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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

The Dynamic Stormwater Reponse of a Green Roof

Martin, Bruce 03 March 2009 (has links)
Impervious surfaces negatively affect urban hydrology by altering the depth, frequency and seasonal distribution of stormwater runoff. To assess the imperviousness of green roofs, a mathematical model was developed to simulate the stormwater response of a hypothetical green roof. The model is based on the physical processes that affect the green roof stormwater response and uses historic climate data. The results show that green roof imperviousness fluctuated according to climate conditions and precipitation sequence. Only 29% of the total precipitation received by the green roof resulted in runoff, however, the response varied substantially when evaluated at a daily interval. Runoff was eliminated during 82% of days with rain and a higher proportion of runoff disturbances were eliminated during the spring and summer compared to the fall. In comparison to an impervious surface, the green roof showed a reduction in the depth and frequency of runoff thereby improving urban hydrology.
2

Estimating Impervious Surface Cover in Flathead County, Montana

Skeen, James Andrew 22 June 2017 (has links)
Northwest Montana has seen a significant increase in its population in the past twenty years. The increase in population, and associated development, is thought to be associated with "amenity migration"; people moving to an area to exploit the recreational opportunities that are unique to that area. Impervious surfaces can serve as a suitable proxy for tracking the spread of various anthropogenic influences on an ecosystem; it impacts groundwater recharge, increases overall surface runoff as well as pollution and sediment load, and fragments landscapes. In this study, an Artificial Neural Network model was developed to update NLCD impervious surface product (2011) in Flathead County, Montana. Four Landsat 8 images from 2015 and 2016 were used to characterize imperviousness. This multi-temporal analytical method was designed to reduce the spectral confusion between impervious surface and soil/agricultural lands. We compared the neural network-predicted impervious surface maps with 2011 NLCD. When all four neural network prediction images agreed with a change of 50% or more from the 2011 NLCD map, the average of those four images replaced that pixel from the 2011 imperviousness map. Compared to the ground truth, the method used showed significant promise, with an R2 of 0.73 and RMSE of 0.123. A comparison of the artificial neural network model results and the 2011 NLCD data showed a continuation of urbanization trends; the urban cores of towns in the study remain static while the majority of impervious surface development takes place along the perimeter of urban areas. / Master of Science / Remotely sensed Landsat data can be used to rapidly detect and estimate changes in impervious surface cover. This study used artificial neural networks in conjunction with the National Landcover Database’s 2011 Percent Developed Imperviousness layer and Landsat 8 data from four dates between the summer of 2015 and fall of 2016 to predict impervious surface cover in 2016, by deriving spectral relationships between Landsat data and impervious surfaces. We found that by requiring agreement between the four dates’ neural networks outputs, we eliminated many of the false positives that arose from exposed soil. Using this method, we achieved an R2 of 0.73 and RMSE of .123, sampling only the areas along a rural-urban gradient, in an area with significant seasonal spectral variability.
3

A Comparison of Imperviousness Derived from a Detailed Land Cover Dataset (DLCD) versus the National Land Cover Dataset (NLCD) at Two Time Periods

Cooper, Brandon Elliott 01 September 2016 (has links)
To address accuracy concerns of the National Land Cover Dataset (NLCD), this case study compares impervious surface from the NLCD to a Detailed Land Cover Dataset (DLCD) for the Town of Blacksburg, Virginia over two time periods (2005/2006 and 2011) at spatial aggregation scales (fine to coarse) and scopes (site-specific to area-extent). When comparing the total impervious surface area, the NLCD overestimated the DLCD by appreciable amounts (12-27%) for the entire town and across all specified land use zones for both time periods examined. A binary pixel-wise accuracy assessment of impervious surface revealed that the NLCD performed well for all scopes except for the single family land use zone (user accuracy <40%). The spatial aggregation of pixels to 90-m led to improved agreement between the two datasets. Using the DLCD as a reference, an empirical normalization equation was successfully applied to the NLCD to further reduce overestimation and data skewness. / Master of Science / To address accuracy concerns of the National Land Cover Dataset (NLCD), this case study compares impervious surface conditions from the NLCD to a Detailed Land Cover Dataset (DLCD) for the Town of Blacksburg, Virginia over two time periods (2005/06 and 2011) at various spatial scales and scopes. When comparing the total impervious surface area, the NLCD overestimated the DLCD by appreciable amounts for the entire town and across all specified land use zones for both time periods examined. A comparison at the pixel level revealed the NLCD performed well for all scopes except for the single family residential land use zone. Although there was improved agreement between the datasets at coarser resolutions, data skewness was still apparent. By using the DLCD as a ground truth reference, a mathematical correction equation was applied to the NLCD to better align it with the DLCD. Reflected through this assessment, inaccuracies within the NLCD need to be further studied to assist local and regional governments to more correctly depict land cover conditions for applications such as land use planning and stormwater management.
4

Evaluating the Effects of Green Roofs as Tools for Stormwater Management in an Urban Metropolis

Polinsky, Robyn R. 01 December 2009 (has links)
Stormwater management is an essential aspect of urban hydrology. Urbanized areas have large amounts of impervious surface cover (ISC) and well developed sewer and drainage networks which rapidly channel water and pollutants off of streets and into local streams. This research evaluates the use of vegetated roofs as mechanisms to reduce ISC and stormwater runoff in downtown Atlanta. A 3-D model of the study site was created so that runoff rates could be measured for various rooftop scenarios under different size storm events. The results revealed a reduction in peak runoff and an increase in both the lag time and duration of response time. The results were most significant for the smallest storm event with 2/3 of the rooftops vegetated. As these experiments use a scale model for a section of downtown Atlanta, results are likely to be applicable to similar urban environments and may provide guidance for stormwater engineers.
5

Urbanization and flooding in Accra, Ghana

Afeku, Kizito. January 2005 (has links)
Thesis (M.A.)--Miami University, Dept. of Geography, 2005. / Title from first page of PDF document. Document formatted into pages; contains [1], v, 53 p. : ill. Includes bibliographical references (p. 50-53).
6

A necessidade da reserva de área para o armazenamento de água no início do crescimento urbano

Juchem, José Ricardo January 2002 (has links)
Atualmente, o desenho urbano tem sido realizado dentro de um âmbito restrito do conhecimento. Este não tem considerado aspectos de drenagem da água que trazem grandes transtornos e custos para a sociedade e o ambiente. O desenvolvimento urbano brasileiro tem produzido um aumento significativo na freqüência de inundações, na produção de sedimentos e na deterioração da qualidade da água. Tal situação é decorrente, na maioria dos casos, da ocupação intensiva do solo urbano. Assim, essa abordagem demonstra, inicialmente, uma visão sobre o desenho urbano e suas interfaces; particularmente as relacionadas com a geografia, o ambiente natural e o construído. Na seqüência, pretendendo atingir o enfoque interdisciplinar, aponta vínculos entre o desenho urbano e a hidrologia através de uma análise ambiental de bairros dos municípios de Porto Alegre e Lindolfo Collor, de modo a identificar relações com a utilização de uma variável - a superfície impermeável, procurando descrever o comportamento ambiental de bacias hidrográficas urbanizadas bem como mostrar a necessidade da reserva de área para armazenar água no início do crescimento urbano. Finalizando, apresenta os principais parâmetros ou características de desenho que deverão garantir a sustentabilidade urbana e hidrológica. Apesar de prematuro, pode-se afirmar que existem indícios para que a dissertação venha suprir algumas deficiências existentes no planejamento urbano-ambientalatualmente adotado. / Actually, the urban design has been realized in the restrict scope of knowledge. It hasn't considered drainage aspects that provide large disturbances and difficulties to society and the environment. The Brazilian urban development has produced significant increase in the flooding frequency, in the sediments produce and water quality. This situation result from, in the majority of cases, the intensive occupation of urban ground. Therefore this subject show the vision about urban design and the interfaces: specially the relation between geography, natural environmental and builded environmental. In the next time, intending to affect the interdisciplinary subject, show bonds between urban design and hydrology through design study in Porto Alegre City and Lindolfo CollorCity to identifythe relationwith a variable- impervious surface, looking for describe the environmental behavior from watershed and show the necessity of water reserve in the beginning urban development. Finally, shows a proposal of sustainability urban design that integrate urban planning and hydrology. Represent a new aspect to come providing some definitions actually adopted in the urban environmental planning.
7

A necessidade da reserva de área para o armazenamento de água no início do crescimento urbano

Juchem, José Ricardo January 2002 (has links)
Atualmente, o desenho urbano tem sido realizado dentro de um âmbito restrito do conhecimento. Este não tem considerado aspectos de drenagem da água que trazem grandes transtornos e custos para a sociedade e o ambiente. O desenvolvimento urbano brasileiro tem produzido um aumento significativo na freqüência de inundações, na produção de sedimentos e na deterioração da qualidade da água. Tal situação é decorrente, na maioria dos casos, da ocupação intensiva do solo urbano. Assim, essa abordagem demonstra, inicialmente, uma visão sobre o desenho urbano e suas interfaces; particularmente as relacionadas com a geografia, o ambiente natural e o construído. Na seqüência, pretendendo atingir o enfoque interdisciplinar, aponta vínculos entre o desenho urbano e a hidrologia através de uma análise ambiental de bairros dos municípios de Porto Alegre e Lindolfo Collor, de modo a identificar relações com a utilização de uma variável - a superfície impermeável, procurando descrever o comportamento ambiental de bacias hidrográficas urbanizadas bem como mostrar a necessidade da reserva de área para armazenar água no início do crescimento urbano. Finalizando, apresenta os principais parâmetros ou características de desenho que deverão garantir a sustentabilidade urbana e hidrológica. Apesar de prematuro, pode-se afirmar que existem indícios para que a dissertação venha suprir algumas deficiências existentes no planejamento urbano-ambientalatualmente adotado. / Actually, the urban design has been realized in the restrict scope of knowledge. It hasn't considered drainage aspects that provide large disturbances and difficulties to society and the environment. The Brazilian urban development has produced significant increase in the flooding frequency, in the sediments produce and water quality. This situation result from, in the majority of cases, the intensive occupation of urban ground. Therefore this subject show the vision about urban design and the interfaces: specially the relation between geography, natural environmental and builded environmental. In the next time, intending to affect the interdisciplinary subject, show bonds between urban design and hydrology through design study in Porto Alegre City and Lindolfo CollorCity to identifythe relationwith a variable- impervious surface, looking for describe the environmental behavior from watershed and show the necessity of water reserve in the beginning urban development. Finally, shows a proposal of sustainability urban design that integrate urban planning and hydrology. Represent a new aspect to come providing some definitions actually adopted in the urban environmental planning.
8

A necessidade da reserva de área para o armazenamento de água no início do crescimento urbano

Juchem, José Ricardo January 2002 (has links)
Atualmente, o desenho urbano tem sido realizado dentro de um âmbito restrito do conhecimento. Este não tem considerado aspectos de drenagem da água que trazem grandes transtornos e custos para a sociedade e o ambiente. O desenvolvimento urbano brasileiro tem produzido um aumento significativo na freqüência de inundações, na produção de sedimentos e na deterioração da qualidade da água. Tal situação é decorrente, na maioria dos casos, da ocupação intensiva do solo urbano. Assim, essa abordagem demonstra, inicialmente, uma visão sobre o desenho urbano e suas interfaces; particularmente as relacionadas com a geografia, o ambiente natural e o construído. Na seqüência, pretendendo atingir o enfoque interdisciplinar, aponta vínculos entre o desenho urbano e a hidrologia através de uma análise ambiental de bairros dos municípios de Porto Alegre e Lindolfo Collor, de modo a identificar relações com a utilização de uma variável - a superfície impermeável, procurando descrever o comportamento ambiental de bacias hidrográficas urbanizadas bem como mostrar a necessidade da reserva de área para armazenar água no início do crescimento urbano. Finalizando, apresenta os principais parâmetros ou características de desenho que deverão garantir a sustentabilidade urbana e hidrológica. Apesar de prematuro, pode-se afirmar que existem indícios para que a dissertação venha suprir algumas deficiências existentes no planejamento urbano-ambientalatualmente adotado. / Actually, the urban design has been realized in the restrict scope of knowledge. It hasn't considered drainage aspects that provide large disturbances and difficulties to society and the environment. The Brazilian urban development has produced significant increase in the flooding frequency, in the sediments produce and water quality. This situation result from, in the majority of cases, the intensive occupation of urban ground. Therefore this subject show the vision about urban design and the interfaces: specially the relation between geography, natural environmental and builded environmental. In the next time, intending to affect the interdisciplinary subject, show bonds between urban design and hydrology through design study in Porto Alegre City and Lindolfo CollorCity to identifythe relationwith a variable- impervious surface, looking for describe the environmental behavior from watershed and show the necessity of water reserve in the beginning urban development. Finally, shows a proposal of sustainability urban design that integrate urban planning and hydrology. Represent a new aspect to come providing some definitions actually adopted in the urban environmental planning.
9

Urbanization and Flooding in Accra,Ghana

Afeku, Kizito 08 August 2005 (has links)
No description available.
10

Autonomous Vehicles: changing the surface landscape of communities through increased green infrastructure adoption and implementation to help US cities combat stormwater runoff

Schmidt, Kelsey L. 24 September 2018 (has links)
No description available.

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