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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

Šilutės rajono užliejamų teritorijų naudojimas / Use of flooded areas in Šilutė district

Riaukaitė, Živilė 16 June 2014 (has links)
Darbas parengtas nustatant esamą situaciją užliejamose teritorijose. Tyrimo metu nustatyta, kad ūkininkauti tokiose vietose nėra lengva, nes yra taikomi apribojimai. Nustatyta, kad taikant šiuolaikines GIS technologijas būtų galima palengvinti ūkininkavimą, išskiriant vietas, kuriose palankiau ūkininkauti. Iškeltiems tyrimo uždaviniams pasiekti, buvo atlikta anketinė apklausa ir erdvinė duomenų analizė. Tyrimo tikslas – išanalizuoti Šilutės rajono užliejamų teritorijų ūkinio naudojimo tikslingumą ir numatyti perspektyvas. Tyrimo objektas – Šilutės rajono užliejamos teritorijos, išsamiau tirti trys vasaros polderiai: Uostadvario, Vorusnės, Pakalnės. Tyrimo uždaviniai: 1. Nustatyti esamą užliejamų teritorijų žemės naudojimą. 2. Aptarti duomenų, reikalingų erdvinei analizei atlikti, surinkimo ir naudojimo ypatumus. 3. Naudojant ArcGIS erdvinės duomenų analizės metodus, įvertinti žemės vertės variaciją erdvėje. 4. Įvertinti kaimo plėtros priemonių taikymą užliejamoms teritorijoms. Siekiant nustatyti Šilutės rajono užliejamų teritorijų ūkinio naudojimo tikslingumą ir perspektyvas buvo panaudoti šie metodai: anketinės apklausos, matematinės statistikos metodai, GIS duomenų erdvinė analizė. Tyrimas atliktas siekiant pademonstruoti, kaip šiuolaikinėmis GIS technologijomis galime daug tiksliau ir efektyviau įvertinti žemės vertės variaciją erdvėje bei žemės naudojimą. Polderiai išanalizuoti atliekant anketinę apklausą bei panaudojant ArcGIS 10.0 programą atlikta erdvinė duomenų... [toliau žr. visą tekstą] / The work was done by determining the current situation of flooded areas. During the research it was found that farming in such areas is not easy because of the restrictions. It was found that the application of modern GIS technology to facilitate farming, highlighting areas where favored. Raised by the study was carried out to achieve the objectives of a survey and analysis of spatial data. The goal of research is to analyze farm usage expediency and perspectives of flooded areas in Šilutės district. The object of survey is territories of flooded areas in Šilutės district, three summer polders were analyzed more comprehensively: Uostadvaris, Vorusnė, Pakalnė. Objectives of the survey: 1. To set the current land use of flooded areas. 2. To discuss the data necessary to perform spatial analysis, collection and usage. 3. To evaluate the variation of the value of land space using the ArcGIS Spatial data analysis methods. 4. Summarize applications measures of rural developments for flooded areas. The following methods: logical thinking, statistical clustering, comparison and analysis of GIS data were used to identify farm usage expediency and perspectives of flooded areas in Šilutės district. The research was completed to demonstrate how modern GIS technology can more accurately and efficiently assess the value of the land distribution and usage. Polders were analyzed via the questionnaire survey, also by use of ArcGIS 10.0 program accomplished a spatial analysis of the data... [to full text]
202

Spatial Analysis of Teen Births in North Central Texas

Donkor, Faustina Fosua 12 1900 (has links)
The United States has the highest teen birth rate among western industrialized countries and the highest levels of pregnancy among adolescents (Alan Guttmacher Institute, 1994). While the rate of teen births is high throughout the country, considerable variations exist between and within regions. Texas is one of the 5 leading states with the highest teen birth rates to mothers less than 18 years of age. This research provides a detailed analysis of births to mothers aged between 10 and 19 years in North Central Texas counties. Due to the modifiable area unit problem and to provide a finer geographical scale of analysis, teen births in Dallas County zip codes were examined as a special case study. Statistical and Geographic Information System (GIS) analysis reveal that race/ethnicity, education and income are significant factors in teen births in the region. Single parent households and receipt of public assistance were not statistically significant. Suggestions for reducing vulnerability to teen births are presented.
203

Separated by gender? A contribution to the debate on Roman Imperial Period burial grounds in northern Germany

Jonsson, Rebecka January 2016 (has links)
This study concerns 28 Roman Iron Age Germanic burial grounds located in proximity to the river Elbe (dt. "Elbegermanen"). Situated in the northern German states Brandenburg, Hamburg, Lower Saxony, Mecklenburg-Vorpommern, Saxony-Anhalt, Schleswig-Holstein and dated 0-300 AD (Earlier Roman Imperial Period); the sites primarily consist of urn burials and have been interpreted as separated by gender. Although a debated issue in German archaeology, critical questions derived from theoretical problematization have usually been omitted from the discourse. This study aims to discuss gender theory to address this research gap. Geographical patterns have been explored through a spatial analysis and reconstruction of the Roman Imperial landscape. Two sites are compared in case studies and the end results connect the theoretical discussions and GIS-analysis. The results show that the combination of a large-scale regional analysis and small-scale analysis of specific sites is beneficial in order to acknowledge the varieties and move beyond the interpretations that dominate the prevalent discourse.
204

Spatial analysis of marine mammal distributions and densities for supporting coastal conservation and marine planning in British Columbia, Canada

Harvey, Gillian Kohl Allyson 23 December 2016 (has links)
Human impacts on ocean ecosystems are driving declines in marine biodiversity, including marine mammals. Comprehensive spatial data are vital for making informed management decisions that may aid species recovery and facilitate the sustainable use of ocean ecosystems. However, marine mammal studies are often data limited, thereby restricting possible research questions. Developing novel analytical approaches and incorporating unconventional datasets can expand the scope of analysis by increasing the information content of existing data sources. The goal of our research is to support conservation and management of marine mammals in British Columbia (BC), Canada, through the application of advanced spatial statistical methodology to characterize spatial distribution and density patterns and provide assessments of data uncertainty. Our first objective is to generate statistical models to map spatially continuous predictions of marine mammal distributions and densities within BC’s north coast and apply methodology from spatial statistics to identify hotspots of elevated use. We use species observations collected from systematic line transect surveys previously adjusted to generate estimates of density per nautical mile of transect. We predict the distribution and density patterns of nine marine mammal species by employing a species-habitat model to relate species densities to environmental covariates using a generalized additive model. We use spatial statistical hotspot analysis (Getis-Ord Gi*statistic) and an aspatial threshold approach to identify hotspots of high density. Our analysis reveals that hotspots selected using a top percentage threshold produced smaller and more conservative hotspots than those generated using the Gi*statistic. The Gi*statistic demonstrates a robust and objective technique for quantifying spatial hotspots and offers an alternative method to the commonly applied aspatial threshold measure. We find that maps show agreement with prior research and hotspots align with ecologically important areas previously identified by expert opinion. Our second objective is to apply map comparison techniques to compare cetacean density maps from disparate data collection methods (systematic surveys and citizen science) to evaluate the information content of each map product and quantify similarities and differences. Discrepancies are quantified by performing image differencing techniques on the rank order values of each map surface. We subsequently use the Gi*statistic to isolate regions where extreme differences occur. To assess similarities, a Gi*statistic is applied to both maps to locate spatially explicit areas of high cetacean density. Where clusters of high density values in both maps overlap we infer higher confidence that the datasets are representing a true ecological signal, while areas of difference we recommend as targeted locations for future sampling effort. We contextualize map similarities and differences using a dataset of human activity in the form of cumulative human effect scores. Overall, our analytical approach integrates novel spatial datasets from systematic surveys, citizen science, and remote sensing to provide updated information on cetacean distributions in BC. Our study generates geographic data products that fill knowledge gaps and results provide baseline information valuable for future decision-making. The methodology applied in this study can be generalized across species and locations to support spatial planning and conservation prioritization in both marine and terrestrial contexts. / Graduate / 2017-11-13
205

Persistent Local-Area Chlamydia and Gonorrhea Clusters and Associated Community Characteristics in the Southeastern United States

Scott, Lia CB 09 January 2015 (has links)
Background: The sexually transmitted infections (STIs), chlamydia and gonorrhea, disproportionately affect racial and ethnic minorities. Community attributes like poverty and prevalence of STIs, along with residential segregation and its impact on composition of sexual networks contribute to these disparate rates. The Southeast had the highest rates of chlamydial and gonorrheal infection among the four regions of the United States. Because relationships between race and place can confound national statistics, it is important to examine whether racial disparities within the region are associated with higher rates of infection. Purpose: The study aims to evaluate local geospatial clustering of gonorrhea and chlamydia rates in the Southeast, and their persistence during 2000-2005 and any associations with residential segregation, income inequality, unemployment and uninsured rates, and race. Methods: Using the Local Indicators of Spatial Association tests of spatial clustering, cluster maps were created for each STI outcome and year. Independent sample t-tests were then used to examine the difference in means of each community level variable across counties composing the high-rate clusters and all other counties in the region. Results: Over 60% of counties composing high-rate clusters persisted as high rate clusters over time, and were significantly associated with higher levels of community disadvantage than all other counties (p < 0.01). Overall gonorrhea rates decreased from 2000 to 2005 and chlamydia rates increased, while their associations with community disadvantage remained persistently strong over time. Conclusions: Counties with higher rates of chlamydia and gonorrhea persist over time and experience persistently higher levels of residential segregation and income inequality, as well as higher unemployment and uninsured rates, and higher proportions of blacks in the population. The social environment and segregated sexual networks may play important roles in the persistently high rates of chlamydia and gonorrhea observed for certain regions within the Southeast. Continued surveillance of reportable STIs and their probable predictors is needed in order to better understand the persistent disparities in STI rates across counties in the Southeast.
206

Tracking Dabbing Using Search Query Surveillance: A Case Study in the United States

Zhang, Zhu, Zheng, Xiaolong, Zeng, Daniel Dajun, Leischow, Scott J 16 September 2016 (has links)
Background: Dabbing is an emerging method of marijuana ingestion. However, little is known about dabbing owing to limited surveillance data on dabbing. Objective: The aim of the study was to analyze Google search data to assess the scope and breadth of information seeking on dabbing. Methods: Google Trends data about dabbing and related topics (eg, electronic nicotine delivery system [ENDS], also known as e-cigarettes) in the United States between January 2004 and December 2015 were collected by using relevant search terms such as "dab rig." The correlation between dabbing (including topics: dab and hash oil) and ENDS (including topics: vaping and e-cigarette) searches, the regional distribution of dabbing searches, and the impact of cannabis legalization policies on geographical location in 2015 were analyzed. Results: Searches regarding dabbing increased in the United States over time, with 1,526,280 estimated searches during 2015. Searches for dab and vaping have very similar temporal patterns, where the Pearson correlation coefficient (PCC) is .992 (P<.001). Similar phenomena were also obtained in searches for hash oil and e-cigarette, in which the corresponding PCC is .931 (P<.001). Dabbing information was searched more in some western states than other regions. The average dabbing searches were significantly higher in the states with medical and recreational marijuana legalization than in the states with only medical marijuana legalization (P=.02) or the states without medical and recreational marijuana legalization (P=.01). Conclusions: Public interest in dabbing is increasing in the United States. There are close associations between dabbing and ENDS searches. The findings suggest greater popularity of dabs in the states that legalized medical and recreational marijuana use. This study proposes a novel and timely way of cannabis surveillance, and these findings can help enhance the understanding of the popularity of dabbing and provide insights for future research and informed policy making on dabbing.
207

Geographical Information Systems (GIS) Applied to Urban Nutrient Management: Data Scarce Case Studies from Belize and Florida

Haberstroh, Charlotte Juliane 16 March 2017 (has links)
Nutrient inputs into the environment greatly impact urban ecosystems. Appropriate management strategies are needed to limit eutrophication of surface water bodies and contamination of groundwater. In many existing urban environments, retrofits or complete upgrades are needed for stormwater and/or wastewater infrastructure to manage nutrients. However, sustainable urban nutrient management requires comprehensive baseline data that is often not available. A Framework for Urban Nutrient (FUN) Management for Geographic Information Systems (GIS) was developed to specifically address those areas with limited data access. Using spatial analysis in GIS, it links water quality, land use, and socio-demographics, thereby reducing data collection and field-based surveying efforts. It also presents preliminary results in a visually accessible format, potentially improving how data is shared and discussed amongst diverse stakeholders. This framework was applied to two case studies, one in Orange County Florida and one in Placencia, Belize. A stormwater pond index (SPI) was developed to evaluate 961 residential wet ponds in Orange County, Florida where data was available for land use and socio-demographic parameters, but limited for water quality. The SPI consisted of three categories (recreation, aesthetics, education) with a total of 13 indicators and provided a way to score the cultural and ecosystem services of 41 ponds based on available data. Using only three indicators (presence of a fence, Dissolved Oxygen (DO) < 4 mg/l, and water depth < 3 ft), 371 out of 961 stormwater ponds were assessed. Additional criteria based on socio-demographic information (distance to a school, population density, median household income under $50,000, percentage of population below the poverty line, and distance to parks) identified seven wet ponds as optimum for potential intervention to benefit residents and urban nutrient management purposes. For the second case study, a water quality analysis and impact assessment was performed for the Placencia peninsula and lagoon in Belize. This study had access to water quality data, but limited land use data and very limited socio-demographic data. Since May 2014, water quality samples have been taken from 56 locations and analyzed monthly. For this study, Dissolved Oxygen (DO), Nitrate (NO3--N), Ammonia (NH3), Chemical Oxygen Demand (COD), and 5-Day Biochemical Oxygen Demand (BOD5), Escherichia coli (E. coli), and Enterococci were selected to assess spatial and temporal variation of water quality in the groundwater on the peninsula as well as the surface water in lagoon, estuaries and along the coast. A spline interpolation of DO, Nitrate, BOD5, and COD for June 2016 indicated the concentration distribution of those parameters and areas of special concern. A spatial analysis was conducted that showed that Nitrate and Enterococci exceeded the effluent limits of Belize very frequently in the complete study area while the other parameters contributed to the identification of key areas of concern. As a high variability of concentrations over time was observed, a temporal analysis was conducted identifying a link between the water quality data and two temporal impact factors, rainfall and tourism. The two case studies showed the broad and flexible application of the FUN management for GIS and the great advantages the use of GIS offers to reduce costs and resources use.
208

Souvislosti rozmístění socioekonomických charakteristik obyvatelstva a hospodářství ve vztahu k železniční síti v Československu v letech 1921 a 1930 / Connection between distribution of socio-economic characteristics of population and economy in relation to railway network in Czechoslovakia in 1921 and 1930

Marek, Martin Václav January 2015 (has links)
Connection between distribution of socio-economic characteristics of population and economy in relation to railway network in Czechoslovakia in 1921 and 1930 Abstract Transport is closely related with social and economic processes in space and they affect each other. History of transport, and economy and history of the population are themes quite well covered. Attempts to synthetically cover history of transport and society and its activities in the space have not been numerous, if any they only referred to certain examples, although the transport, especially rail, is mentioned as an important factor of development. The diploma thesis analyzes statistical dependece of selected demographic and socioeconomic characteristics of national censuses in 1921 and 1930 and economic characteristics and agriculural units in 1930 on rail infrastructure in the Czechoslovak Republic. The key statistical data are selected census results (eg. age of population, literacy and inhabitans in the sector of the national economy), results of census of economic and agricultural units (for example units equipment) at the level of administrative units in Czechoslovakia. Spatial data (maps) are an important source, too. These allow statistical and visualization operations in the GIS. They had to be digitized in order to create map...
209

Analyse cartographique de la structure des paysages de vallées : évaluation de la dynamique des paysages de vallées du bassin versant de la Maine à partir de la télédétection et de SIG / Cartographic analysis of the structure of landscapes of valleys : evaluation of landscape dynamics in valleys of Maine Watershed using remote sensing and GIS

Alhaskeer, Ziad 21 December 2012 (has links)
Les vallées du bassin versant de la Maine forment des paysages diversifiés soumis à des enjeux multiples(étalement urbain, activités agricoles, boisements). Les interactions entre l’eau et les activités humainesprésentent une certaine variabilité. Pour rendre compte des caractéristiques des vallées, de leurs diversités et deleurs singularités, la recherche est fondée sur les descripteurs objectifs (matériels) en utilisant d’une approche multiscalaire et reproductible. Une typologie des types de vallées est réalisée en s’appuyant sur une approche morphologique (MNT/analyse spatiale) pour caractériser les morphologies de vallées et une approche des modes d’occupation du sol (traitement d’images LANDSAT ETM+7) pour renseigner les types de couvertures du sol.23 types des paysages de vallées sont identifiés. La typologie met surtout en évidence la diversité de paysages devallée, pourtant souvent négligée par les approches classiques. La confrontation des résultats de cette typologieavec les atlas des paysages valide les types de vallées. Un suivi des changements dans les vallées du bassinversant de la Maine est mesuré, à partir d’images LANDSAT TM 1984 et ETM 2003, en utilisant les outilsgéomatiques (télédétection, SIG et techniques statistiques). Les méthodes et les procédures adoptées dans cetterecherche sont la cartographie de l’occupation du sol, l’obtention d’indicateurs et la cartographie deschangements. Les vallées intermédiaires sont les vallées les plus soumises aux changements, alors qu’aucontraire, les vallées jugées remarquables (gorges, vallées très encaissées et les basses vallées) sont les valléesayant le moins évolué. La détection des changements par type de vallées met en avant l’intérêt de combinaisond’approches morphologiques et d’approches d’occupation du sol, ce qui permet de montrer l’influence de naturedes reliefs à l’évolution d’occupation du sol. La confrontation des types de vallées avec les politiques paysagèrespermet de mettre en évidence le rôle des acteurs dans la gestion de ces espaces. Ainsi, le travail avec d’autrestypes des données, d’autres zones et avec une échelle plus fine permet de valider les résultats tirés des vallées dubassin versant de la Maine. / The valleys of Maine Basin contain diverse landscapes subjected to multiple issues (urban sprawl, agriculturalactivities, and afforestation). The interactions between water and human activities have some variability. In orderto reveal the characteristics of the valleys, their diversity and their singularities, the research is based on thedescriptors objectives (hardware) using a multi-scale approach and reproducible. A typology of types of valleysis performed based on a morphological approach (MNT / spatial analysis) to characterize morphological formsvalleys and approach patterns of land cover (processing of images LANDSAT ETM +7) to inform the types ofland cover. The typology particularly highlights the diverse landscapes of valleys often neglected by classicapproaches. Comparing the results of this typology with the atlas reveals the importance of landscape andvalidation of type’s valleys. Monitoring changes in the valleys of Maine Basin is measured from LANDSAT TM1984 and ETM 2003, using geometrics tools (remote sensing, GIS and geo-statistical techniques). The methodsand procedures adopted in this research were the cartographic of land cover, subtraction indicators and mappingchanges. The intermediate valleys are valleys most subject to change, but, on the contrary, remarkable valleys(gorges, valleys and very steep low valleys) are the valleys less subject to change. The change detection byvalleys types emphasizes the interest combining morphological approach and the approach of land cover andthereby shows the influence the nature of reliefs to changing land cover. The confrontation the types of valleyswith landscape policies can highlight the role of stakeholders in the management of these areas. Thus, workingwith other types of data, and other areas with a finer scale can validate the results from the valleys of MaineBasin.
210

Sand dune movement and its impact on human activities in the north western coast region of Libya : an analysis of the sediment characteristics of sand dunes, and their movement using satellite images, and the effects of encroachment on farms assessed by a questionnaire survey

Koja, Suliman Farag January 2012 (has links)
Sand movement is one of the many environmental problems facing humans in the dry and semi-dry areas of the world. This study has investigated the observed changes in sand dune coverage compared to predictions, and has also assessed the impact of sand movement on human activity in the north western coastal region of Libya. The study used three methods. The first was a statistical model proposed by Bagnold, which correlates wind shear velocity with particle size, in order to predict likely sand movement. It was found that 60% of sand grains within the study area have a diameter of less than 0.25 mm, making them liable to be moved by the wind speeds recorded, particularly from March until September, and mostly in a northerly direction. The sand in the western part of the study area had a greater predicted rate of sand transport compared with the sand in the eastern part, which was related to its origin. The second method involved the analysis of satellite images for four different years; from 1986 to 2003. The land cover in the study area was found to have changed over this time. Sand dune area cover had increased, and there were other changes particularly a decline in forest. The third method was the use of a questionnaire (the respondents being land owners), which showed that there was notable loss of crop production (by about a quarter) due to sand movement, and that land owners mostly used afforestation to help control the sand movement in the region. The observed sand movement did not match the predictions based solely on sand grain size and wind speed, and climatic analyses showed no convincing trends which could explain increased sand movement except perhaps an increase in wind gusts. The thesis concludes that the overriding determinant in greater sand movement over the period studied was the loss of forest from the area due to human impacts, which farmers are having to compensate for by planting trees locally to reduce sand movement.

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