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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.
1

Assessing the impact of urbanization on White River water and sediment geochemistry in an agricultural watershed

Snidow, Dean C. January 1900 (has links)
Thesis (M.S.)--Ball State University, 2009. / Title from PDF t.p. (viewed on Feb. 08, 2010). Includes bibliographical references (p. 37-38).
2

The effects of restoration structures on nutrient uptake and macroinvertebrate communities in restored urban streams in Greensboro, North Carolina

Hines, Stacy Lynn. January 2007 (has links) (PDF)
Thesis (M.S.)--University of North Carolina at Greensboro, 2007. / Title from PDF t.p. (viewed Mar. 10, 2008). Directed by Anne E. Hershey; submitted to the Dept. of Biology. Includes bibliographical references (p. 33-39).
3

Quantifying the presence of current-use insecticides and toxicity of sediments in urban residential watersheds in central Texas

Hintzen, Emily P. Belden, Jason B. January 2007 (has links)
Thesis (M.S.)--Baylor University, 2007. / Includes bibliographical references (p. 44-46).
4

Trophic patterns of an insectivorous bat community foraging over urban and pristine streams as revealed by stable isotope and fecal analyses

Shiflet, Lindsey Ann. January 2007 (has links) (PDF)
Thesis (M.S.)--University of North Carolina at Greensboro, 2007. / Title from PDF t.p. (viewed Mar. 10, 2008). Directed by Matina C. Kalcounis-Rüppell; submitted to the Dept. of Biology. Includes bibliographical references (p. 24-29).
5

Towards an integrated approach to urban watershed planning : linking vegetation patterns, human preferences, and stream biotic conditions in the Puget Sound lowland /

Shandas, Vivek. January 2006 (has links)
Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 140-171).
6

Composition and Dispersal Dynamics of Vegetation Communities in Urban Riparian Forests

von Behren, Christa 08 June 2018 (has links)
In urban riparian areas, vegetation composition may be affected by urban land use changes at both the stream reach and the watershed scale. Moreover, the mechanisms by which seeds disperse may be affected both by reduction in seed sources due to vegetation removal and by the urban stream syndrome that produces flashier hydrographs and incised channels. I hypothesized that vegetation communities with high cover of native and hydrophilic species would be found in watersheds with high forest cover, while more limited cover of these species would be found in highly developed watersheds. Additionally, to examine the dispersal mechanisms contributing to these patterns, I hypothesized that 1) more seeds would be deposited in riparian areas by water than by wind; 2) the number of seeds deposited by streams would decrease as watershed urbanization increased; and 3) seeds deposited in the most urbanized sites would be primarily from species with traits favoring deposition by water, including large seed size and presence of a dispersal appendage. To investigate relationships between urban land cover types and riparian vegetation, I surveyed 30 randomly-selected riparian forests in the Portland-Vancouver metro area and related vegetation assemblages to watershed land cover. Vegetation was mapped to the nearest 1cm along three transects in each site. Land cover was characterized both within a 500m buffer around each site, and within the entire watershed. Relationships between land cover and vegetation assemblages were investigated using nonmetric multidimensional scaling and classification trees. To investigate the effect of watershed urbanization intensity on riparian seed deposition, I collected seeds deposited in nine riparian sites along a gradient of watershed total impervious area (TIA). I used a stratified-random approach to select sites. In each site, wind-deposited seeds were collected in funnel traps three times, and water-deposited seeds were collected in turf traps four times, over a 15-month period, spanning both wet and dry seasons. Consistent with my first hypothesis, communities dominated by native understory species were found exclusively in watersheds that were at least 15% forested by evergreen canopy. These findings suggest that native understory communities can persist in urban areas if adequate surrounding forest cover is maintained. Regarding my second major hypothesis, significantly more seeds were deposited by water than by wind (p < 0.05; mean of 155 seeds per turf trap; mean of 30 seeds per funnel trap). For shrubs, for species primarily dispersed by animals, and for species under 15m tall, hydrochory significantly increased delivery to riparian areas over the background seed delivery rate measured in funnel traps. There was a significant reduction in the number of seeds deposited by streams as TIA increased (adjusted R² = 0.74; p < 0.01). Deposition of shade-tolerant seeds decreased significantly, while deposition of non-native seeds increased significantly (p < 0.05) with watershed TIA and with development within 500m from the site, likely due to alterations of seed source pools of these species. Findings indicate that in an urban setting, small streams have the capacity to act as dispersal vectors, connecting fragmented populations that may otherwise be seedlimited. Riparian forests with diverse understory assemblages maintained by ongoing seed deposition may persist in urban areas with sufficient watershed forest, as well as with low development cover, in both the whole watershed and the near-stream area. Total seed deposition by streams, as well as deposition of shade-tolerant species, can be expected to decrease with increased watershed development. Results suggest that passive approaches to restoration of riparian forest understories in urban watersheds will only likely be successful with sufficiently high forest cover and with restricted development.
7

Mercury distribution in soils and stream sediments of central Indiana, USA /

Hatcher, Carrie Lynn. January 2009 (has links)
Thesis (M.S.)--Indiana University, 2009. / Department of Earth Sciences, Indiana University-Purdue University Indianapolis (IUPUI). Advisor(s): Gabriel Filippelli, Kathy Licht, Pierre Jacinthe. Includes vita. Includes bibliographical references (leaves 74-77).
8

Aplicação de Sistema de Informações Geográficas (SIG) para modelagem de eventos críticos de vazão em uma microbacia urbana / Application of Geographical Information System (GIS) paragraph Events Modeling flow Critics in An urban watershed

Felizardo, Lucas Menezes [UNESP] 01 February 2016 (has links)
Submitted by LUCAS MENEZES FELIZARDO null (lucas_menfel@aluno.feis.unesp.br) on 2016-10-20T17:08:51Z No. of bitstreams: 1 Lucas Felizardo 4.pdf: 4057715 bytes, checksum: d731799585df721c5ec0ec455b5d3418 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-10-26T18:42:24Z (GMT) No. of bitstreams: 1 felizardo_lm_me_ilha.pdf: 4057715 bytes, checksum: d731799585df721c5ec0ec455b5d3418 (MD5) / Made available in DSpace on 2016-10-26T18:42:24Z (GMT). No. of bitstreams: 1 felizardo_lm_me_ilha.pdf: 4057715 bytes, checksum: d731799585df721c5ec0ec455b5d3418 (MD5) Previous issue date: 2016-02-01 / Com o aumento da população mundial e com sua concentração cada vez maior no meio urbano uma gama de problemas vem se apresentando relacionado a esse aumento populacional de maneira direta ou indireta, esse êxodo das pessoas para os grandes centros urbanos vem alterando o espaço geográfico desse ambiente bem rapidamente, principalmente na região do sudeste brasileiro onde os processos de industrialização são mais evidentes. Com essa migração a ocupação e o uso do solo vêm sendo ocupada nem sempre da forma que os planos diretores das cidades recomendam proporcionando na maioria dos casos impactos negativos nos recursos naturais. As alterações antrópicas realizadas nessas áreas, como desmatamento e a urbanização, estão promovendo um desequilíbrio ao meio ambiente afetando áreas drenadas pelas bacias hidrográficas, a complexidade do ambiente urbano e de sua infraestrutura de drenagem tem uma influência inerente no escoamento superficial, este escoamento gera inundações urbanas, que impõe desafios à modelagem, a simulação destes cenarios exigem dados detalhados de elevação. Os problemas acarretados pela ocupação desordenada da bacia vêm sendo abordados em inúmeros estudos de casos que demonstram que o uso e ocupação do solo de forma inadequada e desordenada, muitas vezes, com obras mal dimensionadas, acarretam grandes prejuízos socioeconômicos. O planejamento integrado de uma bacia urbana é o único meio de viabilizar seus usos, sem que isso acarrete em um maior desequilíbrio do meio físico, e nesse cenário que com os dados de obtidos da bacia do Córrego do Mineirinho foi feito a modelagem de cenários de eventos de precipitação e seus possíveis efeitos no meio físico com compilações e um único software. O córrego do mineirinho e outras bacias da região já vem sendo estudadas por inúmeros pesquisadores seus resultados obtidos com múltiplas ferramentas computacionais se mostram compatíveis com os que obtivemos com o uso de apenas um software para realizar todas as fases do processo desde o pré-processamento de imagens de satélite a produção de modelos em 3D de inundação de eventos de precipitação em inúmeros cenários. / With the increasing world population and its increasing concentration in urban areas a range of issues has been presented related to this population increase directly or indirectly, this exodus of people to large urban centers is changing the geographic space that environment very quickly, especially in the Brazilian southeast region where industrialization processes are most evident. With this migration the occupation and land use have been busy not always the way the master plans of cities recommend providing in most cases negative impacts on natural resources. Anthropogenic changes made in these areas, as deforestation and urbanization, are promoting an imbalance to the environment affecting the watershed drained areas, the complexity of the urban environment and its drainage infrastructure has an inherent influence on runoff, this flow generates floods urban, which poses challenges to modeling. The simulation of these scenarios require detailed elevation data. The problems posed by irregular occupation of the basin have been addressed in numerous studies that demonstrate that the use and occupation of inappropriate and disorderly manner, often with poorly scaled works, present major socioeconomic losses. Integrated planning of an urban basin is the only means of enabling their uses, without incurring a greater imbalance in the physical environment, and in this scenario with data obtained from Mineirinho Stream basin was made scenario modeling precipitation events and their potential effects on the physical environment with a unique compilations and software. The stream Mineirinho and other basins in the region has already been studied by numerous researchers their results with multiple computational tools to show compatible with those obtained using only one software to perform all phases of the process from the pre-processing satellite images to produce 3D models of flood precipitation events in many scenarios.
9

Aplicação de Sistema de Informações Geográficas (SIG) para modelagem de eventos críticos de vazão em uma microbacia urbana /

Felizardo, Lucas Menezes January 2016 (has links)
Orientador: Jefferson Nascimento de Oliveira / Resumo: Com o aumento da população mundial e com sua concentração cada vez maior no meio urbano uma gama de problemas vem se apresentando relacionado a esse aumento populacional de maneira direta ou indireta, esse êxodo das pessoas para os grandes centros urbanos vem alterando o espaço geográfico desse ambiente bem rapidamente, principalmente na região do sudeste brasileiro onde os processos de industrialização são mais evidentes. Com essa migração a ocupação e o uso do solo vêm sendo ocupada nem sempre da forma que os planos diretores das cidades recomendam proporcionando na maioria dos casos impactos negativos nos recursos naturais. As alterações antrópicas realizadas nessas áreas, como desmatamento e a urbanização, estão promovendo um desequilíbrio ao meio ambiente afetando áreas drenadas pelas bacias hidrográficas, a complexidade do ambiente urbano e de sua infraestrutura de drenagem tem uma influência inerente no escoamento superficial, este escoamento gera inundações urbanas, que impõe desafios à modelagem, a simulação destes cenarios exigem dados detalhados de elevação. Os problemas acarretados pela ocupação desordenada da bacia vêm sendo abordados em inúmeros estudos de casos que demonstram que o uso e ocupação do solo de forma inadequada e desordenada, muitas vezes, com obras mal dimensionadas, acarretam grandes prejuízos socioeconômicos. O planejamento integrado de uma bacia urbana é o único meio de viabilizar seus usos, sem que isso acarrete em um maior desequilíbrio do me... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre
10

Sources, Transport, Measurement and Impact of Nano and Microplastics in Urban Watersheds

Birch, Quinn T. January 2019 (has links)
No description available.

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