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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.
101

Modelling the effects of land-use change on existing stormwater infrastructure: a case study of Tshwane.

Ndlovu, Hosana Hossain. January 2013 (has links)
M. Tech. Engineering: Civil. / Aims to determine the change in run-off as a result of change in land management and to model the effect of land-use change on stormwater generation. The developement a management tool that effectively deals with the consequences.
102

Reducing combined sewage overflows : the essentials of a sustainable stormwater management plan

Stern, Zachary Elfonte 25 July 2011 (has links)
This report examined efforts to manage combined sewage overflows and create effective stormwater management plans. To provide background on the issue, a brief history of sewage management was provided, along with the legal history regarding water quality, sewage and CSOs, effects of CSOs and current green infrastructure methods for dealing with CSOs. The report then compared the efforts of three cities--Portland, Oregon; Philadelphia, PA; and Chicago, IL--to improve water quality and manage CSOs and stormwater. From the examination of the efforts of these cities the author derived a list of ten recommended elements for a CSO/stormwater management plan. These recommended elements were then used to evaluate New York City's recently released sustainable stormwater management plan and its prospects for success. / text
103

Hydrological and Environmental Controls on Water Management in Semiarid Urban Areas

Resnick, Sol, DeCook, K. J. 09 1900 (has links)
Project Completion Report, OWRT Project No. B-012-ARIZ / Agreement No. 14-31-0001-3056 / Period of Operation: July 1969 to June 1972 / Acknowledgement: The work upon which this report is based was supported by funds provided by the United States Department of the Interior, Office of Water Resources Research, as authorized under the Water Resources Research Act of 1964. / Rainfall and runoff studies initiated in 1968 by the University of Arizona provide data for three small urban watersheds with different land use patterns in Tucson, Arizona. Annual precipitation of about 11 inches produces annual runoff, as measured at outflow flumes, ranging from 1.30 to 3.95 inches, produced by 15 to 23 runoff events per year. About 60 to 70 percent of the annual runoff events occur in the summer season, as does 65 to 75 percent of the annual volume of measured runoff. Water samples collected on a lumped basis show generally high concentrations of suspended sediment, bacterial loading, and dissolved organics. Initial field treatment and exploratory laboratory studies of treatment methods indicate that three days is an optimal length of time for detention storage of runoff, reducing average pollutant concentrations to 62 mg /1 of turbidity, total coliform of 70 -3200 organisms per 100 mg /1, and 7 mg /1 of chemical oxygen demand. Simple laboratory treatment with alum and polyelectrolyte yielded an 80 percent reduction in COD, 90 percent reduction in bacterial loading, and appreciable clarification of the runoff samples. Continuing research should be conducted to utilize a longer data record for improving understanding of rainfall- runoff relations; to use distributed sampling within individual watershed areas to define specific pollutant source areas; and to incorporate economic and legal questions involved in the utilization of urban runoff in an arid area.
104

Urban Flood Water Management Systems in Semi-Arid Regions: Model Extension, Design and Application: Project Completion Report

Arai, K., Ince, S., Resnick, S. D. January 1977 (has links)
Project Completion Report, OWRT Project No. A-049-ARIZ / Agreement No. 14-31-0001-4003 / Project Dates: July 1, 1973 - June 30, 1974. / Acknowledgement: The work upon which this report is based was supported by funds provided by the United States Department of the Interior, Office of Water Research and Technology, as authorized under the Water Resources Research Act of 1964. / A non-linear reservoir model is used to represent the rainfall-runoff relationships for thunderstorms on the urban watersheds of Tucson, Arizona. Two types of computer programs are developed: a calibration program to obtain a best -fit calculated hydrograph; and a verification program to generate storm hydrographs given the watershed characteristics and a hyetograph. Calibration reveals the relationship of the model parameters, namely, (f) the inflow coefficient, (a) the constant coefficient, and (TL) the time lag, to the total rainfall, drainage area, channel length, and infiltration capacity of the watershed. The average discrepancy between the predicted hydrograph and the actual hydrograph for Tucson urban watersheds is 20 -25 percent.
105

Hydrological and Environmental Controls on Water Management in Semiarid Urban Areas -- Phase II

Resnick, Sol D., DeCook, K. James, Phillips, Robert A. 03 1900 (has links)
Research Project Technical Completion Report (B-023-ARIZ) For: United States Department of the Interior, Project Dates: 1971-1973. / The work upon which this report is based was supported by federal funds provided by the United States Department of the Interior, as authorized under the Water Research and Development Act of 1978, through Agreement No. 14-31-0001-3556. / Rainfall and runoff studies initiated by the University of Arizona provide data for three small urban watersheds from 1968 and one rural watershed from 1957 to 1969. These watersheds typify various land use patterns in Tucson, Arizona. Annual precipitation of about 11 inches produces annual runoff, as measured at outflow flumes, ranging from 0.44 inches in depth for the rural watershed and 1.10 to 2.10 inches for the urban watersheds. The runoff is produced by as few as 5 runoff events per year in the rural watershed and 16 to 22 events per year for the urban watersheds. About 60 percent of the rural and 50 to 58 percent of the urban annual runoff events occur in the summer season, as does 55 to 65 percent of the annual volume of measured runoff for both. There is about a four to five-fold increase in average yearly storm runoff volume with urbanization in the Tucson area. Water samples collected on a lumped basis show generally high concentrations of suspended sediment, bacterial loading, and dissolved organics. Initial field treatment and exploratory laboratory studies of treatment methods indicate that three days is an optimal length of time for detention storage of storm runoff, reducing average pollutant concentrations to 62 mg/1 of turbidity, total coliform of 70-3,200 organisms per 100 ml, and 7 mg/1 of chemical oxygen demand. Simple laboratory treatment with alum and polyelectrolyte yielded an 80 percent reduction in COD, 90 percent reduction in bacterial loading, and appreciable clarification of the runoff samples. Multi-purpose urban storm runoff management systems can be developed to control floods while at the same time maintaining water-based linear parks along minor stream channels in semiarid regions. Multi-purpose systems are more economical than the single-purpose systems required to accomplish the same purposes. Further studies are needed to characterize the quality of storm runoff from selected urban land use areas with a view toward on-site control and disposal.
106

BIORETENTION GARDENS FOR THE REMOVAL OF NITROGEN AND PHOSPHOROUS FROM URBAN RUNOFF

Randall, Mark 12 September 2011 (has links)
Bioretention gardens are stormwater management practices that offer numerous water quantity and quality benefits. However, previous studies have reported inconsistent removal of nitrogen and phosphorous in these systems. The first phase of this research involved the construction and monitoring of ten vegetated, mesoscale, bioretention cells in a field setting to provide a comparison of the performance of five alternative designs intended to provide nutrient removal. Results indicated that concentrations of total nitrogen and total phosphorous may be reduced by up to 53 and 79%, respectively, in specially designed bioretention gardens. In the second phase of the research, a GIS-based site selection tool was used to identify areas suitable for bioretention implementation based on physical site requirements. Applying this tool to selected urban catchments demonstrated that bioretention gardens may be integrated into existing urban landscapes on a scale large enough to accommodate runoff and associated nutrient loads from small (<15mm) storms.
107

Spatial decision support system for evaluation of land use plans based upon storm water runoff impacts : a theoretical framework

Nodine, Dewayne J. January 1996 (has links)
All land uses affect storm water runoff However, different uses of the same site generate varying amounts of runoff Many communities have come to rely upon detention and/or retention basins for controlling the additional runoff resulting from land development. It is argued that this incremental approach to storm water management must be replaced with a more proactive long-term view.To achieve this, more user-friendly software capable of modeling the effect long-range land use plans have on the volume and behavior of storm water runoff is needed. This software, called a Spatial Decision Support System (SDSS), must be capable of guiding the user, who may not be an expert at runoff analysis, through the process and also capable of generating output in various formats understandable by lay persons. This study utilizes a systems analysis technique to develop a theoretical framework for the Storm Water SDSS. / Department of Urban Planning
108

GIS model for assessment of land use and urban development effects on stormwater runoff: Puhinui Catchment case study

Krpo, Ana Unknown Date (has links)
As local authorities are becoming more interested in the assessment of pollutant loads, this study offers a Geographic Information System (GIS) model for assessing nonpoint source of pollution for two scenarios: the current and ultimate stage of urbanization. The Puhinui Catchment, Manukau City, has been used as a case study in developing and testing this model. This catchment has all the attributes of a "typical" urban area and gives a good representation of the effects of land use on the receiving waters of Puhinui Stream and its estuary. Annual mass contaminant loadings were calculated by firstly assessing the physical characteristics of the Puhinui catchment (case study catchment) and secondly describing the nature of storm water quality and calculating the annual mass contaminant loadings.GIS is used to multiply the annual runoff volume by a mean pollutant concentration to acquire an average annual pollutant load. The annual runoff volume is calculated from the drainage area, runoff coefficient and annual rainfall. To calculate the total mean pollutant load, the pollutant loads for all land use types within the catchment are summed and the process is applied for each pollutant. This GIS model determines the connection of typical pollutant concentrations with land uses in the catchment and offers a characterisation of nonpoint source pollution in that catchment. This model can be used for, identifying catchment areas that contribute considerably to the pollution of waterways, determining the appropriate treatment of the storm water runoff for particular sub catchment, storm water quality improvement prioritization and cost-benefit analysis, selecting locations for water-quality monitoring stations, improvement in maintenance practices, assessment of proposed development environmental effects.
109

Modelling urban runoff : volume and pollutant concentration of the Barker Inlet Wetland Catchment /

French, Rachel. January 1999 (has links) (PDF)
Thesis (M.Eng.Sc)--University of Adelaide, Dept. of Civil and Environmental Engineering, 2000? / Bibliography :leaves 158-171. A monitoring program, funded by the South Australian government (through the former MFP Development Corporation), was established to monitor the quality and quantity of storm water entering and leaving the wetland. This study formed part of the funded program. Simple regression models were developed; and will assist in the monitoring of performance of the wetland to alleviate the pollutant load into the Barker Inlet.
110

An investigation into the treatment efficiency of a primary pond in the Barker Inlet Stormwater Wetland System, South Australia /

Murphy, Sarah Elizabeth. January 1999 (has links) (PDF)
Thesis (M.Eng.Sc.)--University of Adelaide, Dept. of Civil and Environmental Engineering, 2000? / Corrigenda pasted onto front end-paper. The CD contains Excel spreadsheets containing data collected. Bibliography: leaves 209-222.

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