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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.
31

Determining Florida Landfill Odor Buffer Distances Using Aermod

Figueroa, Veronica 01 January 2008 (has links)
As U.S. landfills continue to grow in size, concerns about odorous gas emissions from landfills are increasing. For states that are expanding in population, such as Florida, odors from landfills are a major concern because new housing developments, needed to accommodate the rapid population growth, are creeping closer and closer to the existing landfills. As homes get closer to landfills, odor complaints are likely to become more frequent, causing landfill managers increased problems with public interactions. Odor buffer zones around landfills need to be established to give municipalities tools to help prevent the building of future homes too close to landfills. Using the latest air dispersion model, AERMOD, research predicted downwind odor concentrations from a Central Florida landfill. Accurate estimates of methane emissions throughout a Central Florida landfill were determined using a new technique developed as part of this research that uses hundreds of ambient air VOC measurements taken within a landfill, as receptors. Hundreds of point sources were placed on the landfill, and the standard Gaussian dispersion equations were solved by matrix inversion methods. The methane emission rates were then used as surrogates for odor emissions to predict downwind odor concentrations via AERMOD. By determining a critical zone around a landfill with regards to odor, stakeholders will be able to meet regulatory issues and assist their communities. Other beneficial uses from this research include: determination of existing gas collection system efficiencies, calculation of fugitive greenhouse gas emissions from municipal solid waste (MSW) landfills, and improved landfill gas management.
32

Régime des pluies et déforestation en Amazonie Méridionale / Precipitation patterns in Southern Amazonia and its relation to deforestation / O regime de chuvas na Amazônia Meridional e sua relação com o desmatamento

Debortoli, Nathan Dos Santos 05 July 2013 (has links)
207 postes pluviométriques de l’Agence brésilienne sur l’eau (ANA) dans le sud de l'Amazonie et au nord du Cerrado sont analysés, tout en utilisant des tests non-paramétriques de Pettitt qui identifie les ruptures dans les séries chronologiques de pluviométrie, le test de Mann-Kendall qui détecte des tendances annuelles et saisonnières des indices pluviométriques, ainsi qu’un modèle de régression linéaire qui identifie les tendances subtiles de croissance ou décroissance dans les précipitations. Le test de Pettitt a indiqué 16% des ruptures dans les séries chronologiques des précipitations, et le test mensuel/saisonnière de Mann-Kendall a mis en évidence que 41% des postes ont des tendances négatives, principalement dans les saisons de transition (début et fin de la saison de pluie). Le modèle de régression linéaire a montré que 63% des données ont présenté des tendances négatives. Et en fine échelle les données temporelles nous ont permis d’identifier les dates de début et fin de la saison des pluies. Les résultats suggèrent qu'il existe de forts contrastes entre l'Amazonie et le Cerrado. Cette analyse chronologique a également indiqué que durant la période couverte par l’étude il y a eu un retard dans le début de la saison des pluies pour 84% des postes pluviométriques, et pour la fin un décalage prématuré de 76%, et pour son ampleur une diminution en 88%. L’analyse de krigeage exponentielle ordinaire des postes pluviométriques dans les zones déboisées a également révélé qu’il y a d’importantes chances que la déforestation soit un adjuvant à l'affaiblissement de la saison des pluies, en particulier dans les zones fortement déboisées de l’État de Mato Grosso et les régions au nord de l’État de Rondônia. Dans ce travail, des séries chronologiques des précipitations sont mises en corrélation avec des données d’occupation du sol, acquises par des images satellites Landsat 5, à partir d'une perspective temporelle. Cette analyse des zones tampons (1-50km) est divisée par 3 périodes de couverture forestière (avant 1997, parmi 1997-2010 et 2010) a indiqué que sur le plan local, au niveau des précipitations, il n’existe pas de corrélation. Pourtant, la méthodologie des zones tampons a suggéré que dans les grandes zones forestières, elle peut éventuellement s’appliquer. Malgré que les données climatiques ne montrent pas decorrélation significative avec les données de la couverture forestière, les analyses de Pettit, Mann-Kendall, la régression linéaire et l'identification de la saison des pluies rejoignent des découvertes récentes sur les modèles de circulation de large-échelle / 207 Rain Gauges (RG) of the Brazilian National Agency for Water (ANA) were analyzed using statistical non-parametrical tests. The Pettitt’s test identified ruptures in the chronological rainfall series, while the Mann-Kendall’s test detected annual and seasonal tendencies in rainfall indexes and a linear regression analysis identified slight gain or loss in precipitation. Pettitt’s test indicated 16% of ruptures in the chronological rainfall series at the same time as Mann-Kendall’s monthly test put in evidence 41% of the RG having negative trends in transition seasons (onset and offset of the rainy season). Lastly the linear regression analysis showed 63% of data having negative trends. Additionally the dates of onset and offset of the rainy season were identified and its results submitted to Mann-Kendall’s and the linear regression approach. The data suggests strong contrasts between the Southern Amazon and the Northern Cerrado showing a delay on the onset of the rainy season for 84% of the RG, a premature offset for 76% and a reduction in the rainfall seasonal extend for 88%. An exponential ordinary kriging analysis of RG in deforested areas also revealed major chances of deforestation areas working as an adjuvant in the weakening of the rainy season- especially in highly deforested areas of the Mato Grosso State and the northern Rondônia. Aiming to build a tool to detect interactions between land surface and rainfall patterns the207 RG were correlated through a buffer zones analysis with land use data acquired from satellite LANDSAT 5. The time frame previously selected was divided into three periods of forest cover (before 1997, between 1997-2010 and acumulated for 2010). The cross-related buffer zones analysis (1-50km) indicated at local level that precipitation patterns are not well correlated to forest cover. Yet the buffer zones methodology suggested that as larger the forest areas are, larger are the probabilities of those influencing precipitation at regional scale, contrary to forest fragments in local level. Despite the climatic data in the buffer analyzes do not reveal significant correlation to forest cover, the statistic Pettit and Mann-Kendall tests, the linear regression analyzes and the identification of the rainy season, confirmed a fine linkage with recent findings which focus large-scale circulation models including forest cover as a variable / Este estudo analisou 207 estações pluviométricas da Agência Nacional das Águas (ANA) no Sul da Amazônia e no Cerrado no período de 1970-2010, utiizando-se dos testes estatísticos não-paramétricos de Pettitt que identifica rupturas nas séries cronológicas pluviométricas, o teste de Mann-Kendall que detecta tendências anuais e sazonais dos índices pluviométricos, e uma análise de regressão linear que identifica tendências sutis de acréscimo ou decréscimo nas precipitações. O teste de Pettitt indicou um total de 16% de rupturas nas séries cronológicas de chuva enquanto que o teste sazonal/mensal de Mann-Kendall coloca em evidência que 41% das estações apresentam tendências negativas principalmente nas estações de transição (início e fim da estação chuvosa). Já a análise de regressão linear indicou que 63% dos dados apresentam tendências negativas nas precipitações. Como complemento também foram identificadas as datas do início e fim da estação chuvosa. Esta se deu por meio da adaptação de método estatístico atrelado às análise de tendências de Mann-Kendall e de regressão linear. Os resultados sugerem fortes contrastes entre o Sul Amazônico e o Cerrado. Esta análise cronológica do período chuvoso indicou o atraso significativo no início da estação chuvosa para 84% das estações, e um fim prematuro em 76%, além da redução do período em 88% dos casos. Por fim, foi desenvolvido,examinado e verificado a correlação de dados climáticos e cobertura do solo através da análise climática oriunda da regressão linear, e da classificação do uso da terra adquiridos do satélite LANDSAT 5 a partir de uma perspectiva temporal. A correlação dos dados delimitados por zonas tampão de 1-50km e divididos em 3 períodos cronológicos anteriores a 1997, entre 1997-2010 e o acumulado de 2010 contemplam o total de floresta. As análises indicam que os padrões de precipitação local não são correlacionados diretamente a cobertura florestal. No entanto, a metodologia de zonas tampão sugere que quanto maiores as áreas de floresta, maiores são as probabilidades destas influenciarem as precipitações, ao contrário de pequenos fragmentos florestais como indicado nos resultados das correlações até 50km. Apesar dos dados climáticos não mostrarem correlação significativa com os dados da cobertura florestal, as análises dos testes de Pettit, Mann-Kendall, regressão linear e de identificação do período chuvoso vão em direção de descobertas recentes com foco nos modelos de circulação em larga-escala, que incluem a cobertura florestal como variável
33

Management Options in the Buffer Zones of Protected Areas in the South Caucasus – Socio-economic and institutional Background and economic Preferences

Kalatas, Talin 23 July 2015 (has links)
No description available.
34

The effect of land use on the species composition of amphibians in North Eastern KwaZulu-Natal.

Russell, Charlene. January 2010 (has links)
Global declines in amphibian species have directed research towards investigating why this is happening. One of the major causes of these declines is the fragmentation and loss of habitat. This study examined the effect of land use on the species composition of frogs within North Eastern KwaZulu-Natal, and the use of buffer zones to facilitate the protection of these species. Three land use types were investigated: sugar cane (Saccharum officinarum), gum (Eucalyptus sp.) plantations and conservation areas. The average number of frog species differed between areas: conservation 13.2 ± 6.6; plantations 3.8 ± 1.3; and sugar cane 2.8 ± 1.4. Sugar and gum plantation were found to be lacking the wetland and grassland/woodland habitats. In addition to this, the frog species that were not present on these land use types were those that are totally dependent on water as well as those that are not dependent on a water source. Two species were highlighted as possible indicator species of land use: Amietophrynus gutturalis and Hyperolius marmoratus. To mitigate the effect of these land use types, the use of buffer zones was explored in a desktop study. A range of buffer zones were applied to wetlands in a sample study area, using a range of distances including the distances of 290 m and 159 m recommended by Semlitsch and Bodie (2003), and the recommended distances for wetlands in South Africa of 10-20 m. The application of a 290 m and 159 m buffer zone on a conglomerate of wetlands connected by a 100m buffer was the most feasible as it incorporated a percentage of the total study (6.4% and 4.3%) area similar to the percentage occupied by the recommended 20m buffer zone (5.5%) around all wetlands, and still incorporated the range under protection put forward by Semlitsch and Bodie (2003). Management implications of these findings are discussed. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.
35

Deciduous trees in the riparian zone: influence on the composition and diversity of macroinvertebrate communities in boreal streams / Lövträd i strandzonen: påverkan av sammansättningen och mångfalden av makroinvertebraternas samhällen i boreala bäckar

Källberg, Sara January 2024 (has links)
Litter input from riparian tree cover brings organic matter and nutrients to streams and is a driving factor of stream communities and food webs. In particular, changes in the composition and cover of riparian forests could affect stream light conditions as well as the amount and quality of terrestrial litter inputs. In northern Swedish landscapes, riparian zones of headwater streams are dominated by coniferous species, and current forest management guidelines suggest that we should prioritize greater deciduous cover in streamside forests to promote the ecological condition of streams. In this study, I investigated how deciduous forest cover in riparian zones may influence the composition and diversity of macroinvertebrate communities in boreal headwater streams. Macroinvertebrates from samples collected at eight streams ranging from spruce- to birch-dominated riparian zones were sorted, identified to family, and used to generate metrics describing taxonomic richness, community composition, and functional feeding groups. Correlation analysis showed no statistical relationship between riparian deciduousness and macroinvertebrate richness across sites, although evenness decreased with deciduous cover. Indeed, variation in some community metrics (e.g., the % herbivores) were more closely linked to water chemistry (e.g., pH) than to local riparian composition. While this study is limited by the low statistical power and lack of seasonal resolution, results suggest that other catchment properties may influence how boreal stream communities respond to local riparian cover.
36

Keying forest stream protection to aquatic ecosystem values in multi-ownership watersheds

Pickard, Brian R. 15 March 2013 (has links)
Forested lands of western Oregon provide aquatic habitat for many fish and riparian dependent species, including a wide variety of salmon species. Current policies set riparian protections using fixed buffers on streams for federal and private lands based on stream type or size. These buffers can create a series of disjointed riparian protections, as federal lands require buffers that are much larger than private lands. In addition, the fixed buffer approach is neither flexible nor tailored to aquatic ecosystem values. This thesis presents a framework for comprehensively assessing stream networks using site specific watershed features and then suggests riparian conservation strategies that key stream and riparian protection to aquatic ecosystem values. Seven study watersheds were used in this analysis, totaling over 2.5 million acres of forested lands in western Oregon. Employing a set of geospatial tools, called NetMap, streams in each watershed were classified into higher and lower priorities using criteria of intrinsic potential, erosion/debris flow susceptibility, and thermal loading potential. Results demonstrated the inherent variability within and among watersheds based on the geomorphic and ecological processes determined important for selected salmon species. Within each watershed, both federal and non-federal lands had many miles of higher priority fish-bearing and non-fish bearing streams, suggesting the need for comprehensive, holistic watershed conservation strategies. Based on the partitioning of streams into higher and lower priorities, an alternative riparian conservation strategy was then modeled for federal lands that allocate protection on the basis of the ecological context of a stream segment’s potential and particular location while still meeting federal aquatic conservation goals and objectives. Possible increases to the land base for long-term timber production were then identified if this strategy were applied to federal Matrix lands. Results demonstrated that 8-30 percent of the current riparian buffers could be reallocated to the land base for long-term timber production. An additional 26-45 percent of current buffers could be managed simultaneously for both timber production and aquatic ecosystem goals. Results also provided a framework for targeting of conservation and restoration efforts towards higher priority streams within each watershed. As many of the most ecologically important streams were located on non-federal lands, riparian conservation policies focused on streams classified as higher priority on those lands may be needed to protect aquatic species and their environments. / Graduation date: 2013
37

Modeling the impact of buffer strips on phosphorus concentration in Buck Creek Watershed, Indiana : a GIS approach

Gopinath, Raju 29 June 2011 (has links)
This study has attempted to model and quantify the impacts of Beneficial Management Practices (BMP) like buffer strips on the phosphorus concentration and loading in the Buck Creek Watershed of Central Indiana. The GIS based modeling was done using the Soil and Water Assessment Tool (SWAT) developed by the U.S. Department of Agriculture-Agricultural Research Services (USDA-ARS). The results from the EPA funded two year (2002-2004) Upper White River Watershed Project (UWRWP) for the Buck Creek Watershed were used as the measured base data for the modeling evaluation. These measured data were compared against the data generated out of the model simulation based on two different scenarios which took into consideration the combinations of land use, agricultural management practices, point source pollutions and BMPs. Scenario-1 simulated all the aspects of land use intensity, moderate agricultural management practices and moderate point source pollutions taking place in the Buck Creek watershed. While running the model in scenario-1, there was a noticeable increase in the phosphorus loading to the sub-watersheds ranging from 10% in the lowland sub-watershed of BC-4 to 39% in the highland sub-watershed of BC-7. In scenario-2, BMPs were implemented in the model which added 100 acres of vegetated buffer strips uniformly in all sub-watersheds and 3 acres of grassed buffers along the streams except BC-3. On re-running the model in scenario-2, there was a drastic decline in the phosphorus loading to the stream. It has been noted that there was at least 15% reduction in the loading of phosphorus to the stream where buffer strips were implemented. The present GIS modeling study helped to quantify the changes in the loading of sediments and nutrients which are induced by any parametric changes in the watershed including soil, slope, land use, agricultural management practices and BMPs. / Department of Geography
38

"Вишекритеријумски приступ организацији функционалних заштитних зона природних добара у циљу смањења антропогених утицаја" / "Višekriterijumski pristup organizaciji funkcionalnih zaštitnih zona prirodnih dobara u cilju smanjenja antropogenih uticaja" / "Multi Criteria Approach to Organising Functional Protective Zones of Natural Resources Aiming to Reduce Anthropogenic Impact"

Kicošev Vesna 21 April 2016 (has links)
<p>Докторска дисертација &bdquo;Вишекритеријумски приступ организацији функционалних заштитних зона природних добара у циљу смањења антропогених утицаја&ldquo; урађена је као резултат потребе за јачањем улоге заштитне зоне у очувању биодиверзитета, функционалности екосистема и квалитета екосистемских услуга, уз одрживо коришћење простора и ресурса. Анализа могућности формирања функционалних заштитних зона и утврђивање кључних критеријума за успостављање ових просторних целина, вршени су за подручја која припадају Панонском биогеографском региону.<br />Услед изузетне комплексности ове проблематике, чије решавање захтева мултидисциплинаран приступ уз комбинацију природних и друштвених наука, примењен је већи број метода истраживања ради упоређивања резултата и доношења закључака којима би се најприближније одговорило еколошким, социо-економским и другим потребама одрживог развоја. Анализа података извршена је применом модела и коришћењем математички изражених поступака, који су добијени адаптацијом постојећих модела и поступака, са мањим или већим изменама и одређеним новинама. Највеће измене извршене су у оквиру поступака везаним за одређивање статуса угрожене животне средине и приоритета за санацију и ремедијацију који су, у оригиналном облику, наведену легислативу из области заштите животне средине чинили тешко применљивом у пракси. Модел Леополдових матрица у великој мери олакшава спровођење поступка процене утицаја на животну средину, а за потребе практичне примене ове дисертације прилагођен је захтевима заштите природе. Значајан допринос докторске дисертације организацији функционалних заштитних зона дају једначине које су постављене у циљу побољшања процене потенцијалног и укупног релативног губитка станишта, насталог под утицајем антропогених фактора.</p> / <p>Doktorska disertacija &bdquo;Višekriterijumski pristup organizaciji funkcionalnih zaštitnih zona prirodnih dobara u cilju smanjenja antropogenih uticaja&ldquo; urađena je kao rezultat potrebe za jačanjem uloge zaštitne zone u očuvanju biodiverziteta, funkcionalnosti ekosistema i kvaliteta ekosistemskih usluga, uz održivo korišćenje prostora i resursa. Analiza mogućnosti formiranja funkcionalnih zaštitnih zona i utvrđivanje ključnih kriterijuma za uspostavljanje ovih prostornih celina, vršeni su za područja koja pripadaju Panonskom biogeografskom regionu.<br />Usled izuzetne kompleksnosti ove problematike, čije rešavanje zahteva multidisciplinaran pristup uz kombinaciju prirodnih i društvenih nauka, primenjen je veći broj metoda istraživanja radi upoređivanja rezultata i donošenja zaključaka kojima bi se najpribližnije odgovorilo ekološkim, socio-ekonomskim i drugim potrebama održivog razvoja. Analiza podataka izvršena je primenom modela i korišćenjem matematički izraženih postupaka, koji su dobijeni adaptacijom postojećih modela i postupaka, sa manjim ili većim izmenama i određenim novinama. Najveće izmene izvršene su u okviru postupaka vezanim za određivanje statusa ugrožene životne sredine i prioriteta za sanaciju i remedijaciju koji su, u originalnom obliku, navedenu legislativu iz oblasti zaštite životne sredine činili teško primenljivom u praksi. Model Leopoldovih matrica u velikoj meri olakšava sprovođenje postupka procene uticaja na životnu sredinu, a za potrebe praktične primene ove disertacije prilagođen je zahtevima zaštite prirode. Značajan doprinos doktorske disertacije organizaciji funkcionalnih zaštitnih zona daju jednačine koje su postavljene u cilju poboljšanja procene potencijalnog i ukupnog relativnog gubitka staništa, nastalog pod uticajem antropogenih faktora.</p> / <p>A Doctoral thesis entitled &ldquo;Multicriteria Approach to Organising Functional Protective Zones of Natural Resources Aiming to Reduce Anthropogenic Impact&rdquo; was developed as a result of the necessity for strengthening the role of the protective zone in the preservation of biodiversity, ecosystem functionality and the quality of ecosystem services, while utilising the space and resources in a sustainable manner. The analysis of the possibility of establishing functional protective zones and identificaton of key criteria for establishing these spatial entireties were carried out for areas belonging to the Pannonian bio-geographical region. The area of central Banat in the vicinity of protected areas &ndash; &ldquo;Slano Kopovo&rdquo; Special Nature Reserve (SNR), &ldquo;Rusanda&rdquo; Nature Park and &ldquo;Okanj Bara&rdquo; Special Nature Reserve was chosen for this research.<br />Due to extreme complexity of this subject matter, whose solving requires multi-disciplinary approach combining science and humanities, a few research methods were applied in order to compare results and make conclusions which would most appropriately meet the ecological, socio-economical and other needs of sustainable development. The data analysis was conducted by applying the model and using mathematically expressed procedures obtained through the adaption of existing models and procedures, with minor or major modifications and certain innovation. The greatest changes were made within the procedures related to the determination of a status of endangered environment and priorities for recovery and remediation which, in their original form, made even the mentioned legislation in the field of environmental protection difficult to apply in practice.<br />The model of Leopold matrix greatly facilitates the implementation of the procedure of assessment of impacts on the environment and in order to use this Doctoral thesis appropriately, it is adapted to the requirements of the nature protection. A significant contribution of the Doctoral thesis to the organisation of functional protective zones is provided by equations developed in order to improve the assessment of the potential and total relative loss of habitats which occurred as a result of pollution.</p>
39

An assessment of the contribution of agricultural non-point source pollution on the water quality of the Vaal River within the Grootdraai Dam catchment

Ncube, Scott 26 January 2015 (has links)
This study assesses the contribution of agricultural non-point source pollution, to poor water quality of the Vaal River within the Grootdraai dam catchment area. The study evaluates agricultural pollutants affecting the quality of water within the study area. The impact of agricultural non-point source pollution on the water quality of the Vaal River was evaluated by establishing a correlation between the quantity of polluted runoff reaching the River and the quantity of measured nitrates and phosphates in its waters. A questionnaire using random sampling was used to capture data from 15 commercial farmers 35 local residents and the Department of Water Affairs management. The results of the study show that agricultural nutrients are heavily impacting and compromising the water quality of the Grootdraai Dam. The mean concentrations of Nitrogen and Phosphorus were found to be well above the water quality guidelines there by promoting eutrophication. / Environmental Sciences / M. Sc. (Environmental Management)
40

An assessment of the contribution of agricultural non-point source pollution on the water quality of the Vaal River within the Grootdraai Dam catchment

Ncube, Scott 26 January 2015 (has links)
This study assesses the contribution of agricultural non-point source pollution, to poor water quality of the Vaal River within the Grootdraai dam catchment area. The study evaluates agricultural pollutants affecting the quality of water within the study area. The impact of agricultural non-point source pollution on the water quality of the Vaal River was evaluated by establishing a correlation between the quantity of polluted runoff reaching the River and the quantity of measured nitrates and phosphates in its waters. A questionnaire using random sampling was used to capture data from 15 commercial farmers 35 local residents and the Department of Water Affairs management. The results of the study show that agricultural nutrients are heavily impacting and compromising the water quality of the Grootdraai Dam. The mean concentrations of Nitrogen and Phosphorus were found to be well above the water quality guidelines there by promoting eutrophication. / Environmental Sciences / M. Sc. (Environmental Management)

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