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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.
11

Qualidade da água do escoamento superficial urbano: revisão visando o uso local. / Water quality from initial urban run-off: revision seeking local use.

Maria Carolina Rivoir Vivacqua 15 April 2005 (has links)
O presente trabalho, dissertação visando a obtenção do titulo de mestrado em engenharia na Escola Politécnica da Universidade de São Paulo, é fruto de pesquisa bibliográfica de dados secundários de pesquisa de campo sobre qualidade de águas de chuva após os primeiros escoamentos superficiais. A pesquisa procurou propor e discutir o conceito de uso da água de escoamentos superficiais próximos, como uma das ferramentas para o desenvolvimento e implantação de empreendimentos e programas de gerenciamento de águas. São apresentados e analisados alguns estudos, internacionais selecionados, de qualidade com identificação e quantificação de poluentes de águas provenientes de telhados, pátios e jardins, de ruas e provenientes de áreas maiores como bairros. A análise de resultados das dez pesquisas selecionadas, ao final, possibilitou o conhecimento geral da qualidade de águas da drenagem urbana em seus primeiros momentos. Foi possível, igualmente, identificar usos para essas águas, que revelam-se como mais um manancial de interesse econômico e ambiental, com qualidade. A análise dos estudos permitiu concluir que uso de água de escoamentos superficiais próximos, ou seja água captada em locais próximos a incidência da chuva, é ferramenta básica para o desenvolvimento de empreendimentos que visem a economia de água tratada bem como visem melhorias ambientais. / This work was conducted aiming a master degree in Engeneering in Escola Politécnica of Universidade de São Paulo, and deal with secondary data obtained in field’s researches about rain water quality in the initial run-off. This research intended to propose and to discuss the concept of use of the water from initial run-off, as one of the tools to develop and implant achievement and management programs of waters. It is presented and analyzed some international studies of quality with measure of pollutant components in water obtained from roofs, backyards and gardens, from streets and from bigger areas like several blocks. The date analysis of ten researches selected leads to the improving of the general knowledge of the urban drainage waters quality in its first run-off. This academic work produced, in the same way, the identification of uses for the rain water after first run-off, which was reveled as a source of economic and environmental interest. Analyzing the studies allowed conclude that the use of water after first run-off is basic tool for the development of achievements that seek the economy of treated water as well as environmental improvements.
12

Evaluating uncertainty in water resources estimation in southern Africa : a case study of South Africa /

Sawunyama, Tendai January 2008 (has links)
Thesis (Ph.D. (Institute for Water Research)) - Rhodes University, 2009.
13

[en] STATE SPACE MODELS FOR IBNR RESERVES ESTIMATION: ROW-WISE STACKING THE RUNOFF TRIANGLE / [pt] ESTIMAÇÃO DE RESERVAS IBNR POR MODELOS EM ESPAÇO DE ESTADO: EMPILHAMENTO POR LINHAS DO TRIÂNGULO RUNOFF

RODRIGO SIMOES ATHERINO 15 June 2009 (has links)
[pt] Este trabalho versa sobre previsão de reservas do tipo IBNR levando-se em conta uma ordenação diferente do triângulo de runoff incremental. Esta se dá por linhas empilhadas, originando, assim, uma série temporal univariada repleta de valores faltantes, cuja soma desses valores constitui o IBNR a ser estimado. Duas abordagens de estimação, inteiramente baseadas na teoria dos modelos em Espaço de Estado e do filtro de Kalman, são desenvolvidas, implementadas com dados reais de empresas seguradoras, e comparadas entre si e a outros métodos de estimação já consagrados na literatura atuarial. A primeira abordagem pauta-se no cálculo da matriz de covariâncias condicionais das componentes do IBNR, e a segunda é um processo de obtenção do IBNR por acumulação. Os resultados obtidos revelam, para as abordagens propostas, os seguintes pontos sumários: (i) plena eficiência e viabilidade computacional; (ii) sistemático ganho em termos de acurácia do IBNR estimado; e (iii) abrangência no que diz respeito às possibilidades de modelagem estatística dos dados de IBNR. / [en] This work deals with prediction of IBNR reserves under a different ordering of the non-cumulative runoff triangle. This is accomplished by stacking the rows, which results in a univariate time series with several missing values, whose corresponding sum is in fact the IBNR. Two estimation approaches, entirely based on state space methods and Kalman filtering, are developed, implemented with real data, and compared with some well established estimation methods for IBNR. The first approach consists in obtaining the conditional covariance matrix of the IBNR components, and the second tackles the IBNR estimation under an accumulation process. Three remarks emerge from the empirical results: (i)computational feasibility and efficiency; (ii)precision improvement for IBNR estimation; and (iii)flexibility in which concerns the IBNR modelling framework.
14

The Effect of Roadside Elements on Driver Behavior and Run-Off-the-Road Crash Severity

Fitzpatrick, Cole D 01 January 2013 (has links) (PDF)
Roadside vegetation provides numerous environmental and psychological benefits to drivers. Previous studies have shown that natural landscapes can effectively lower crash rates and cause less stress and frustration to the driver. However, run-off-the-road crashes resulting in a collision with a tree are twice as likely to result in a fatality, thus reinforcing the need to examine the placement of vegetation within the clear zone. This study explores the relationship between the size of the clear zone and the presence of roadside vegetation on selected driver attributes, including both driver speed and lateral positioning. To evaluate the effect on the driver speed selection process, a static evaluation was employed. Completed by more than 100 drivers, the static evaluation was utilized to gather speed selections on both real and virtual roads containing four combinations of clear zone size and roadside vegetation density. Additionally, field data was collected to validate the findings of the static evaluation and to determine the extent to which roadside vegetation impacts driving attributes. When presented with a large clear zone, drivers positioned the vehicle further from the edge of the road as the vegetation density increased. Furthermore, the speeds observed in the field correlated with the speeds that participants selected when watching a video of the same road. Finally, the UMassSafe Traffic Safety Data Warehouse was utilized to link crash and roadway data, allowing for an in-depth analysis of run-off-the-road (ROR) crash severity. The results of this study further demonstrate the nature of the relationship between clear zone design and driver behavior.
15

Use Of Near-Zero Leachate Irrigation Systems For Container Production Of Woody Ornamental Plants

Sammons, Jonathan D. January 2008 (has links)
No description available.
16

Peak Discharge Estimation for Rural Areas Using APSWM and OTTHYMO Models

Dai, Jianping 01 1900 (has links)
<p>Traditional methods for flood estimation can be categorized as (1) simplified methods, e.g., regression analysis, (2) frequency analysis of streamflow data, (3) design storm-based precipitation-runoff modeling, and ( 4) continuous precipitation-runoff simulation modeling. The new approach - the Analytical Probabilistic Stormwater Model - was developed as an alternative to provide an efficient way of getting realistic estimation of peak discharges of desired frequencies for use in stormwater management of urban areas. To extend APSWM's application to rural areas, a series of comparisons were made between the calibrated design storm-based OTTHYMO model results, frequency analysis results and APSWM results for the Ganaraska River watershed. Special considerations were given to the transformation of the input parameter values of OTTHYMO model to those of APSWM. Comparable results were obtained for large floods, while APSWM may underestimate peak discharges of low return periods. Upon further testing and development, APSWM may be used for large rural areas.</p> / Thesis / Master of Engineering (MEngr)
17

Park Park Fabric Landscape: Landscape Systems Give Form to Architecture

Surla, Sean O'Dell 26 May 2006 (has links)
Today, throughout the world, we are in the midst of a man-made environmental crisis. We must change how we consume and affect natural resources on the planet if we are to retain its richness of landscapes and biodiversity. It is our job as landscape architects to lead the way in changing the human relationship to natural resource consumption and building. My thesis asks the question, how can an understanding of landscape as a system give form to architecture? In natural systems nothing is wasted, everything is interconnected and self-sufficient at the same time. How can we model our buildings -- our built landscapes -- after nature? Three natural systems are key components to modeling nature: water, vegetation and energy. The landscapes that we have constructed for cars exemplify the problems we have ecologically. Cars produce greenhouse gases creating global warming. Highways and parking lots denude the vegetative habitat and lead to excessive water runoff polluting the watersheds. Solving the car problem goes a long way to setting an example for ultimately resolving ecological development issues. Cars are both the epitome of freedom and environmental degradation. Joni Mitchell put it eloquently with "they paved paradise put up a parking lot." My studio project is a mixed use parking facility fabricating the natural systems of water, energy and vegetation in order to mitigate environmental problems as well as resolve the practical necessity of where to put cars in crowded urban centers. Park Park puts the paradise back into the pavement. / Master of Landscape Architecture
18

Optimisation and valuation of water use in Scotland

Köseoğlu, Münire Nazlı January 2018 (has links)
Valuation draws heavily on the economic theory of demand. This tells us that users have preferences for water and are willing to pay different amounts for units of water put to different uses. Water should be allocated between these uses to the point that equalises the value of the last or 'marginal' unit. In other words, it is impossible to find a higher value for this marginal unit. Application of this principle of equi-marginal returns requires us to have some clarity about water values in competing uses. This is also important since water is rarely free to supply, and therefore suppliers need to charge a price that is in some sense equal to the supply cost and value to achieve full cost recovery. Even though inclusion of this economic rationale in the management of water resources has been a widely accepted principle, and is included in national and the EU policies, the actual practice does not fully reflect this endorsement. While many countries recognise the vital nature of water resources, few, if any, pursue a rigorous analysis of revealing the explicit value of water as a basis for determining whether water is actually being allocated to sectors in order to maximise its overall benefit to society. Aspiring to be the first Hydro Nation, maximising the social return from its water uses ought to be a policy objective in Scotland. This thesis constructs a portfolio of different water uses, estimating the approximate value for each and their current allocation in Scotland. This aims to stimulate an informed debate on actual allocation of water among different uses, relative values and trade-offs of these allocations in Scotland so that alternative allocation scenarios can also be discussed. I then focus on the valuation of water by manufacturing industries, the biggest consumptive use and a significant added value creator in Scotland. I investigate the factors that affect the valuation of water and the responsiveness to prices in manufacturing industries using a meta-analysis technique. These values are obviously not the same for each manufacturing sector due the nature of their use and value of their final output. Some sectors create premium value out of their use. The whisky industry stands out as a water-intensive and high value creating sector, as well as a vital contributor to the rural and overall Scottish economy. It is analysed here as the first case study using water footprint and marginal productivity analyses methods, both analyses highlighting the importance of quality and quantity of local water resources in Scotland and its value to the industry. The second case study is the livestock industry, which has been overlooked in the valuation of water use literature yet is significant for livelihoods in rural Scotland where reduced land capability limits agricultural production options. Following the portfolio of water uses, meta-analysis and case studies that analyse the current situation of value and allocation, I explore how the current situation can be improved through the application of tradability. Currently the main problem in Scotland is not the amount of water used or abstracted, but the pollution reaching water bodies as the result of run-off and leaching from agricultural fields. Therefore, the feasibility of trading water rights is more concerned with the permits to pollute rather than the rights to use. Using a linear optimisation I look into the potential of designing a payment for ecosystem services scheme based on tradability of water pollution in agricultural catchments that are affected by from diffuse pollution. The results indicate that trading schemes help reduce the cost of pollution to all users while creating additional income for farms. For constructing more precise pollution rights and robust schemes more research efforts are required.
19

Evaluation of Roadside Collisions with Utility Poles and Trees at Intersection Locations

Mattox, Todd Berry 15 November 2007 (has links)
The United States averages 40,000 traffic fatalities annually. The American Association of State Highway and Transportation Officials (AASHTO) Roadside Design Guide cites run-off-the-road crashes as contributing greatly to this statistic, with about one-third of all traffic deaths [1]. This number has remained relatively constant over the past four decades, and despite a major increase in vehicle miles traveled (VMT), the rate of fatalities per 100 million vehicle miles traveled has declined. However, this relatively large number of run-off-the-road crashes should remain a major concern in all roadway design. The Highway Safety Act of 1966 marks a defining moment in the history of roadside safety [ ]. Before this point, roadways were only designed for motorists who remained on the roadway, with no regard for driver error. As there was no legislation or guidelines concerning roadside design, roadways constructed prior to 1966 are littered with fixed objects directly off of the edge of pavement. Fortunately, many of these roads have reached their thirty year design lives and have become candidates for improvement. The following report examines roadside crashes on nine Atlanta urban arterial roadways. Accident type, severity, and location for all crashes on these were evaluated. It is found roadside collisions with utility poles and trees were more prone to occur at intersection locations than midblock locations. Also for the studied roadway corridors, on average, roadside collisions were more likely to result in serious injury or fatality. Based on these findings initial recommendations are offer for improving clear zone requirements.
20

Modeling Roadside Safety Hazards to Predict Annual Crash Cost to Encroaching Vehicles in Rural Road Networks

Delgado, Isidro 01 January 2011 (has links)
Roadside crashes account for a large portion of total fatal crashes that occur annually in the United States. About 30% of those fatalities are the result of single vehicle run-off-road crashes. A large proportion of these fatal crashes occur in rural roads when vehicles depart from the travel lane and collide with trees or other roadside safety hazards. Many of these run-off-road accidents occur in local roads that carry traffic volumes between 1,000 and 20,000 vehicles per day. Many of these roads are part of the jurisdiction of county authorities faced with the dilemma of having too many "potentially dangerous" sites and lacking a methodology for assessing their risk to rank them accordingly; and to apply the limited resources to the ones that will bring the greatest benefit to society. This situation describes the case in Hillsborough County, Florida, in 2004 when they contracted a study with the Transportation Program of the Department of Civil and Environmental Engineering of the University of South Florida. The initial scope was to develop a methodology to assess the potential risk for each of 19 sites in a given list to prioritize further studies. The project was sponsored by the Engineering Division, Public Works Department, of Hillsborough County. The methodology developed considered the roadside safety hazards at each location and it was based on the use of the Road Safety Analysis Program (RSAP) software distributed as part of the 2002 AASHTO's Roadside Design Guide. This dissertation presents a further development of this approach: it continues to use the probabilistic approach built into RSAP to calculate the annual crash cost of each roadside safety hazard at 45 study segments. It then obtains regression models to predict that annual crash cost, as computed by RSAP, based on roadway and traffic characteristics as well as on the nature, location and physical dimensions of the roadside safety hazard. For each study segment, the annual crash cost of each feature (as estimated with the models developed) is added for a final comparison with the RSAP Annual Crash Cost. A coefficient of determination (R2) of 0.80 was obtained. The models developed were finally used to replicate the original 2005 study for Hillsborough County. Although there were minor variations on the risk index originally computed, the ranking of the 19 study sites remained basically the same with a clear cut indication of the sites that should be considered for further engineering studies.

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