Approaches to the artificial impoundment and theoretical design of sedimentation retention basin are reviewed with particular attention to best management practice(BMP) to control agriculture and surface runoff. Sedim...Approaches to the artificial impoundment and theoretical design of sedimentation retention basin are reviewed with particular attention to best management practice(BMP) to control agriculture and surface runoff. Sediments retention basins are the small version of farm pond used where a criteria of farm pond is not met. Such basin traps the pollutants and suspended solids prior to entry into streams and lakes. The study is focused with special reference to the assessment and control of non point source pollution(NPSP) from the sub basin area of Tai Lake in the Xishan County of Wuxi City of China. The author suggested two different approaches to conduct this study including theoretical design for sedimentation retention basin and computation of flow, sediment transport and deposition during the artificial impoundment of retention basin for BMP's utilization. Theoretical design will provide a useful function as a first line defense against the movement of sediments and transport of pollutants into the Tai Lake while the assessment of sediments deposition will help to make its proper use and periodic cleanup.展开更多
This study evaluated the reduction effect of non-point source pollution by applying best management practices (BMPs) to a 1.21 km^2 small agricultural watershed using a SWAT (Soil and Water Assessment Tool) model....This study evaluated the reduction effect of non-point source pollution by applying best management practices (BMPs) to a 1.21 km^2 small agricultural watershed using a SWAT (Soil and Water Assessment Tool) model. Two meter QuickBird land use data were prepared for the watershed. The SWAT was calibrated and validated using dally streamflow and monthly water quality (total phosphorus (TP), total nitrogen (TN), and suspended solids (SS)) records from 1999 to 2000 and from 2001 to 2002. The average Nash and Sutcliffe model efficiency was 0.63 for the streamflow and the coefficients of determination were 0.88, 0.72, and 0.68 for SS, TN, and TP, respectively. Four BMP scenarios viz. the application of vegetation filter strip and riparian buffer system, the regulation of Universal Soil Loss Equation P factor, and the fertilizing control amount for crops were applied and analyzed.展开更多
This paper presents a study on the use of best management practices(BMPs)for controlling nonpoint pollution in the Xikeng Reservoir watershed located in Shenzhen,China.A BMP treatment train design,including a pond,a w...This paper presents a study on the use of best management practices(BMPs)for controlling nonpoint pollution in the Xikeng Reservoir watershed located in Shenzhen,China.A BMP treatment train design,including a pond,a wetland,and a buffer strip placed in series was implemented at the reservoir location.A separate grass swale was also constructed at the site.Low impact development(LID)BMPs,namely a planter box and bioboxes,were used at the parking lot of the reservoir’s Administration Building.Samples were collected during storm events and were analyzed for total suspended solids(TSS),biochemical oxygen demand(BOD5),ammonia nitrogen(NH3-N),and total phosphorus(TP).The removal efficiencies of both BMP systems were evaluated using the Efficiency Ratio(ER)method based on the event mean concentration(EMC)data.In summary,the pond/wetland treatment train removed 70%–90%of TSS,20%–50%of BOD5,and 30%–70%of TP and NH3-N.The swale removed 50%–90%of TSS,30%–55%of BOD5,–10%–35%of NH3-N,and 25%–70%of TP.For the planter box and biobox,the ranges of removal rates were 70%–90%,20%–50%,and 30%–70%for TSS,BOD5,and ammonia and phosphorus,respectively.展开更多
Urbanization causes hydrological change and increases stormwater runoff volumes, leading to flooding, erosion, and the degradation of instream ecosystem health. Best management practices (BMPs), like detention ponds...Urbanization causes hydrological change and increases stormwater runoff volumes, leading to flooding, erosion, and the degradation of instream ecosystem health. Best management practices (BMPs), like detention ponds and infiltration trenches, have been widely used to control flood runoff events for the past decade. However, low impact development (LID) options have been proposed as an alternative approach to better mimic the natural flow regime by using decentralized designs to control stormwater runoff at the source, rather than at a centralized location in the watershed. For highly urbanized areas, LID stormwater management practices such as bioretention cells and porous pavements can be used to retrofit existing infrastructure and reduce runoff volumes and peak flows. This paper describes a modeling approach to incorporate these LID practices and the two BMPs of detention ponds and infiltration trenches in an existing hydrological model to estimate the impacts of BMPs and LID practices on the surface runoff. The modeling approach has been used in a parking lot located in Lenexa, Kansas, USA, to predict hydrological performance of BMPs and LID practices. A performance indicator system including the flow duration curve, peak flow frequency exceedance curve, and runoff coefficient have been developed in an attempt to represent impacts of BMPs and LID practices on the entire spectrum of the runoff regime. Results demonstrate that use of these BMPs and LID practices leads to significant stormwater control for small rainfall events and less control for flood events.展开更多
This paper presents an approach based on field data to model the spatial distribution of the site productivity index (SPI) of the diverse forest types in Jalisco, Mexico and the response in SPI to site and cli-matic...This paper presents an approach based on field data to model the spatial distribution of the site productivity index (SPI) of the diverse forest types in Jalisco, Mexico and the response in SPI to site and cli-matic conditions. A linear regression model was constructed to test the hypothesis that site and climate variables can be used to predict the SPI of the major forest types in Jalisco. SPI varied significantly with topog-raphy (elevation, aspect and slope), soil attributes (pH, sand and silt), climate (temperature and precipitation zones) and forest type. The most important variable in the model was forest type, which accounted for 35% of the variability in SPI. Temperature and precipitation accounted for 8 to 9% of the variability in SPI while the soil attributes accounted for less than 4% of the variability observed in SPI. No significant differences were detected between the observed and predicted SPI for the individual forest types. The linear regression model was used to develop maps of the spatial variability in predicted SPI for the individual forest types in the state. The spatial site productivity models developed in this study provides a basis for understanding the complex relationship that exists between forest productivity and site and climatic conditions in the state. Findings of this study will assist resource managers in making cost-effective decisions about the management of individual forest types in the state of Jalisco, Mexico.展开更多
The feasibility of rooftop rainwater harvesting (RRWH) as an alternative source of water to meet the outdoor water demand in nine states of the U.S. was evaluated using a system dynamics model developed in Systems T...The feasibility of rooftop rainwater harvesting (RRWH) as an alternative source of water to meet the outdoor water demand in nine states of the U.S. was evaluated using a system dynamics model developed in Systems Thinking, Experimental Learning Laboratory with Animation. The state of Arizona was selected to evaluate the effects of the selected model parameters on the efficacy of RRWH since among the nine states the arid region of Arizona showed the least potential of meeting the outdoor water demand with rain harvested water. The analyses were conducted on a monthly basis across a 10-year projected period from 2015 to 2024. The results showed that RRWH as a potential source of water was highly sensitive to certain model parameters such as the outdoor water demand, the use of desert landscaping, and the percentage of existing houses with RRWH. A significant difference (as high as 37.5%) in rainwater potential was observed between the projected wet and dry climate conditions in Arizona. The analysis of the dynamics of the storage tanks suggested that a 1.0-2.0 m3 rainwater barrel, on an average, can store approximately 80% of the monthly rainwater generated from the rooftops in Arizona, even across the high seasonal variation. This interactive model can be used as a quick estimator of the amount of water that could be generated, stored, and utilized through RRWH systems in the U.S. under different climate conditions. The findings of such comprehensive analyses may help regional policymakers, especially in arid regions, to develop a sustainable water management infrastructure.展开更多
China is at present experiencing a very rapid urbanization process, which has brought a number of adverse impacts upon the water environment. In particular, urban runoff quantity and quality control have emerged as on...China is at present experiencing a very rapid urbanization process, which has brought a number of adverse impacts upon the water environment. In particular, urban runoff quantity and quality control have emerged as one of the key concerns for municipal officials. One of the strategies being considered is the use of a Low Impact Development type of Best Management Practices (LID BMPs) for urban storm water runoff quantity and quality control. In this paper, the situation surrounding urban runoff control in China is reviewed first. Then the conventional strategy and technologies for the construction and management of urban drainage systems are discussed, while exploring their inherent dilemmas. The LID BMPs are then introduced to control urban runoff in the context of urban sustainable water systems. After the comprehensive analysis of the various LID BMPs, the advances in LID BMPs research and practice for urban runoff control in China are investigated and summarized. At last, the difficulties of implementing LID BMPs in China are discussed, and a direction for the future is proposed.展开更多
Soil and water conservation practices have been extensively used in effective watershed management.The impact of each conservation practice is site specific and dependent on the implementation site in the watershed.In...Soil and water conservation practices have been extensively used in effective watershed management.The impact of each conservation practice is site specific and dependent on the implementation site in the watershed.In order to select cost effective placement of conservation practices with high impact,a large number of spatial combinations is needed to be compared.In this study,an optimization model framework is presented to find cost effective solutions for sediment yield and runoff control in the Fariman dam watershed in the Northeast of Iran.This was accomplished by integrating soil and water assessment tool(SWAT)for simulation of watershed hydrology and multi objective genetic algorithm(NSGA-II)for spatial optimization of soil and water conservation practices.The optimized solutions provided a trade-off between the two objective functions.The final Pareto-optimal shows that the impact of soil and water conservation practices on sediment yield is more than stream flow.The trade-offs between the objective functions show that the implementation of the median cost can lead to a significant decrease of 22.1%in the amount of sediment yield,and 10%in stream flow.Also,percent change achieved through median cost is very close to percent reduction with the highest cost.Results of low cost solution show that the vegetative practices are a suitable economic scenario for soil and water conservation.The introduced framework can be adapted as a suitable tool for selecting cost effective conservation practices in different regions.展开更多
Prince George’s County,Maryland,in the Washington D.C.metropolitan area has developed a best management practice decision support system(BMPDSS)to support analysis and decision making for stormwater management planni...Prince George’s County,Maryland,in the Washington D.C.metropolitan area has developed a best management practice decision support system(BMPDSS)to support analysis and decision making for stormwater management planning and design at both the site scale and the watershed levels.This paper presents a detailed description of the BMPDSS.A case study that demonstrates the application of the system is also included.The case study involves a Green Highway project located in a highly urbanized area within the Anacostia River watershed of the county.Several best management practices(BMP)such as bioretention,filter vegetative swale,porous paving,and landscape infiltration are proposed for reducing highway runoff and improving water quality.The BMPDSS is used to identify and evaluate various alternatives to determine the most costeffective types and combinations of BMPs that minimize the highway runoff pollution.展开更多
The Korea government has put in a lot of effort to construct sanitation facilities for controlling non-point source pollution. The first flush phenomenon is a prime example of such pollution. However, to date, several...The Korea government has put in a lot of effort to construct sanitation facilities for controlling non-point source pollution. The first flush phenomenon is a prime example of such pollution. However, to date, several serious problems have arisen in the operation and treatment effectiveness of these facilities due to unsuitable design flow volumes and pollution loads. It is difficult to assess the optimal flow volume and pollution mass when considering both monetary and temporal limitations. The objective of this article was to characterize the discharge of storm runoff pollution from urban catchments in Korea and to estimate the probability of mass first flush (MFFn) using the storm water management model and probability density functions. As a result of the review of gauged storms for the representative using probability density function with rainfall volumes during the last two years, all the gauged storms were found to be valid representative precipitation. Both the observed MFFn and probability MFFn in BE-1 denoted similarly large magnitudes of first flush with roughly 40% of the total pollution mass contained in the first 20% of the runoff. In the case of BE-2, however, there were significant difference between the observed MFFn and probability MFFn.展开更多
A structued stormwater infiltration system was developed and constructed at a university campus and monitoring of storm events was performed during a one- year operation period. The flow and pollutant mass balances we...A structued stormwater infiltration system was developed and constructed at a university campus and monitoring of storm events was performed during a one- year operation period. The flow and pollutant mass balances were analyzed and the overall efficiency of the system was assessed. While significant positive correla- tions were observed among rainfall, runoff and discharge volume (R2= 0.93-0.99; p 〈 0.05), there was no sig- nificant correlations existed between rainfall, runoff, discharge volume and pollutant load. The system was more effective in reducing the runoff volume by more than 50% for small storm events but the difference between the runoff and discharge volume was significant even with rainfall greater than 10ram. Results showed that the pollutant reduction rates were higher compared to the runoff volume reduction. Average pollutant reduction rates were in the range of 72% to 90% with coefficient of variation between 0.10 and 0.46. Comparable with runoff reduction, the system was more effective in reducing the pollutant load for small storm events, in the range of 80% to 100% for rainfall between 0 and 10mm; while 65% to 80% for rainfall between l0 and 20mm. Among the pollutant parameters, particulate matters was highly reduced by the system achieving only a maximum of 25% discharge load even after the entire runoff was completely discharged. The findings have proven the capability of the system as a tool in stormwater manage- ment achieving both flow reduction and water quality improvement.展开更多
文摘Approaches to the artificial impoundment and theoretical design of sedimentation retention basin are reviewed with particular attention to best management practice(BMP) to control agriculture and surface runoff. Sediments retention basins are the small version of farm pond used where a criteria of farm pond is not met. Such basin traps the pollutants and suspended solids prior to entry into streams and lakes. The study is focused with special reference to the assessment and control of non point source pollution(NPSP) from the sub basin area of Tai Lake in the Xishan County of Wuxi City of China. The author suggested two different approaches to conduct this study including theoretical design for sedimentation retention basin and computation of flow, sediment transport and deposition during the artificial impoundment of retention basin for BMP's utilization. Theoretical design will provide a useful function as a first line defense against the movement of sediments and transport of pollutants into the Tai Lake while the assessment of sediments deposition will help to make its proper use and periodic cleanup.
基金supported by a grant (code # 2-2-3) from Sustainable Water Resources Research Center of 21st Century Frontier Research Programthe Development of The Third Korea Multe-Purpose Satellite funded by Ministry of Education Science
文摘This study evaluated the reduction effect of non-point source pollution by applying best management practices (BMPs) to a 1.21 km^2 small agricultural watershed using a SWAT (Soil and Water Assessment Tool) model. Two meter QuickBird land use data were prepared for the watershed. The SWAT was calibrated and validated using dally streamflow and monthly water quality (total phosphorus (TP), total nitrogen (TN), and suspended solids (SS)) records from 1999 to 2000 and from 2001 to 2002. The average Nash and Sutcliffe model efficiency was 0.63 for the streamflow and the coefficients of determination were 0.88, 0.72, and 0.68 for SS, TN, and TP, respectively. Four BMP scenarios viz. the application of vegetation filter strip and riparian buffer system, the regulation of Universal Soil Loss Equation P factor, and the fertilizing control amount for crops were applied and analyzed.
基金the US Environmental Protection Agency,National Risk Management Research Laboratory,and Urban Watershed Management Branch(H00562)。
文摘This paper presents a study on the use of best management practices(BMPs)for controlling nonpoint pollution in the Xikeng Reservoir watershed located in Shenzhen,China.A BMP treatment train design,including a pond,a wetland,and a buffer strip placed in series was implemented at the reservoir location.A separate grass swale was also constructed at the site.Low impact development(LID)BMPs,namely a planter box and bioboxes,were used at the parking lot of the reservoir’s Administration Building.Samples were collected during storm events and were analyzed for total suspended solids(TSS),biochemical oxygen demand(BOD5),ammonia nitrogen(NH3-N),and total phosphorus(TP).The removal efficiencies of both BMP systems were evaluated using the Efficiency Ratio(ER)method based on the event mean concentration(EMC)data.In summary,the pond/wetland treatment train removed 70%–90%of TSS,20%–50%of BOD5,and 30%–70%of TP and NH3-N.The swale removed 50%–90%of TSS,30%–55%of BOD5,–10%–35%of NH3-N,and 25%–70%of TP.For the planter box and biobox,the ranges of removal rates were 70%–90%,20%–50%,and 30%–70%for TSS,BOD5,and ammonia and phosphorus,respectively.
基金supported by the National Natural Science Foundation of China(Grants No.51279064 and 51209090)
文摘Urbanization causes hydrological change and increases stormwater runoff volumes, leading to flooding, erosion, and the degradation of instream ecosystem health. Best management practices (BMPs), like detention ponds and infiltration trenches, have been widely used to control flood runoff events for the past decade. However, low impact development (LID) options have been proposed as an alternative approach to better mimic the natural flow regime by using decentralized designs to control stormwater runoff at the source, rather than at a centralized location in the watershed. For highly urbanized areas, LID stormwater management practices such as bioretention cells and porous pavements can be used to retrofit existing infrastructure and reduce runoff volumes and peak flows. This paper describes a modeling approach to incorporate these LID practices and the two BMPs of detention ponds and infiltration trenches in an existing hydrological model to estimate the impacts of BMPs and LID practices on the surface runoff. The modeling approach has been used in a parking lot located in Lenexa, Kansas, USA, to predict hydrological performance of BMPs and LID practices. A performance indicator system including the flow duration curve, peak flow frequency exceedance curve, and runoff coefficient have been developed in an attempt to represent impacts of BMPs and LID practices on the entire spectrum of the runoff regime. Results demonstrate that use of these BMPs and LID practices leads to significant stormwater control for small rainfall events and less control for flood events.
文摘This paper presents an approach based on field data to model the spatial distribution of the site productivity index (SPI) of the diverse forest types in Jalisco, Mexico and the response in SPI to site and cli-matic conditions. A linear regression model was constructed to test the hypothesis that site and climate variables can be used to predict the SPI of the major forest types in Jalisco. SPI varied significantly with topog-raphy (elevation, aspect and slope), soil attributes (pH, sand and silt), climate (temperature and precipitation zones) and forest type. The most important variable in the model was forest type, which accounted for 35% of the variability in SPI. Temperature and precipitation accounted for 8 to 9% of the variability in SPI while the soil attributes accounted for less than 4% of the variability observed in SPI. No significant differences were detected between the observed and predicted SPI for the individual forest types. The linear regression model was used to develop maps of the spatial variability in predicted SPI for the individual forest types in the state. The spatial site productivity models developed in this study provides a basis for understanding the complex relationship that exists between forest productivity and site and climatic conditions in the state. Findings of this study will assist resource managers in making cost-effective decisions about the management of individual forest types in the state of Jalisco, Mexico.
文摘The feasibility of rooftop rainwater harvesting (RRWH) as an alternative source of water to meet the outdoor water demand in nine states of the U.S. was evaluated using a system dynamics model developed in Systems Thinking, Experimental Learning Laboratory with Animation. The state of Arizona was selected to evaluate the effects of the selected model parameters on the efficacy of RRWH since among the nine states the arid region of Arizona showed the least potential of meeting the outdoor water demand with rain harvested water. The analyses were conducted on a monthly basis across a 10-year projected period from 2015 to 2024. The results showed that RRWH as a potential source of water was highly sensitive to certain model parameters such as the outdoor water demand, the use of desert landscaping, and the percentage of existing houses with RRWH. A significant difference (as high as 37.5%) in rainwater potential was observed between the projected wet and dry climate conditions in Arizona. The analysis of the dynamics of the storage tanks suggested that a 1.0-2.0 m3 rainwater barrel, on an average, can store approximately 80% of the monthly rainwater generated from the rooftops in Arizona, even across the high seasonal variation. This interactive model can be used as a quick estimator of the amount of water that could be generated, stored, and utilized through RRWH systems in the U.S. under different climate conditions. The findings of such comprehensive analyses may help regional policymakers, especially in arid regions, to develop a sustainable water management infrastructure.
文摘China is at present experiencing a very rapid urbanization process, which has brought a number of adverse impacts upon the water environment. In particular, urban runoff quantity and quality control have emerged as one of the key concerns for municipal officials. One of the strategies being considered is the use of a Low Impact Development type of Best Management Practices (LID BMPs) for urban storm water runoff quantity and quality control. In this paper, the situation surrounding urban runoff control in China is reviewed first. Then the conventional strategy and technologies for the construction and management of urban drainage systems are discussed, while exploring their inherent dilemmas. The LID BMPs are then introduced to control urban runoff in the context of urban sustainable water systems. After the comprehensive analysis of the various LID BMPs, the advances in LID BMPs research and practice for urban runoff control in China are investigated and summarized. At last, the difficulties of implementing LID BMPs in China are discussed, and a direction for the future is proposed.
文摘Soil and water conservation practices have been extensively used in effective watershed management.The impact of each conservation practice is site specific and dependent on the implementation site in the watershed.In order to select cost effective placement of conservation practices with high impact,a large number of spatial combinations is needed to be compared.In this study,an optimization model framework is presented to find cost effective solutions for sediment yield and runoff control in the Fariman dam watershed in the Northeast of Iran.This was accomplished by integrating soil and water assessment tool(SWAT)for simulation of watershed hydrology and multi objective genetic algorithm(NSGA-II)for spatial optimization of soil and water conservation practices.The optimized solutions provided a trade-off between the two objective functions.The final Pareto-optimal shows that the impact of soil and water conservation practices on sediment yield is more than stream flow.The trade-offs between the objective functions show that the implementation of the median cost can lead to a significant decrease of 22.1%in the amount of sediment yield,and 10%in stream flow.Also,percent change achieved through median cost is very close to percent reduction with the highest cost.Results of low cost solution show that the vegetative practices are a suitable economic scenario for soil and water conservation.The introduced framework can be adapted as a suitable tool for selecting cost effective conservation practices in different regions.
文摘Prince George’s County,Maryland,in the Washington D.C.metropolitan area has developed a best management practice decision support system(BMPDSS)to support analysis and decision making for stormwater management planning and design at both the site scale and the watershed levels.This paper presents a detailed description of the BMPDSS.A case study that demonstrates the application of the system is also included.The case study involves a Green Highway project located in a highly urbanized area within the Anacostia River watershed of the county.Several best management practices(BMP)such as bioretention,filter vegetative swale,porous paving,and landscape infiltration are proposed for reducing highway runoff and improving water quality.The BMPDSS is used to identify and evaluate various alternatives to determine the most costeffective types and combinations of BMPs that minimize the highway runoff pollution.
文摘The Korea government has put in a lot of effort to construct sanitation facilities for controlling non-point source pollution. The first flush phenomenon is a prime example of such pollution. However, to date, several serious problems have arisen in the operation and treatment effectiveness of these facilities due to unsuitable design flow volumes and pollution loads. It is difficult to assess the optimal flow volume and pollution mass when considering both monetary and temporal limitations. The objective of this article was to characterize the discharge of storm runoff pollution from urban catchments in Korea and to estimate the probability of mass first flush (MFFn) using the storm water management model and probability density functions. As a result of the review of gauged storms for the representative using probability density function with rainfall volumes during the last two years, all the gauged storms were found to be valid representative precipitation. Both the observed MFFn and probability MFFn in BE-1 denoted similarly large magnitudes of first flush with roughly 40% of the total pollution mass contained in the first 20% of the runoff. In the case of BE-2, however, there were significant difference between the observed MFFn and probability MFFn.
文摘A structued stormwater infiltration system was developed and constructed at a university campus and monitoring of storm events was performed during a one- year operation period. The flow and pollutant mass balances were analyzed and the overall efficiency of the system was assessed. While significant positive correla- tions were observed among rainfall, runoff and discharge volume (R2= 0.93-0.99; p 〈 0.05), there was no sig- nificant correlations existed between rainfall, runoff, discharge volume and pollutant load. The system was more effective in reducing the runoff volume by more than 50% for small storm events but the difference between the runoff and discharge volume was significant even with rainfall greater than 10ram. Results showed that the pollutant reduction rates were higher compared to the runoff volume reduction. Average pollutant reduction rates were in the range of 72% to 90% with coefficient of variation between 0.10 and 0.46. Comparable with runoff reduction, the system was more effective in reducing the pollutant load for small storm events, in the range of 80% to 100% for rainfall between 0 and 10mm; while 65% to 80% for rainfall between l0 and 20mm. Among the pollutant parameters, particulate matters was highly reduced by the system achieving only a maximum of 25% discharge load even after the entire runoff was completely discharged. The findings have proven the capability of the system as a tool in stormwater manage- ment achieving both flow reduction and water quality improvement.