China started a Sponge City program to offset the adverse impacts of urban developments and to tackle many water-related problems.By emphasizing stormwater management practices with“natural solutions”,many positive ...China started a Sponge City program to offset the adverse impacts of urban developments and to tackle many water-related problems.By emphasizing stormwater management practices with“natural solutions”,many positive results have been achieved.The operation and maintenance(O&M)of Sponge City to support long-term success gained considerable focus.China is facing challenges many developed countries have encountered,as well as unique ones due to specific social,economic,and environmental conditions.This study identified and discussed Sponge City O&M challenges:(1)scheduling challenges,(2)technical challenges,(3)in short of local regulation/ordnance,(4)inadequate O&M assessment standard,(5)underprovided training,(6)PPP related concerns,(7)inter-agency coordination needs,(8)ownership and responsible party issues,(9)substandard documentation,and(10)funding and financial concerns.Selected cases and progress in pilot cities are introduced in the discussions.展开更多
Stimulated by the recent USEPA＇s green stormwater infrastructure （GSI） guidance and policies, GS1 systems have been widely implemented in the municipal area to control the combined sewer overflows （CSOs）, also kn...Stimulated by the recent USEPA＇s green stormwater infrastructure （GSI） guidance and policies, GS1 systems have been widely implemented in the municipal area to control the combined sewer overflows （CSOs）, also known as low impact development （LID） approaches. To quantitatively evaluate the performance of GSI systems on CSO and urban flooding control, USEPA-Stormwater Management Model （SWMM） model was adopted in this study to simulate the behaviors of GSI systems in a well- developed urban drainage area, PSW45, under different circumstances. The impact of different percentages of stormwater runoff transported from impervious surfaces to the GSI systems on CSO and urban flooding control has also been investigated. Results show that with current buildup, GSI systems in PSW45 have the best performance for low intensity and short duration events on both volume and peak flow reductions, and have the worst pertbrmance tor high intensity and long durataon events. Since the low intensity and short duration events are dominant from a long-term perspective, utilizing GSI systems is considered as an effective measure of CSO control to meet the long-term controlstrategy for PSW45 watershed. However, GSI systems are not suitable for the flooding control purpose in PSW45 due to the high occurrence possibility of urban flooding during or after high intensity events where GSI systems have relatively poor performance no matter for a short or long duration event,展开更多
Runoff coefficient is an important parameter for the decision support of urban stormwater management. However, factors like comprehensive land-use type, variable spatial elevation, dynamic rainfall and groundwater ele...Runoff coefficient is an important parameter for the decision support of urban stormwater management. However, factors like comprehensive land-use type, variable spatial elevation, dynamic rainfall and groundwater elevation, make the direct estimation of runoff coefficient difficult. This paper presented a novel method to estimate the urban runoff coefficient using the inverse method, where observed time-series catchment outfall flow volume was employed as input for the water balance model and runoff coefficients of different catchments were treated as unknown parameters. A developed constrained minimization objective function was combined to solve the model and minimized error between observed and modeled outfall flow is satisfactory for the presenting of a set of runoff coefficients. Estimated runoff coefficients for the urban catchments in Shanghai downtown area demonstrated that practice of low impact design could play an important role in reducing the urban runoff.展开更多
基金supported by the National Key Research and Development Program of China under Grant 2016YFC0701001.
文摘China started a Sponge City program to offset the adverse impacts of urban developments and to tackle many water-related problems.By emphasizing stormwater management practices with“natural solutions”,many positive results have been achieved.The operation and maintenance(O&M)of Sponge City to support long-term success gained considerable focus.China is facing challenges many developed countries have encountered,as well as unique ones due to specific social,economic,and environmental conditions.This study identified and discussed Sponge City O&M challenges:(1)scheduling challenges,(2)technical challenges,(3)in short of local regulation/ordnance,(4)inadequate O&M assessment standard,(5)underprovided training,(6)PPP related concerns,(7)inter-agency coordination needs,(8)ownership and responsible party issues,(9)substandard documentation,and(10)funding and financial concerns.Selected cases and progress in pilot cities are introduced in the discussions.
文摘Stimulated by the recent USEPA＇s green stormwater infrastructure （GSI） guidance and policies, GS1 systems have been widely implemented in the municipal area to control the combined sewer overflows （CSOs）, also known as low impact development （LID） approaches. To quantitatively evaluate the performance of GSI systems on CSO and urban flooding control, USEPA-Stormwater Management Model （SWMM） model was adopted in this study to simulate the behaviors of GSI systems in a well- developed urban drainage area, PSW45, under different circumstances. The impact of different percentages of stormwater runoff transported from impervious surfaces to the GSI systems on CSO and urban flooding control has also been investigated. Results show that with current buildup, GSI systems in PSW45 have the best performance for low intensity and short duration events on both volume and peak flow reductions, and have the worst pertbrmance tor high intensity and long durataon events. Since the low intensity and short duration events are dominant from a long-term perspective, utilizing GSI systems is considered as an effective measure of CSO control to meet the long-term controlstrategy for PSW45 watershed. However, GSI systems are not suitable for the flooding control purpose in PSW45 due to the high occurrence possibility of urban flooding during or after high intensity events where GSI systems have relatively poor performance no matter for a short or long duration event,
基金Project supported by the China’s Major Science and Technology Program on Water Bodies Pollution Control and Treatment(Grant No.2013ZX07304-002)
文摘Runoff coefficient is an important parameter for the decision support of urban stormwater management. However, factors like comprehensive land-use type, variable spatial elevation, dynamic rainfall and groundwater elevation, make the direct estimation of runoff coefficient difficult. This paper presented a novel method to estimate the urban runoff coefficient using the inverse method, where observed time-series catchment outfall flow volume was employed as input for the water balance model and runoff coefficients of different catchments were treated as unknown parameters. A developed constrained minimization objective function was combined to solve the model and minimized error between observed and modeled outfall flow is satisfactory for the presenting of a set of runoff coefficients. Estimated runoff coefficients for the urban catchments in Shanghai downtown area demonstrated that practice of low impact design could play an important role in reducing the urban runoff.
