Dissertations / Theses on the topic 'Southwestern'
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Garcia, Juan R., and Ignacio Garcia. "Readings in Southwestern Folklore." Mexican American Studies & Research Center, The University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/624796.
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Reichenbacher, Frank W. "Conservation of Southwestern Agaves." University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/554213.
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The status of Southwestern agaves being considered for listing under the 1973 Endangered Species Act are summarized. Numerous Mexican agaves appear to merit consideration for listing as threatened or endangered species. An outline of action to accomplish this and achieve some much-needed communication between the United States and Mexico is presented. The agaves are clearly of Mexican origin. Species abundance contour maps are used to locate areas and species of special significance in the study of the evolution of the genus and to map out a conservation plan for the genus.
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Hunter, Scott James. "Landslide evolution in southwestern Saskatchewan." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ54713.pdf.
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Walworth, James. "Using Gypsum in Southwestern Soils." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2006. http://hdl.handle.net/10150/144801.
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Klemens, Michael W. "The herpetofauna of southwestern New England." Thesis, University of Kent, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277366.
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The distributions, variations, and abundances of the 45 species of amphibians and reptiles found in southwestern New England (USA) are described and analyzed using multivariate statistical techniques. These data are compared to historical information contained in museums and literature reports. Activity and reproductive parameters are described and compared to published data from other areas of North America. The conservation status of each species is discussed, and where appropriate, recovery strategies proposed.
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Rutaro, Hamid. "Milk quality analysis in Southwestern Uganda." Thesis, Kansas State University, 2015. http://hdl.handle.net/2097/19011.
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Master of AgribusinessDepartment of Agricultural Economics
Vincent Amanor-Boadu
As the dairy industry faces the future, consumers’ demand for better milk quality and safety is increasing. Milk quality is of major interest to both consumers and dairy farmers alike. However, scientific data on milk quality in terms of somatic cell count (SCC) in Uganda and most developing countries has been lacking. This study used SCC to compare Southwestern Uganda’s milk quality against international standards. The study also sought to assess dairy farmers’ perceptions about milk quality. Milk samples were obtained from 100 farms in Mbarara and Kiruhura districts, the major cattle corridor in Uganda. The milk’s SCC was analyzed using a DeLaval DCC. A structured questionnaire surveyed farmers on milking procedures and milk-quality perception. Descriptive statistics and qualitative analysis was used to characterize and compare milk quality against the international benchmark. The study found that the 100 farms had an average SCC of 507,000 cells/ml. About 34% of farms in the study had SCC under 200,000 cells/ml, an indication of high-quality milk. Excluding 7% of the farms with SCC over 1,000,000 cells/ml, the remaining 93% had an average SCC of 276,000 cells/ml, a level comparable to international standards, well below the EU threshold of 400,000. The study also revealed that 98% of farmers considered milk quality as important or very important both to them and to the milk buyers. However, all farmers reported that they currently do not receive a milk-quality premium and are not penalized for poor quality. Seventy-nine percent of farmers reported the cooperative they belong to as their main source of information on management practices. An improved perception of milk quality both domestically and internationally will benefit Uganda’s dairy farmers and its dairy industry at large. Consumers must be assured that Uganda’s dairy industry, its government, industry stakeholders such as the Dairy Development Authority, the Uganda National Bureau of Standards, and the private sector place the utmost importance on the quality and safety of milk and other dairy products. New technologies to measure for SCC and strict food safety regulations will help improve the country’s milk-quality image, allowing Uganda’s dairy industry to tap into major milk export markets. Most developed countries have seen increased raw-milk quality or reduced SCC as a result of strong regulatory pressure.
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Schaeffer, Jeff R. "Southwestern Ohio Services: Small Business Consulting." Miami University Honors Theses / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=muhonors1115130315.
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Rischette, Alexander Curtis. "Gamebird Management in Southwestern North Dakota." Thesis, North Dakota State University, 2020. https://hdl.handle.net/10365/32040.
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Grassland biodiversity is threatened by habitat loss associated with human expansion. In response, land managers need to collect wildlife data more efficiently and implement management practices that promote wildlife habitat. To assess methods and land use practices for managing game birds in the Northwestern Great Plains, we quantified the behavioral response of sharp-tailed grouse (Tympanucus phasianellus) to small unmanned aerial systems (sUAS) exposure and measured production of upland nesting ducks on former Conservation Reserve Program land. We found survey altitudes ≥ 121 m above ground level and moderate wind speeds reduced behavior response of grouse. For waterfowl production, we found that nest survival increased with nest age, vegetation height, and relative humidity. Future sUAS application for grouse surveys should explore altitudes ≥121 m above ground level. In terms of duck production, we suggest land managers use practices that increase vegetation structure.
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Cameron, Catherine Margaret. "Architectural change at a Southwestern pueblo." Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185396.
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The architecture of the modern Hopi pueblo of Oraibi provides important data for the interpretation of prehistoric villages in the American Southwest and elsewhere. Using historic photographs, maps, and other documents, architectural change at Oraibi is examined over a period of almost 80 years, from the early 1870s to 1948, a span that includes an episode of population growth and a substantial and rapid population decline. Because archaeologists make extensive use architecture for a variety of types of prehistoric reconstructions, from population size to social organization, understanding the dynamics of puebloan architecture is important. This study offers several principals which condition architectural dynamics in pueblo-like structures in the Southwest and in other parts of the world. Four types of architectural change are identified at Oraibi: rooms were abandoned, dismantled, rebuilt, and newly constructed. Some changes were the result of the introduction of EuroAmerican technology and governmental policies. An increase in the rate of architectural change, especially new construction and rebuilding, suggests that population was increasing during the late 19th century. Patterns of settlement growth involved both the expansion of existing houses and the construction of new houses. Oraibi architecture, with contiguous rows of houses, may have restricted the development of extended families. After the 1906 Oraibi split, half the population left the village, and in the following decades, population continued to decline. Abandoned houses were often rebuilt and reoccupied by remaining residents. The number of rooms per house declined, especially upper story rooms. The areas of the settlement that continued to be occupied or were reoccupied were those around important ceremonial areas, such as the Main Plaza. The examination of architecture at historic Oraibi supplies links between social processes and architectural dynamics that are applicable to the prehistoric record. Patterns of intra-household architectural change and of settlement growth and abandonment, observed at Oraibi, provide keys to the investigation of similar processes at prehistoric sites.
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Trautman, Simon August. "Wet loose snow avalanching in Southwestern Montana." Thesis, Montana State University, 2007. http://etd.lib.montana.edu/etd/2007/trautman/TrautmanS0507.pdf.
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Wet loose snow avalanches are a significant hazard within many ski areas. Wet snow stability changes dramatically over short time periods which typically coincide with operating hours, and few quantitative tools exist for avalanche workers attempting to predict the onset of wet snow avalanching. Field work was conducted at two study sites in southwestern Montana during the springs of 2003, 2004, 2005, and 2006. The study is composed of three separate experiments. The first documents stratigraphic boundary conditions present during periods of wet loose instability. Results show that melt-water accumulation within the upper 15cm of the snowpack increases the likelihood of wet loose avalanche occurrence. The second focuses on the mean daily and minimum daily air temperatures, and how well each variable indicates wet loose avalanche activity. Results are consistent with prior research and clearly show that temperature alone is not a good indicator. The third relates wet loose snow avalanching to surficial shear strength. A 250cm² shear frame was used to make as many as 210 surficial shear strength measurements of melt-freeze snow per day. Changes occurred rapidly within the meltfreeze cycle as shown by highly significant changes in shear strength within half hour intervals. Most importantly, the data shows an apparent association between surficial shear strength and avalanche activity. When shear strength measurements dropped below 250 Pa wet loose avalanches were observed, and triggered, in the immediate vicinity of study slopes. Conversely, surficial stability on the study slope improved when shear strength values exceeded 250 Pa. This research provides insights into wet loose snow avalanching and the development of possible tools for better predicting wet loose snow avalanche occurrence.
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Edwards, Danielle L. "Biogeography and speciation of southwestern Australian frogs." University of Western Australia. School of Animal Biology, 2007. http://theses.library.uwa.edu.au/adt-WU2008.0058.
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[Truncated abstract] Southwestern Australia is a global biodiversity hotspot. The region contains a high number of endemic species, ranging from Gondwanan relicts to more recently evolved plant and animal species. Biogeographic models developed primarily for plants suggest a prominent role of Quaternary climatic fluctuations in the rampant speciation of endemic plants. Those models were not based on explicit spatial analysis of genetic structure, did not estimate divergence dates and may be a poor predictor of patterns in endemic vertebrates. Myobatrachid frogs have featured heavily in the limited investigations of the biogeography of the regions fauna. Myobatrachid frogs are diverse in southwestern Australia, and while we know they have speciated in situ, we know little about the temporal and spatial patterning of speciation events. In order to gain insight into the biogeographic history and potential speciation patterns of Myobatrachid frogs in the southwest I conducted a comparative phylogeography of four frog species spanning three life history strategies. I aimed to: 1) assess the biogeographic history of individual species, 2) determine where patterns of regional diversity exist using a comparative framework, 3) determine whether congruent patterns across species enable the development of explicit biogeographic hypotheses for frogs, and 4) compare patterns of diversity in plants with the models I developed for frogs. I conducted fine-scale intraspecific phylogeographies on four species. ... Geocrinia leai: deep divergences, coincident with late Miocene arid onset, divide this species into western and southeast coastal lineages, with a third only found within the Shannon-Gardner River catchments. Phylogeographic history within each lineage has been shaped by climatic fluctuations from the Pliocene through to the present. Arenophryne shows the first evidence of geological activity in speciation of a Shark Bay endemic. Divergence patterns between the High Rainfall and Southeast Coastal Provinces within C. georgiana are consistent with patterns between Litoria moorei and L. cyclorhynchus and plant biogeographic regions. Subdivision between drainage systems along the southern coast (in M. nichollsi, G. leai and the G. rosea species complex) reflect the relative importance of distinct catchments as refuges during arid maxima, similarly the northern Darling Escarpment is identified as a potential refugium (C. georgiana and G. leai). Divergences in Myobatrachid frogs are far older than those inferred for plants with the late Miocene apparently an important time for speciation of southwestern frogs. Speciation of Myobatrachids broadly relates to the onset of aridity in Australia in the late Miocene, with the exception of earlier/contemporaneous geological activity in Arenophryne. The origins of subsequent intraspecific phylogeographic structure are coincident with subsequent climatic fluctuations and correlated landscape evolution. Divergence within frogs in the forest system may be far older than the Pleistocene models developed for plants because of the heavy reliance on wet systems by relictual frog species persisting in the southwestern corner of Australia.
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Beckwith, Laurie Anne. "Late formative period ceramics from southwestern Ecuador." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq20725.pdf.
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Xu, Ben Xiaohui. "Regional flood frequency analysis for southwestern Alberta." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0019/MQ48072.pdf.
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Denton, Curtis James Oppong Joseph R. "Estimating Buruli ulcer prevalence in southwestern Ghana." [Denton, Tex.] : University of North Texas, 2007. http://digital.library.unt.edu/permalink/meta-dc-3981.
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Chen, Youhua. "Microarthropod diversity and distribution in Southwestern Canada." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44051.
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Microarthropod diversity patterns were investigated in southwestern British Columbia, Canada. We surveyed soil microarthropods associated with moss carpets on exposed rocky outcrops. Our survey identified 352 morphospecies in 32 sites spanning a 130 km 60 km area. Previous studies have interpreted strong correlations of species composition with environmental factors as evidence of niche limitation, and strong correlations with spatial factors as evidence of dispersal limitation. Here, we examine 18 ecological variables relevant to either spatial location or environmental aspects of ecological processes, and evaluate their influences on the microarthropod community. We tested whether the relative importance of spatial and environmental factors was concordant between various community attributes including composition, abundance and species richness, and between different taxonomic groups of microarthropods (Oribatida, Mesostigmata, Collembola). We used two different methods (distance-based Mantel and raw data-based ordination methods) to show that spatial variables could not explain composition or compositional turnover for most microarthropod groups, except Collembola. Dispersal limitation of Collembola is surprising given the high dispersal ability of this group. Although environmental factors explained a large amount of spatial variance in composition (raw data-based ordination method) for all microarthropod groups, environmental similarity (distance-based Mantel method) was a poor predictor of compositional similarity for Oribatida and Mesostigmata. Total abundance and species richness could also be explained by combinations of environmental factors, particularly those relating to tree cover and soil-relevant microhabitat variables (i.e, water content/mass, total soil mass and particle mass), but total abundance and richness were themselves only weakly correlated across space. The most important environmental influences on microarthropod communities were tree cover and water mass, followed by distance-to-sea. At the same time, there was a lot of unexplained variance in the composition of microarthropod communities (especially for species incidences) which could not be explained by the available ecological variables. As richness hotspots were dispersed across different habitats for different taxonomic groups, we suggested that species interactions might be equally important as environmental filtering and spatial autocorrelation in shaping microarthropod community structure, especially for patterns in species incidence.
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McPherson, E. Gregory. "Southwestern Landscaping that Saves Energy and Water." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/144823.
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62 pp.Illustrated guidelines for energy and water conservation for landscaping in the southwestern area of the United States, along with the landscaping design process.Includes appendix on tree, shrub and vine characteristics and requirements. (62 pages.)
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Jullion, Loĭc. "Water mass modification in the southwestern Atlantic." Thesis, University of East Anglia, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446168.
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Adebayo, Adebisi. "Reproductive decision making in Ibadan, southwestern Nigeria." Thesis, University of Liverpool, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.425455.
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Allen, Roger Scott. "Cyberbullying in Middle Schools in Southwestern Virginia." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/83420.
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Cyberbullying is an alarming phenomenon affecting the lives of adolescents across the country. Traditional bullying has moved from the playground to cyberspace. This online environment allows perpetrators to attack their victims beyond the walls of school, twenty-four hours a day. Advancements in and access to technology have made electronic communication the preferred method for adolescents to socialize. Although email, texts, social media sites, and websites were created to ease communication, some adolescents are using these tools to harass and harm their peers.
The purpose of this study was to gain a deeper understanding of the existence and prevalence of Cyberbullying in middle schools across Region VII in southwest Virginia. Cyberbullying policies and strategies used to address Cyberbullying were examined. The experiences of middle school principals with Cyberbullying incidents were explored.
The aim of this study was to address the following three research questions:
1. What is the status of Cyberbullying in Region VII of southwest Virginia?
2. What are middle school principals' perspectives regarding their schools' effectiveness in responding to Cyberbullying?
3. What are middle school principals' recommendations to strengthen Cyberbullying policies and procedures?
A quantitative method was chosen and a survey was conducted with the goal of adding to the literature that existed on Cyberbullying in public schools. Through the development and administration of a survey, quantitative data was collected. A quantitative analysis was conducted using descriptive statistics.
The study adds to the current empirical research base on Cyberbullying in middle schools, especially in the rural area of a state. The perceptions of principals working in middle schools are valuable. This study tapped into this knowledge base and added to the literature on Cyberbullying by providing insights into the feelings and perceptions of administrators. Analyzing the experiences of the participants provided valuable information for those interested in learning more about Cyberbullying in middle schools in southwest Virginia.
Findings of the study include information for Region VII of southwest Virginia on the status of Cyberbullying, middle-level schools' effectiveness in responding to Cyberbullying, and principals' recommendations to strengthen Cyberbullying policies and procedures. Based on the survey results, it is clear that Cyberbullying existed within the school systems in the region. Cyberbullying incidents occurred both at school and away from school. The largest percentage of these incidents occurred in the seventh and eighth-grades. Survey data indicated gender played a role in Cyberbullying with female students having the most reported incidents. Bullying prevention programs were being implemented in most school systems and schools in this region, and, in some cases, Cyberbullying was specifically addressed. In school systems and schools where no bullying or Cyberbullying prevention programs were implemented, overwhelmingly, principals felt they should be. Data revealed most principals found it difficult to identify Cyberbullying instances but believed they did report Cyberbullying incidents consistently. Most principals felt their school system's Cyberbullying policies were effective in dealing with Cyberbullying incidents, that the policies did not need revision, and that no additional policies were needed. Most principals felt Cyberbullying consequences implemented at their school effectively deterred Cyberbullying. Three strategies were identified by more than fifty percent of principals that would help in deterring Cyberbullying incidents. These strategies were increased parental involvement, encouraging students to report Cyberbullying, and anti-bullying education.Ed. D.
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Randriamahefasoa, Tsinampoizina Marie Sophie. "Variability of summer rainfall over southwestern Madagascar." Master's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/9809.
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Includes bibliographical references.This study investigates the interannual variability of the frequency of wet days during the rainy season over southwestern Madagascar, and its associated regional and global circulation patterns. The number of wet days was counted for each summer season (December to March) of the period 1971 to 2000 at four rainfall stations in southwestern Madagascar. For each station, the frequency of wet days was correlated with ENSO indices, SIOD index, SST, 850 hPa geopotential height, zonal and meridional winds at the surface. Composite anomalies of moisture flux and moisture flux convergence at 850 hPa, 500 hPa omega and velocity potential at .995 sigma level, using NCEP/NCAR reanalysis data, associated with El Niño events, La Niña events that occurred during the period of study were examined. Also, circulation anomalies during neutral years having anomalously high frequency of wet days or anomalously low frequency of wet days were analysed separately. It was found that the number of wet days rarely exceeds half of the total days in summer for each station. Inverse relationship between the equatorial Pacific SST anomalies and the frequency of wet days anomalies was identified. Statistics showed that years characterised by high frequency of wet days often occur with La Niña seasons whereas years having low frequency of wet days tend to occur with El Niño seasons. A strong relationship between the southern Indian Ocean SST and the frequency of wet days was found at Ranohira (45.3° E, 22.5° S) and Toliara (43.72° E, 23.38° S). Increased number of wet days over southwestern Madagascar is associated with low atmospheric pressure over the southern Mozambique Channel. Neutral years having anomalously high (low) frequency of wet days are marked by northwesterly (southeasterly) moisture flux anomalies at 850 hPa over southwestern Madagascar.
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Sebastian, Andrea Michelle. "Consulting a Small Business: Southwestern Ohio Services." Miami University Honors Theses / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=muhonors1115129808.
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Denton, Curtis James. "Estimating Buruli Ulcer Prevalence in Southwestern Ghana." Thesis, University of North Texas, 2007. https://digital.library.unt.edu/ark:/67531/metadc3981/.
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Mycobacterium ulcerans is sweeping across sub-Saharan Africa, but little is known about the mode of transmission and its natural reservoirs. Since the only effective treatment is excision of the infection and surrounding tissue, early diagnosis and treatment is the only way to reduce the havoc associated with Buruli ulcer. Using data from a national case search survey conducted in Ghana during 2000 and suspected risk factors this study tests the hypothesized factors and probes the challenges of developing a spatial epidemiological regression model to explain Buruli ulcer prevalence in the southwestern region of Ghana representing 42 districts. Results suggest that prevalence is directly related to the degree of land cover classified as soil, elevation differential, and percent rural population of the area.
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Bold, Uyanga. "Neoproterozoic to Paleozoic Geology of Southwestern Mongolia." Thesis, Harvard University, 2016. http://nrs.harvard.edu/urn-3:HUL.InstRepos:33493509.
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The Neoproterozoic and Paleozoic evolution of global climate, tectonics, ocean geochemistry, and biological diversification are recorded in stratigraphic successions globally. The rock record of southwestern Mongolia has potential to reveal additional constraints as it is in the early stages of exploration. It has been known for several years that Cryogenian passive margin sedimentation on the Zavkhan Terrane hosts evidence for Neoproterozoic glaciation, and that overlying early Cambrian strata host rich records of small shelly fossils; however, the geological context for these critical records has been previously lacking.
Although these unknowns can be regarded as local geologic uncertainties, together they hold implications to test existing tectonic and crustal growth models of the Central Asian Orogenic Belt (CAOB), preservation potential of geochemical proxies within carbonate dominated strata, and biologic milestones as recorded in Paleozoic sediments. To understand and interpret the above implications, methods of field geology, litho- and chemo-stratigraphy, geochemistry, petrography, fluid inclusion and clumped isotope thermometries, and U-Pb zircon geochronology were used.
As a result, the tectonic origin and travels of the Zavkhan Terrane during the Neoproterozoic to early Paleozoic is refined and models of apparent crustal growth in the CAOB are re-assessed. Global Cryogenian and Ediacaran carbon and strontium isotope curves are constructed from limestonedominated successions of the Tsagaan-Olom Group of the Zavkhan Terrane and are integrated with available geochronologic and geochemical data from around the globe. Finally, dolomitization is shown to greatly alter primary geochemical signatures, including carbon isotope values of carbonate rocks.Earth and Planetary Sciences
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Stuckey, David A. "Biogeochemical Survey of Wetlands in Southwestern Indiana." [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0012782.
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Cook, Barbara J. "Women's transformative texts from the Southwestern Ecotone /." view abstract or download file of text, 2003. http://wwwlib.umi.com/cr/uoregon/fullcit?p3095241.
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Thesis (Ph. D.)--University of Oregon, 2003.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 161-179). Also available for download via the World Wide Web; free to University of Oregon users.
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Weber, Matthew August. "Riparian Valuation in the Southwestern United States." Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/195121.
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This research documents the societal worth of riparian resources in the Southwestern United States. Two case studies are developed for this inquiry, the first being Aravaipa Canyon Wilderness in Southern Arizona, an area containing one of the last perennial streams in the Sonoran Desert bioregion. A hiking use value per visitor-day is estimated via the Travel Cost Method at $25.06 and $17.31 (2003 dollars) respectively for two access sites. I hypothesize the value discrepancy to indicate a premium for remote recreation. These valuation results compare well with other published recreational use value estimates, though it is the only valuation study associated with instream recreation in the Sonoran Desert of which I am aware. Indeed the environmental valuation literature is thin for the desert region in any respect.The second case study values public restoration preferences for the Albuquerque reach of the Rio Grande in Central New Mexico. A Choice Experiment and Contingent Valuation are employed within an original survey instrument to estimate human values for various restoration strategies planned for the region. Through focus groups and stakeholder interactions four restoration attributes were defined: vegetation density; tree type; fish and wildlife population; and natural river processes. Quantified values for Albuquerque area households were estimated for each restoration attribute level of change, allowing construction of total benefits anticipated for various restoration scenarios considered for the region. This research is at the vanguard of quantifying human benefit for saltcedar control, and this particular restoration characteristic was the most highly valued of all, at $59.03 per household per year. Full restoration was valued at $156.60 per household per year. These results have meaning beyond the study area since river restoration efforts are increasing across the Western US, with many focusing on controlling saltcedar, an exotic invasive plant.The final phase of this research integrates riparian valuation concepts within a dynamic simulation framework to guide systems-level riparian management. Control variables are combined with known valuation pathways to predict riparian investment funding optimal in benefit-cost ratio. The model is built for the Middle Rio Grande in Albuquerque, however it was designed for easy adaptation to other Southwestern riparian areas. A detailed forest module is included, through which seven defined forest stocks may be managed through thinning, clearing, and revegetation. River management may occur through environmental river flow releases, reconstructing stream-overbank connections, and wetland construction. Recreational amenities may be improved through the four infrastructure categories of trails, toilet facilities, picnic areas, and parking areas. Benefits and costs are estimated through original research and region benefit transfer, and tracked for different investment scenarios to predict the highest-return strategies over a 100 year planning horizon. A sensitivity analysis is used to suggest areas of future research.
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Brodhead, Katherine May. "The influence of riparian-canopy structure and coverage on the breeding distribution of the southwestern willow flycatcher." Thesis, Connect to this title online Connect to this title online (alternative address), 2005. http://www.montana.edu/etd/available/brodhead%5F0805.html.
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Thesis (M.S.)--Montana State University--Bozeman, 2005.Title from PDF t.p. (viewed on June 10, 2006). Chairperson, Graduate Committee: Richard J. Aspinall. Includes bibliographical references (p. 93-105).
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Loo, Christopher. "The ecology of naturalised silvergrass (Vulpia) populations in south-western Australia." University of Western Australia. School of Plant Biology, 2005. http://theses.library.uwa.edu.au/adt-WU2005.0093.
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[Truncated abstract] Annual grasses have colonised a diverse range of environments in southern Australia. The “Silvergrasses” of the genus Vulpia are excellent examples being widely distributed, are prevalent weeds of agriculture and have had a long history to naturalise on the continent. Research was undertaken on Vulpia populations to identify if naturalising species have reproductive traits that provide propagules with the best chances of success. Furthermore, research aimed at investigating if these traits vary between species and their populations and how this variability related to the environment. A herbarium and field study was undertaken to establish what Vulpia species occur in SW Australia and to investigate environmental factors affecting their distribution. 169 herbaria specimens was examined and a botanical field survey of 189 sites was carried out in September 1998. Four species occur in the region: V. fasciculata, V. muralis, V. bromoides and two variants of V. myuros (V. myuros var. megalura and V. myuros var. myuros). V. bromoides and V. myuros were introduced early into the region while V. fasciculata and V. muralis more recently. It is plausible that Vulpia invaded the region via early seaport settlements and was spread by agricultural expansion. 96% of field sites contained V. myuros var. myuros, 79% V. myuros var. megalura, 50% V. bromoides, 6% V. fasciculata and 6% contained V. muralis. 90% of sites contained a mix of species and 9% of sites contained pure species stands. V. myuros var. myuros is the most widespread species and dominant form of V. myuros. It is found from high rainfall regions through to arid locations occurring on mostly light textured low fertility soils. V. muralis and V. fasciculata occur infrequently with the former widely dispersed and the later occurring predominantly on sands. V. bromoides occurs extensively in high rainfall regions but rarely extends to locations receiving less than 400-450mm annual rainfall and northward above 30°00’ latitude. It is predominantly on light to loamy textured soils that are fertile and acid. The most common species V. myuros and V. bromoides often coexist within sites but the dominance of one over the other is strongly correlated with growing season length and false break frequency. V. bromoides is positively correlated to growing season length and V. myuros is negatively related. The distribution of Vulpia species is strongly influenced by climate and soils. Variability in distribution is a reflection of the ecological differentiation between species to colonise different environments
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Buvit, Ian. "Geoarchaeological investigations in the southwestern Transbaikal region, Russia." Online access for everyone, 2008. http://www.dissertations.wsu.edu/Dissertations/Spring2008/i_buvit_042108.pdf.
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Corriveau, Louise. "Potassic alkaline plutonism in the southwestern Grenville Province." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74275.
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Ultrapotassic, potassic alkaline and shoshonitic magmatism with subduction-related affinity co-existed in a Proterozoic (1089 to 1076 Ma) plutonic environment: the SW Grenville Province. The stocks have silica-saturated and undersaturated, felsic-to-ultramafic units emplaced diapirically in separate, progressively more mafic batches of magma. Most magmas crystallized in situ, and were saturated in apatite, biotite and clinopyroxene. Fractionation of these minerals from a single parental mafic magma is ruled out as the fractionation process prior to emplacement during which Ba, Sr, Nb and Zr were incompatible. Felsic magmas in endoskarns have been contaminated by marble. The paragenesis, the primary LILE, Ca and Al enrichment, and depletion of Nb and Ta typical of ultrapotassic rocks of island-arc, the NE-trend and SE-younging of this belt suggest active NE-trending, SE-dipping subduction during this episode of magmatism and are used to delimit allochthonous terranes.
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Siegel, Richard S., and John H. Brock. "Germination Requirements of Key Southwestern Woody Riparian Species." University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/609112.
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Germination requirements of selected Southwestern woody riparian species were studied in the laboratory. Four common tree species selected for study were Fremont Cottonwood (Populus fremontii), Goodding Willow (Salix gooddingii), Arizona Sycamore (Platanus wrightii) and Velvet Mesquite (Prosopis velutina). Seeds were collected from two major riparian habitats in the southwest. The species tested required a temperature range of 16° C to 27° C for germination. Fremont Cottonwood, Goodding Willow and Velvet Mesquite showed good germination at moisture stress levels of -4 bars or less, whereas Arizona Sycamore only germinated well at 0 bars. For all species tested, germination was better at salinity levels lower than 50 meq /liter NaCl. All species displayed successful germination responses between pH 5 to 7. Velvet Mesquite germinated at all pH levels (5 -10). Longevity of seeds of riparian species is reported to be of short duration. This was confirmed in these studies with southwestern woody riparian species.
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Pope, Dennis P., John H. Brock, and Ralph A. Backhaus. "Vegetative Propagation of Key Southwestern Woody Riparian Species." University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/609140.
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A series of laboratory and greenhouse experiments were designed with the objective of determining effective methods of vegetatively propagating selected woody riparian species for use in restoration of Southwestern riparian habitats. Cuttings from four major southwest riparian species including Fremont Cottonwood (Populus fremontii), Goodding Willow (Salix gooddingii), Arizona Sycamore (Platanus wrightii), and Arizona Walnut (juglans major) were collected along the Gila River in western New Mexico. Propagation studies with hardwood and root cuttings were performed. Results from these studies determined that Fremont Cottonwood and Goodding Willow could be readily propagated from dormant stem cuttings. Nodal explants from the laboratory -grown Arizona walnut seedlings were tissue -cultured in order to develop a method to mass produce this difficult to propagate species. A nutrient and hormone solution was formulated that resulted in shoot proliferation of Arizona walnut explants in vitro.
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Li, Lan. "Nuo : shamanism among the Tujia of southwestern China." Thesis, Queen's University Belfast, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263402.
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Hesch, Lindsey Elizabeth. "Community dynamics in an experimental southwestern Ohio prairie." Miami University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=miami1185993065.
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Heineman, Rachel. "Glaciovolcanic megapillows of Undirhliðar, Reykjanes Peninsula, southwestern Iceland." Oberlin College Honors Theses / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=oberlin1497742380067619.
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Kumble, Peter Andrew 1957. "The vernacular landscape of the southwestern guest ranch." Thesis, The University of Arizona, 1992. http://hdl.handle.net/10150/291844.
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The western guest ranch evolved out of an era when American literature, film, and radio romanticized the cowboy and his landscape as symbols of the frontier west. As with architectural style, landscape imagery was a powerful tool in conveying social trends. Research briefly details the evolution of the dude ranch and its development in southeastern Arizona. Specific area of study is the San Simon and Sulphur Springs Valley of present day Cochise County, Arizona. A brief history of the region's settlement is provided. The location, landscape, facilities, and entertainment of eight guest "dude" ranches in the study area is described. A detailed examination of Faraway Ranch is provided, including site plans, photographs, and inventory of existing vegetation. The vernacular landscape of the southeastern Arizona guest ranch is identified. Reasons for the appeal of a guest ranch and its landscape to patrons is described.
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Kechum, Lynn G. "The Boyce Thompson Southwestern Arboretum: A Garden Oasis." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/295520.
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Robinson, D. Lowell, and Albert K. Dobrenz. "Horticultural Survivors of a Southwestern Arizona Ghost Town." University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/554239.
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Suntsov, andrei V. "New Data on Ichthyoplankton of the SouthWestern Pacific." W&M ScholarWorks, 1997. https://scholarworks.wm.edu/etd/1539617727.
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Dolling, Perry. "Lucerne (Medicago sativa) productivity and its effect on the water balance in southern Western Australia." University of Western Australia. Faculty of Natural and Agricultural Sciences, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0108.
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[Truncated abstract] In southern Western Australia the replacement of deep-rooted native vegetation with annual species has resulted in rising water tables and increased salinity due to insufficient water use. The area has a Mediterranean-type climate where rainfall during summer is generally low but variable resulting in limited plant growth. However, if rainfall does occur it potentially can contribute to to the increased water excess or drainage by increasing the soil water content before the main drainage period in winter. The first study investigated factors controlling soil water content changes during the fallow (December to May) in annual farming systems. This was achieved by examining variation in available soil water storage to a depth of 1.0-1.5 m at three sites within 13 seasons. Reasons for the variation were examined using the Agricultural Production Systems Simulator (APSIM). This study also investigated the relationship between soil water content at the end of the fallow period (1 May) and the amount of drainage below 2.5 m by using APSIM coupled to historical weather records at three locations. At the end of the fallow a mean of 24 mm (or 25%) of rainfall during the fallow was retained in the soil. Losses of soil water during the fallow were due to evaporation (mean of 60 mm), transpiration from plant cover (mean of 12 mm) and drainage below the root zone and run off (combined mean of 13 mm). Soil water accumulation during the fallow period had a significant impact on simulated drainage under wheat in the following growing season. Every 1 mm increase in soil wetness at the end of the fallow resulted in a 0.7-1 mm increase in simulated drainage during the growing season. ... Variation in the water excess due to variation in rainfall was greater than the reduction in water excess due to lucerne. This makes the decisions about when to grow lucerne to reduce water excess difficult if livestock enterprises are less profitable than cropping enterprises. The findings of this PhD indicate that lucerne does have a place in Mediterranean-type environments because of its greater water use than current farming practices. However, its use needs to be strategic and the strategy will vary from region to region. For example, in the low rainfall region lucerne sowings need to be matched with high soil water contents and phase length will generally be short (2-3 years). In comparison at high rainfall regions lucerne will need to be grown for longer or combined with other strategies to increase water use.
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Olovsson, Anders. "Habitat selection by moose (Alces alces) in southwestern Sweden." Thesis, Karlstad University, Faculty of Social and Life Sciences, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-1033.
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The moose (Alces alces) is very important both economically and ecologically, therefore all knowledge of moose is vital for future management of the moose population. Little is known about moose habitat selection in Sweden. In coastal southwestern Sweden growing human population and new infrastructure projects continuously threaten to fragment and isolate local moose populations. The habitat selection of 22 moose, 8 males and 14 females, in southwestern Sweden was studied from February 2002 until December 2005. The moose were captured and fitted with GPS-collars and positions were collected at 2-hour intervals. The number of moose positions totaled 71103 during the study period of 46 months. Data for individual animals were divided into four seasons: spring, summer, fall and winter based on climate and moose biology. A total of 125 moose seasonal home ranges were generated and habitat use within each of the generated home ranges was studied using Euclidean distance-based analysis. A reclassified digital landcover map was divided into the land use classes agriculture, clear-cut, coniferous forest, deciduous forest, mire and mountain. The results showed that there was a difference in habitat selection between males and females. Males were significantly closer to forest and clear-cuts compared to females. Both males and females selected clear-cuts and avoided agriculture within their home ranges.
Älgen är en viktig art, både ekonomiskt och ekologiskt, och all kunskap är viktig för att även i framtiden kunna sköta en sund älgstam. Trots flertalet studier finns det många frågetecken om älgens habitatval i Sverige. En ökad exploateringstakt och nya infrastrukturprojekt hotar att fragmentera och isolera populationer av älg. Habitatvalet hos 22 älgar, 8 tjurar och 14 kor, i sydvästra Sverige studerades mellan februari 2002 och december 2005. Älgarna sövdes och utrustades med GPS-sändare, deras positioner registrerades varannan timma och det totala antalet positioner under den 46 månader långa studietiden var 71103 stycken. Data från varje älg delades in i 4 säsonger; vår, sommar, höst och vinter, baserat på klimat och älgens biologi. Totalt genererades 125 hemområden baserade på säsong, och valet av habitat inom varje hemområde studerades med hjälp av Euclidean distance-based analysis. En omklassificerad digital marktäckedata användes som var indelad i 6 olika klasser; odlad mark, hygge, barrskog, lövskog, myrmark och berg i dagen. Resultaten visade att det var skillnad mellan könen i hur de väljer habitat. Tjurarna var signifikant närmare barrskog och hyggen än korna, men både tjurar och kor selekterade för hyggen och undvek odlad mark inom deras hemområden.
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Reddy, Douglas Gerald. "Geology of the Indian River area, southwestern British Columbia." Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/27624.
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The Britannia - Indian River pendant is a composite of volcanic and sedimentary units within the Coast Plutonic Complex, southwestern British Columbia. Geology of the Indian River valley consists of a rhyolitic to basaltic calc-alkaline suite of volcanic flows and tuffs interbedded with shallow marine sedimentary rocks. The pendant is within Wrangellia and has been assigned to the Gambier Group of Late Jurassic to Early Cretaceous age.
K-Ar analyses indicate three major thermal events took place in the Britannia -Indian River pendant: (1) a late Early Cretaceous contact metamorphism (108 ± 4 Ma), (2) an early Late Cretaceous regional metamorphic reset associated with emplacement of granitoid plutons (96.1 ± 3.0 Ma, 95.6 ± 3.3 Ma), and (3) a Late Cretaceous (83.5 ± 3.0 Ma, 84.2 ± 2.9 Ma) metamorphic reset due to a deformational and/or intrusive event. A poorly defined whole rock Rb-Sr isochron from seven fresh-looking volcanic units indicates a 102 ± 10 Ma age that also probably reflects metamorphic reset. An internal Rb-Sr isochron comprising partial mineral separates from one sample yielded 93 ± 3 Ma, which supports the regional metamorphic reset.
Younger dykes and sills are dated as Early Oligocene (36.1 ± 1.3 Ma). These Tertiary intrusives are the same age as dykes in the city of Vancouver and indicate a more widespread magmatic event than previously recognized.
The stratigraphic section in the Indian River and Stawamus River valleys consists of more than 2,850 metres, and comprises seven units that trend northwesterly and dip moderately south or southwest. A change in the overall strike from northwest in the Indian River valley to west in the Stawamus Valley suggests either: (1) an angular unconformity within unit 4a, (2) the existence of a major shear zone in the Stawamus River valley, or (3) warping of the strata due to emplacement of the plutonic bodies. The stratigraphy in the Indian River area forms the western limb of a broad northwesterly trending antiform, overturned to the northeast. Along the Indian River a smaller anticline has been disrupted by several faults. These northwest trending faults are the northern extension of the Indian River shear zone.
The stratigraphic units are mainly subaqueous felsic to intermediate pyroclastic rocks, felsic and intermediate to mafic flows, and sedimentary rocks including cherts, argillites and greywackes. Major and trace element chemistry of volcanic units indicates the calc-alkaline rocks are dominantly rhyolite and basaltic andesite. Mafic units on Sky Pilot Mountain have a "borderline" tholeiitic - calc-alkaline character.Late Cretaceous lower greenschist facies metamorphism is related to emplacement of Coast Plutonic Intrusives. Intense cordierite-biotite contact metamorphism post-dates mineralization in the Slumach zone: a polymetallic quartz-chlorite vein with anomalous gold values. The War Eagle zone is a low grade volcanogenic system containing remobilized sulphides. Galena lead isotopic analyses of volcanogenic prospects in the Indian River valley are uniform and are less radiogenic than those of the Britannia volcanogenic ore bodies 10 kilometres to the west. The Indian River portion of the Britannia - Indian River pendant is proposed to be Late Jurassic in age while the Britannia area is Late Jurassic to Early Cretaceous.Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
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Doran, Bruce R. "The macroinvertebrate community of vernal pools in southwestern Quebec." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ55048.pdf.
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Ness, Ryan. "Evaluation of natural channel design applications in southwestern Ontario." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ61935.pdf.
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Sager, Melissa L. "Petrologic study of the Murrysville sandstone in southwestern Pennsylvania." Morgantown, W. Va. : [West Virginia University Libraries], 2007. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5538.
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Thesis (M.S.)--West Virginia University, 2007.Title from document title page. Document formatted into pages; contains ix, 90 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 83-87).
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Doran, Bruce R. "The macroinvertebrate community of vernal pools in southwestern Québec /." Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=29883.
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Temporary snowmelt pool ecosystems in southwestern Quebec were examined with special emphasis on identifying the macrofauna and determining their spatial distribution, as well as ascertaining temporal changes in community composition. 68 taxa were collected from ten snowmelt pools. Major taxa represented were Diptera, Coleoptera, Hemiptera, Trichoptera, Odonata, Ephemeroptera, Anostraca, Isopoda, Amphipoda, Gastropoda and Bivalvia; the insects dominated the communities and the Culicidae (Diptera) was the most abundant taxon collected. The fauna were unevenly distributed both spatially and temporally amongst the pools. The occurrence of taxa was similar in pools in the same geographic location. The habitat characteristics of each pool, coupled with their proximity to a permanent waterbody and their accessibility to organisms, perhaps influenced the distribution of the various taxa. A successional pattern was observed in which filter-feeders and detritivores appeared first, followed by predators. After drought, a similar pattern was seen in pools that were replenished by summer rains, but taxon diversity was lower. In addition, pools with longer hydroperiods harboured more taxa than shorter-lived pools.
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Jaria, Felix. "Irrigation scheduling strategies for tomato production in Southwestern Ontario." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=116875.
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Precision irrigation scheduling is critical to improving irrigation efficiency. It is a combined technical and managerial tool that determines accurately when, how much and how often irrigation is applied to meet optimum crop response. This is particularly challenging in humid regions such as Southwestern Ontario, where soil moisture is often influenced by periodic rainfalls. The overarching goal of this three year research project was to investigate different irrigation scheduling strategies for tomato production in Leamingtion, Ontario. There were four specific objectives. The first sought to develop an optimum irrigation schedule for intensive cultivation of processing tomatoes by examining different irrigation trigger levels. Moisture triggers were expressed as a fraction of field capacity and soil tension, which are also related to soil available water content (AWC). Triggers with moisture depletion levels of ≤ 40 % (AWC) produced the higher yields. However, the best yields were obtained from the tension treatment with an upper and lower moisture threshold of -10 kPa and -30 kPa, which represented 20 to 24% depletion in AWC.The second objective sought to develop a robust protocol for implementing an irrigation scheduling. Three different types of soil moisture sensors were evaluated. The tension based senor emerged with the highest evaluation score. However, all three sensors could be used to effect irrigation scheduling. The sensor based irrigation data was subsequently compared with the Peman-Monteith model. It was found that the soil moisture treatments with a moisture depletion level of ≤ 40 % soil available water content (AWC) adequately met crop water requirements throughout the season.The third objective examined the spatio-temporal variability of soil moisture under drip irrigation in a controlled greenhouse environment. The study indicated that soil moisture content was not uniformly distributed prior to or after an irrigation event. For double row planting of tomatoes with a central drip line, a row spacing of 50 cm was adequate for planting of seedlings, due to the higher soil moisture contents within that zone. Further, due to the lack of uniform distribution of moisture in the soil profile, paired sensors (with one either side of the drip line) can provide a better estimate of soil moisture depletion for sensor based irrigation scheduling.The fourth objective investigated the nutrient dynamics along the soil profile over the growing season. Soil nutrients (P and N) were monitored at three different levels of the profile (0 to 30, 30 to 50 and 50 to 70 cm) and at the pre-planting, mid-season and end of season stages. Statistical significance in Olsen P and NO3-N was obtained both across the season and along the profile for each of the three years. The variability among treatments was not significant. The P and N concentrations at the 50 to 70 cm depths were found to be high, with the potential of being leached through the subsurface drainage system. A modification in the application of P and N can help reduce leaching of nutrients below the rooting zone. This would necessitate a split application of P and more frequent application of liquid N in smaller quantities.La planification précise de l'irrigation est critique à l'amélioration de son rendement. C'est un outil technique et de gestion qui permet d'évaluer avec précision la quantité et la fréquence d'application de l'irrigation afin de répondre à la demande pour une croissance optimale des cultures. Cette planification est particulièrement difficile dans les régions humides, comme celles du sud-ouest ontarien, où l'humidité des sols est influencée par des pluies périodiques. Le but fondamental de ce projet de recherche de trois ans était d'étudier les différentes stratégies de planification de l'irrigation pour la production de tomates à Leamington, Ontario. Il y a eu quatre objectifs spécifiques. Le premier a visé à développer une planification optimale de l'irrigation pour des conditions intensives de culture de la tomate destinée à la transformation en examinant différents facteurs déclencheurs pour l'irrigation. Le taux d'humidité, comme élément déclencheur, a été exprimé par une fraction de la capacité au champ et de la succion du sol, qui sont reliés à la réserve utile (RU) d'eau du sol. Le dispositif de déclenchement avec un appauvrissement en eau de ≤ 40% (RU) a produit les meilleurs rendements. Les meilleurs rendements ont été obtenus lors d'une tension entre les seuils critiques supérieur et inférieur d'humidité de -10 kPa et -30 kPa, ce qui représentait un appauvrissement de 20 à 24% de la RU. Le second objectif a visé le développement d'un protocole robuste pour la mise en opération d'une planification du calendrier d'irrigation. Trois différents types de capteurs de l'humidité du sol ont été évalués. Le capteur basé sur la mesure de succion est sorti gagnant avec la plus haute note d'évaluation. Cependant, les trois capteurs peuvent être utilisés avec succès pour le contrôle du calendrier d'irrigation. Les données obtenues lors de l'irrigation contrôlée par les capteurs ont été comparées avec le modèle de Peman-Monteith. Il a été démontré que les niveaux d'humidité du sol qui ont assuré un appauvrissement en eau de ≤ 40% de la réserve utile (RU) du sol en eau ont permis de remplir les besoins en eau des cultures tout au long de la saison. Le troisième objectif a examiné la variabilité spatio-temporelle de l'humidité du sol lors de l'irrigation au goutte-à-goutte dans une serre à environnement contrôlé. L'étude a montré que l'humidité du sol n'était pas distribuée uniformément et ce avant, comme après l'irrigation. Dans le cas des tomates de champ avec une ligne centrale de goutte-à-goutte, un espacement de rangée double de 50 cm fut adéquat pour le semis des jeunes pousses, grâce au plus haut taux d'humidité du sol dans cette zone. De plus, avec le manque d'uniformité de la distribution de l'humidité dans le sol, des capteurs jumelés (placés de chaque côté de la ligne goutte-à-goutte) pourraient donner une meilleure estimation de l'appauvrissement en eau du sol pour une meilleure programmation de l'irrigation contrôlée par capteur. Le quatrième objectif a étudié la cinétique des éléments nutritifs à travers le profil du sol tout au long de la saison de culture. Les éléments nutritifs du sol (P et N) ont été surveillés à différents niveaux du profil (0 à 30, 30 à 50 et 50 à 70 cm) et au moment précédant le semis, en mi-saison et en fin de saison. La signification statistique de P et N a été obtenue tout au long de la saison et selon le profil du sol et ce pour les trois années de l'étude. La variabilité entre les traitements n'a pas été significative. Les concentrations en P et N aux profondeurs de 50 et 70 cm se sont avérées élevées, avec un potentiel d'être emportées par le système de drainage souterrain. Une modification de l'application de P et N peut aider à réduire le lessivage du sol sous la zone racinaire.
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Fonseca, Joāo F. B. Duarte. "Seismicity and regional tectonics of the Estremadura, Southwestern Portugal." Thesis, Durham University, 1989. http://etheses.dur.ac.uk/6644/.
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The RESTE Project was an integrated geophysical-geological study of the Estremadura, southwestern Portugal. The core of the programme consisted of the acquisition and analysis of microearthquake data. This was complemented by an investigation of the structural evolution of the sedimentary basins of the Estremadura. The geological evolution of the Lusitanian Basin was strongly marked by the reactivation of Palaeozoic basement faults, in response to a sequence of tectonic events: opening of the Central Atlantic, opening of the North Atlantic and Alpine convergence between Africa and Eurasia. The current tectonics are regarded as a subdued continuation of the Miocene deformation (Betic Orogeny), and the "tectonic memory" revealed by the Lusitanian and Lower Tagus Basins is explored to characterize the current tectonic processes. Strike-slip tectonics are identified as a dominant feature of several stages of the evolution of the basins, with particular relevance during the Miocene. The technique of "backstripping" is applied to well data, to constrain the history of vertical movement in the basins. This analysis highlighted the pre mature truncation, in the Late Jurassic, of a normal passive-margin evolution. Tectonic unstability caused the structural inversion of areas within the basins, and seems to have inhibited the predictable thermal subsidence. The rifting process, initially taking place at the Lusitanian Basin, jumped westwards in the Late Jurassic. Crustal underplating and the activity of transfer faults are in-voked as possible explanations for the subsequent deformation of the aborted rift. An upper-plate margin configuration is in good agreement with several observations. The tendency for structural inversion continued throughout theCretaceous, and with the onset of the Alpine convergence in the Turonian the control of the tectonic activity seems to have switched from the Atlantic to the Mediterranean. This reinforced the tectonic unstability, marked by magmatic activity and by a regional upwarp that was to last until the Eocene. Of particular interest was the behaviour, during the Late Cretaceous, of the Setúbal Peninsula sub-basin, which seems to have tilted towards the NW as a block, with a hinge line along the present Lower Tagus Valley. When sedimentation was resumed in the Eocene, a pattern of differential vertical movement was established, with some areas continuing to undergo inversion while nearby areas subsided. This pattern characterized the Cainozoic evolution of the basins, and probably still applies to the neotectonic deformation. The activity of strike-slip basement faults, reactivated under the compressive regime caused by the Afro-Eurasian conver-gence, is proposed as the best explanation for the Miocene deformation, with particular relevance for the Lower Tagus Valley. The RESTE Microearthquake Survey is described, and the data acquired with the RESTE network are analysed. The local earthquakes are accurately located, and focal mechanism solutions are obtained for some of them. This information is used to discuss a neotectonic model for the Lower Tagus Valley. In view of their small magnitudes (l.1< M(_L) < 3.8), the focal mechanisms of these events cannot be interpreted directly in terms of the current tectonics. Such small events are usually local readjustments to previous episodes of deformation. However, such features as the along-strike reversal of the polarity of vertical motion or the coexistence at the same region of different types of source mechanism are diagnostic of strike-slip deformation. This model was supported by the occurrence of a macroearthquake (M(_D)=3.8) with an interpreted source mechanism of sinistral strike-slip. The alignment of four hypocentres along the direction of the Lower Tagus Valley, with a compatible orientation of the interpreted nodal planes, supports the existence of a crustal fracture associated with the Valley. The hypocentral depths of the recorded events reach 20 km, showing that the basement faults responsible for the seismicity affect at least the entire upper crust. Since the limited existing data suggest a high level of heat flow in the Lusitanian Basin, the depths reached by the microearthquakes may indicate an abnormally thick seismogenic layer. An investigation of the broad velocity structure of the lithosphere underneath the RESTE Network using the technique of teleseismic tomographic inversion suggested a correlation between Moho undulations and the inversion of areas of the Lusitanian Basin, and this may indicate that the controlling faults cut the entire crust. In order to provide a rationale for the intraplate seismicity of western Portugal, the neotectonics of Iberia are discussed, and a new kinematic model, centred on the idea of continental extrusion, is proposed. According to the model, a continental block formed by Iberia and northern Morocco is being pushed west wards by the convergence between Africa and Eurasia. The resistance offered by the oceanic parts of the plates varies across the East Azores Transform, leading to dextral shear in the Betic Range. The regional stress field induced by the continental convergence can explain the reactivation, in a simple-shear regime, of basement faults of Hercynian orientation, in particular that proposed for the Lower Tagus Valley.
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Chen, Liangjun 1972. "Seismic structure of the mantle beneath the southwestern Pacific." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/58367.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2001.Includes bibliographical references (leaves 24-28).
We jointly invert 1396 frequency-dependent travel times of turning and surface waves such as S, sS, SS, sSS, SSS, Sa, R1, and G1, together with 82 travel times of multiple ScS waves, to obtain a high-resolution, two-dimensional (2-D) vertical tomogram for the corridor between the Ryukyu subduction zone and Hawaii, which traverses the Hawaiian Swell between Midway and Oahu. The data analysis, inversion procedure, and parameterization are similar to our previous study along the Tonga-Hawaii corridor [Katzman et al., 1998], but in this study we add corrections to the measurements that account for the crustal heterogeneity and topography along the path. The model parameters include shear-speed variations throughout the mantle, perturbations to shearwave radial anisotropy in the uppermost mantle, and the topographies of the 410- and 660-km discontinuities. The model we obtained, which is well resolved in the upper mantle, exhibits high shear speeds at shallow depths and low speeds in the transition zone beneath the Pacific part of the corridor, with the lowest shear speed within a distinct upper-mantle anomaly at the depth of 200-400km near the Hawaiian Swell. Furthermore, we inverted the data from individual source arrays in New Hebrides, Solomon, and Mariana Island for two-dimensional vertical tomograms of mantle structure using the same technique as the Ryukyu-Hawaii corridor. The 2-D tomograms for these corridors were generally consistent with previous tomographic results, although they show uppermantle features that are smaller in scale and larger amplitude than published global models. We then inverted the entire data set from all corridors for a 3-D model of the southwestern Pacific upper mantle. At low wavenumbers, this regional model is consistent with large-scale features found from global tomography. However, our model displays greater lateral heterogeneity in both isotropic and anisotropic structure than the global models, especially in the 200-400 km depth range, which can be attributed to the better resolution of small-scale features by our data set. Fast and slow anomalies in isotropic shear speed are observed in the upper mantle, suggesting a complex 3-D mantle flow in the southwestern Pacific upper mantle.
by Liangjun Chen.
S.M.
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Starr, Gregory D. "NEW WORLD SALVIAS CULTIVATED IN THE SOUTHWESTERN UNITED STATES." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275411.
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