reproduisant les chants sous-jacents. Le succès de la reconstruction repose sur la qualité de la détection de tonales: le détecteur de crêtes est choisi pour son efficacité. Les résultats d'apprentissage et la première application non supervisée de la transcription ont révélé des résultats prometteurs et son utilité pour l’analyse multi-espèces
The analysis of the large volumes of data resulting from continuous and long-term monitoring efforts of blue whales (BWs) benefits from the automated detection of target signals. This thesis investigates the challenging problem of the detection and classification of stereotyped signals in a low-frequency passive acoustic context where (1) signals traveling long distances are deteriorated by the propagation channel, (2) overlapping noises interfere and, (3) SNRs vary continuously. Developed methods are applied to recordings from ocean bottom seismometers deployed in the western Indian Ocean.First, the stochastic matched filter (SMF) is adapted to the passive context by overcoming noise estimation and estimating the SNR automatically. This filter is successfully applied to the detection of Antarctic blue whales calls and is compared to the MF and the Z-detector on an annotated ground-truth dataset exhibiting various SNRs and noises. The passive SMF showed better performances, increasing the detection range up to 100 km in the presence of ship noise.The problematic of the detection of concurrently calling species is addressed based on a pattern recognition development for the automatic transcription of BW songs where, tonal signals are extracted, characterized, and classified. The hence identified signals are then reconstructed as separate waveforms reconstructing of the underlying songs. The success of the reconstruction relies on the quality of the tonal detector: the ridge detector was chosen for its efficiency. Training and unsupervised application revealed promising results of the proposed transcription method and its utility for multi-species analysis

APA, Harvard, Vancouver, ISO und andere Zitierweisen

41

Boyé, Aurélien. „Diversité taxinomique et fonctionnelle des habitats benthiques dans l'espace et dans le temps : une perspective régionale et décennale Constancy despite variability: Local and regional macrofaunal diversity in intertidal seagrass beds ?, in Journal of Sea Research 130, December 2017“. Thesis, Brest, 2018. http://www.theses.fr/2018BRES0110.

Der volle Inhalt der Quelle

Annotation:

Ce travail de thèse s’appuie sur les données d’un suivi à long-terme mené à une échelle régionale pour mieux appréhender les facteurs gouvernant la diversité des fonds marins côtiers. En considérant de multiples échelles spatiales et temporelles ainsi que différentes facettes de la diversité de ces communautés, l’objectif principal a été de fournir des connaissances permettant de mieux prédire les potentielles réponses des communautés benthiques face aux changements environnementaux à venir. Cette thèse s’inscrit en particulier dans un contexte de la menace de l’homogénéisation des fonds marins et de la disparition à large échelle des habitats biogéniques, réservoirs de biodiversité formés par des espèces fondatrices. La comparaison de deux de ces habitats, les herbiers de Zostères intertidaux et les bancs de mäerl subtidaux, à des sédiments dépourvus d’espèces fondatrices a mis en évidence le rôle fondamental de ces habitats biogéniques dans le maintien de la diversité et du fonctionnement des fonds marins à long-terme. Ils contrôlent profondément les dynamiques temporelles des communautés et leurs capacités de réponse aux variations des conditions environnementales, assurent une plus grande stabilité des structures spatiales des communautés à une échelle régionale. Ils semblent par-là essentiels au maintien à long-terme des fonctions écologiques auxquelles contribuent les espèces benthiques. Cependant, ce travail montre que ces espèces fondatrices opèrent selon des mécanismes différents et que les implications en terme de vulnérabilité des communautés sont donc aussi différentes. Cette étude montre enfin qu’au sein d’un habitat donné, la richesse locale des communautés est relativement stable dans l’espace et le temps et met en évidence le besoin de caractériser les variations de compositions de communautés pour guider les actions de conservations à larges échelles. À ce titre, et à l’échelle régionale, les variations de composition contribuent à une richesse taxinomique et fonctionnelle dans les sédiments dépourvus d’espèces fondatrices aussi importante que dans les habitats biogéniques.Ce résultat impose de réévaluer la valeur de conservation qui pourrait leur être attribué de part leur richesse locale limitée. Les suivis à grandes échelles spatiales et temporelles sont dans ce contexte essentiels pour fournir un lien entre les connaissances empiriques et théoriques existantes à des échelles locales, et les échelles supérieures auxquelles s’intéressent les politiques de conservation
This thesis takes advantage of long-term monitoring data covering a regional scale to better apprehend the maindrivers of the diversity of coastal seafloors. Through consideration of multiple spatial and temporal scales and different facets o fcommunity diversity, the main objective of this work was to provide a better predictive understanding of the responses of benthic communities to environmental changes. In particular, this thesis addressed the potential consequences of the on-going homogenisation of the seafloor and the global loss of biogenic habitats, havens of diversity made by foundation species. Through comparison of two such habitats, intertidal seagrass meadows and subtidal maerl beds, with bare sediment devoid of foundationspecies, this thesis has highlighted the key role of biogenicstructures for long-term maintenance of the diversity andfunctioning of benthic communities. Indeed, these habitats mediate the dynamics and responses of benthic communities to environmental conditions, ensure a greater stability of their spatial structures at regional scale, and appeared essential for the long-term maintenance of the ecological functions benthic invertebrates are associated with. This work also highlighted that foundation species may affect benthic communities through different mechanisms, and that has implications on the structure and vulnerability of these communities. Lastly, this the sisemphasized a strong spatial and temporal stability of community richness despite important underlying changes in composition and there by stressed the need to better characterise these compositional variations to guide conservation. These variations contributed, for instance, to an unexpectedly high taxonomic and functional richness of bare sediment at regional scale,similar to those of biogenic habitats, despite being locally depauperate. Overall, broad-scale monitoring programs are fundamental assets to bridge local empirical and theoretical ecological knowledge to the broader scales at which society manage and benefits from natural ecosystems

APA, Harvard, Vancouver, ISO und andere Zitierweisen

42

Shinn, Richard J. „The United Nations monitoring system - applications for North Korea“. Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1995. http://edocs.nps.edu/npspubs/scholarly/theses/1995/Sep/95Sep_Shinn.pdf.

Der volle Inhalt der Quelle

Annotation:

Thesis (M.S. in Systems Technology (Scientific and Technical Intelligence)) Naval Postgraduate School, Sept. 1995.
Thesis advisor(,):Peter Lavoy, Vicente Garcia. "September 1995" Includes bibliographical references (p. 81-82). Also available online.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

43

Bily, Mollie A. „Study of composite interface strength and crack growth monitoring using carbon nanotubes“. Thesis, Monterey, California : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Sep/09Sep%5FBily.pdf.

Der volle Inhalt der Quelle

Annotation:

Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, September 2009.
Thesis Advisor(s): Kwon, Young W. "September 2009." Description based on title screen as viewed on November 04, 2009. Author(s) subject terms: Carbon Nanotubes, CNTs, Carbon Fiber Composite, Fiberglass Composite, Crack Propagation, Mode II, Health Monitoring, Resistance Testing Includes bibliographical references (p. 77-78). Also available in print.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

44

Lourenço, Daniela de Freitas. „Wireless sensor network for Salicornia plantation monitoring“. Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/23847.

Der volle Inhalt der Quelle

Annotation:

mestrado em Engenharia Eletrónica e Telecomunicações
A Salicornia ramosissima é uma planta que cresce em ambientes salinos sendo famosa pelas suas características benéficas nas mais diversas áreas, tais como alimentação, medicina e biocombustíveis. Na Universidade de Aveiro, um grupo de investigadores na área da biologia contribuíram para uma melhor compreensão do crescimento e desenvolvimento da Salicornia na Ria de Aveiro no que diz respeito à salinidade, fases de crescimento e sobrevivência. No contexto da Internet das Coisas, as redes de sensores são um tema de estudo dado o vasto número de aplicações, pelo que, diversas tecnologias têm aparecido no mercado de modo a garantir qualidade de serviço aos seus clientes. Foi assim proposto o desenvolvimento de uma solução que monitorize os parâmetros desta planta no seu habitat natural. Uma vez que este ambiente é selvagem e propício a roubos, os requisitos principais são: consumos energéticos e custos de desenvolvimento e implementação baixos. Ao longo desta dissertação são apresentadas as tecnologias de redes de sensores actuais no mercado, bem como um estudo sobre os sensores necessários para a monitorização de uma plantação de Salicornia e o protocolo que favorece as necessidades da rede em questão.
The Salicornia ramosissima is a plant that grows in a salt-marsh environment and it has become famous because of their bene cial characteristics in several areas such as: human nutrition, biofuels and medicine. At University of Aveiro, a group of biology researches contributed to a better understanding of a Salicornia population biology in Ria de Aveiro, especially aspects related to salinity, plant growth, and survival. In the context of the Internet of Things, the wireless sensor networks is an emergent area of studies. Nowadays, there are several tecnologies in the market to answer the requirements and o er quality of service to the WSN's users. It was proprosed a solution to monitor the Salicornia parameters in their natural habitat. Once the habitat is considerer wild, it is conducive to theft. Because of that, the main requirements for this network are to create a low cost and low power consumption network. Along this dissertation, are presented and discussed some emergent wireless tecnologies in the market, as well a discussion about the sensors needed to monitor the Salicornia plantation and the communication protocol which answers the needs of the network.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

45

Zou, Min. „Real-time monitoring and control of a noncontacting mechanical face seal“. Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/17650.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

46

Peterson, Therése. „Samspelet mellan ekologi, produktionsförhållande, politik och sociokulturella faktorer gällande Östersjöns torskbestånd från 1970-talet till 2003“. Thesis, Linköping University, Department of Water and Environmental Studies, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2401.

Der volle Inhalt der Quelle

Annotation:

The study begins with a historical background over the fisheries development in North America and in the Baltic Sea area in Finland and Sweden. As we can see the fisheries development depends on the interaction between ecology, state of production, politic and also social factors. In Sweden the fishery politic has changed over the period of the study. In the 1970: s the main politic focus was on the fisheries progress, expansion and rationalization. The State in Sweden took a vast part in this development and gave economic support. In the 1980: s the fishery politic in Sweden started to change and the environmental politics began to enter the fishery politic. The environmental problems in the Baltic Sea were given attention and it was a great anxiety over the eutrophication. In the 1980: s the codpopulation declined and with them the catches declined. The conflict over the White zone 1978-1988 between Former Soviet Union and Sweden resulted in a plunder fishery in the area east of Bornholm. This plunder fishery effected the cod population enormous and the effect has continued to the late 1990: s.

In 1995 Sweden joined the European Union and the common fishery politic replaced the Swedish fishery politic.

The system with TAC (Total Allowable Catch) is central in the common politic and it is used to control the cod catches. But the problem is that the TAC -volume has been higher than the codpopulation could stand. Despite the politic goal in Sweden and EU to preserve the codpopulation in the Baltic Sea, the codpopulation has continued to decline. The reason to this politic failure is that the limit of the ecology has been overseen. Instead, the economic and social values have been dominating the politic and together with a to weak control of the catches and environmental problems in the Baltic Sea, the situation for the cod has been devastating.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

47

Ferguson, Chad Allen. „Environmental Change and Molluscan Death Assemblages: An Assessment of Ecological History Along a Carbonate Bank in Florida Bay“. Cincinnati, Ohio : University of Cincinnati, 2009. http://rave.ohiolink.edu/etdc/view.cgi?acc_num=ucin1250697788.

Der volle Inhalt der Quelle

Annotation:

Thesis (Ph.D.)--University of Cincinnati, 2009.
Advisor: Arnold I. Miller. Title from electronic thesis title page (viewed Nov.24, 2009). Keywords: molluscan death assemblages; subfossil; carbonate bank; body size; sea shell; mollusk; coastal monitoring; seagrass bed; environmental change; anthropogenic; nutrient enrichment; coastal environment; Thalassia; Halodule; Cerithium; Florida Bay; Everglades. Includes abstract. Includes bibliographical references.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

48

Kirkman, Stephen Patrick. „The Cape fur seal : monitoring and management in the Benguela Current ecosystem“. Doctoral thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/11572.

Der volle Inhalt der Quelle

Annotation:

Includes abstract.
Includes bibliographical references.
At the root of this thesis was the Benguela Current Large Marine Ecosystem (BCLME) Programme’s project "Top Predators as Biological Indicators of Ecosystem Change in the BCLME" (LMR/EAF/03/02). The objectives of this project were to assess the utility of top predators as biological indicators of ecosystem change in the Benguela Current Ecosystem, and implement an appropriate, integrated, system-wide monitoring programme based on top predators, to support ecosystem-based management in the Benguela Current Ecosystem.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

49

Söderström, Maria. „Local and global contaminants in Swedish waters : studies on PCBs, DDTs, 4,5,6-trichloroguaiacol and their transformation products in fish and sediments“. Doctoral thesis, Stockholms universitet, Institutionen för miljökemi, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-104291.

Der volle Inhalt der Quelle

Annotation:

This thesis is focused on studies on the environmental fate and methodological improvements for determination of the global contaminants, PCBs and DDTs, and locally discharged phenolics, e.g. 4,5,6-trichloroguaiacol (4,5,6-TCG), and their transformation products. 4,5,6-TCG is released from bleached pulp mills, and was chosen as a model substance, to study its fate and effects in aquatic environments. In a brackish water model ecosystem, 4,5,6-TCG was shown to be transformed via demethylation, dechlorination, and methylation reactions. Marine periphyton exposed to 4,5,6-TCG was shown to form demethylated, brominated and dimeric metabolites. Several of these metabolites were identified and quantified. Also more tightly bound chlorophenolics were recovered from the substrate, after harsh extraction procedures had been applied. Conjugates of chlorophenols in fish bile were determined as useful tracers for monitoring effluents from bleached pulp mills, even in areas far from the discharge point. To facilitate calculations of water concentrations, bile to water bioconcentration factors (bBCF-values) were determined for several phenolics, including also alkali-labile chlorocatechols. PCBs and DDTs, were assessed in Swedish lakes with background exposure of these global contaminants. A methodological study focus on the contamination risks of airborne PCBs, during freeze-drying and storage of dry sediment samples. Eutrophication has been proposed to cause lower levels of pollutants in biota in lakes due to biomass dilution but in this thesis examples of higher levels of PCBs in sediment traps, sediment and in perch, and also in higher fluxes of PCBs to the sediment, were observed. Phytoplankton are supposed to be responsible for most of the transport of the contaminants. The composition of DDTs in soil, sediment traps and in dated sediment cores was studied in some detail. PCBs, DDTs, HCB and HCHs were measured in sediments from 100 reference lakes included in the National Swedish Environmental Program. The lakes have a large variation in lake characteristics, representative for different areas in Sweden. A gradient was observed for sPCB with decreasing levels from the south west towards the north. The results suggests that longrange transport is the dominating mechanism for distribution of the contaminants analysed. In this study the levles of PCBs and DDTs were lower in eutrophic lakes than in oligotrophic lakes, in an area with similar atmospheric exposure.

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Submitted. Paper 6: Manuscript.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

50

Gomes, César Emanuel Brandão. „Fine grained monitoring of electric energy consumption“. Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/10937.

Der volle Inhalt der Quelle

Annotation:

Mestrado em Engenharia Electrónica e Telecomunicações
Hoje em dia assistimos a uma grande pressão e esforço no sentido de estimular a conservação de energia, seja devido a limitações económicas, preocupações ambientais, ou normas regulatórias. No topo do consumo de energia está a energia sob a forma de electricidade Para se conseguir incentivar a utilização eficiente da energia é necessário fornecer consciencialização energética. Se os consumidores de elecricidade tiverem acesso a informação detalhada sobre como, quando e que aparelhos estão a consumir energia, estes poderão tomar boas e bem suportadas decisões e anuir mudar os seus hábitos de modo a reduzir o consumo de energia, e por fim, gastar menos dinheiro. O projecto aqui apresentado desenvolve as bases para um aparelho que fornece informação detalhada sobre o consumo de energia eléctrica para uma casa. A informação a ser fornecida deverá ser separada individualmente para virtualmente cada aparelho singular presente. A técnica escolhida para desenvolver o aparelho foi Monitorização Não Intrusiva de Cargas de Aparelhos. A partir de um único ponto de medida o sistema deverá identificar as cargas individuais na casa, o que faz com que o hardware tenda a ser simples e minimal, recaindo a complexidade para o software. O sistema desenvolvido deverá ser de baixo custo e de fácil instalação. O sistema que foi desenvolvido foi capaz de identificar individualmente e com grande sucesso os aparelhos presentes num ambiente controlado. Ao contrário de outros sistemas deste tipo, o sistema apresentado nesta dissertação é capaz de distinguir cargas eletricamente idênticas, através do uso da técnica de Medição Indirecta de Potência implementada através de uma Rede de Sensores Sem Fios.
Nowadays we witness a great pressure and effort in order to stimulate energy conservation, either due to economic constraints, environmental concerns, or regulatory pressures. At the top of the energy consumption is the consumption of energy in the form of electricity. The first step to improve energy utilization efficiency is energy awareness. So if there is some manner to provide the average person information about how he is consuming electricity, he may take it by its own interest, and In fact, if electricity consumers have access to detailed information about how, when and by which devices energy is consumed, they can make good and well supported decisions on how they can change their habits to spend less energy and ultimately spend less money. The project hereby presented, develops the basis for a device that provides detailed information on electrical energy expenditure for a home. The information to be provided aims to be disambiguated for virtually every individual appliance present. The chosen technique to develop such a device was Non-Intrusive Appliance Load Monitoring. The system identifies individual loads from a single measurement point. That makes that the hardware tends to be simple and minimal, passing the complexity to the software. The system aims to be very low cost and easy to deploy. The system developed was able to identify with great success individual appliances in the total load on a controlled environment. Unlike other systems of this type, the system presented in this dissertation has the ability of disambiguating electrically identical loads, by the use of the technique of Indirect Power Sensing deployed with a Wireless Sensor Network

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Dissertationen zum Thema „Sea monitoring“

Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an