Flood control detention basins （DBs） can act as water quality control structures or best management practices （BMPs）. A key pollutant that DBs serve to settle out is particulate phosphorus, which adsorbs onto sedi...Flood control detention basins （DBs） can act as water quality control structures or best management practices （BMPs）. A key pollutant that DBs serve to settle out is particulate phosphorus, which adsorbs onto sediment. This study examines the sediment phosphorus concentration and its relationship with the particle size of sediment microcosms from pre- and post-rain event samples obtained from six DBs located in Clark County, Nevada. DBs were allotted a land use classification to determine if there was a correlation between the sediment phosphorus concentration and surrounding land use. The curve number method was used to calculate the runoff and subsequent phosphorus carried into the DB by the runoff. Our data show sediment phosphorus concentrations to he highest in soils from undeveloped areas. Runoff amount also plays a substantial role in determining the amount of phosphorus brought into the DB by sediment. This research has implications for improvement of water quality in arid regions.展开更多
Emission trading is one of the most effectivealternatives to controlling water pollution.Water environmentalfunctional zone(WEFZ)is used to determine thewater quality standard and identify the zone boundary foreach ri...Emission trading is one of the most effectivealternatives to controlling water pollution.Water environmentalfunctional zone(WEFZ)is used to determine thewater quality standard and identify the zone boundary foreach river or reach.In this study,a new emission tradingscheme was addressed based on WEFZ,accounting forboth the temporal dimension and water quality control.Atemporal factor of emission trading was proposed based onvariations in the environmental capacity within a year bydividing the year into three periods,including high,normal,and low periods of environmental capacity.Duringeach period,emission trading was implemented exclusively.A water quality-control scheme was suggestedbased on the water quality requirement in the waterfunctional zone,in which the water quality at thedownstream boundary of the zone was required to meetthe water standard following auto-purification in thestream.Two methods of calculating water quality controlare addressed for point-source pollution and non-pointsourcepollution.The calculated temporal dimension andwater quality control were located in Dongxi River of theDaning Watershed in the Three Gorges Watershed.Thehigh period was during June,July,and August,the normalperiod was during April,May,September,and October,and the low period was during January,February,March,November,and December.The results from the waterquality calculation demonstrated that the discharge ofpoint-source and non-point-source pollutions led to anexcess of common contaminants at the downstreamboundary of WEFZ.The temporal and spatial factorsabove should be incorporated into the emission tradingscheme based on WEFZ.展开更多
基金supported by the Urban Flood Demonstration Program of the United States Army Corps of Engineers(Grant No.W912HZ-08-2-0021)
文摘Flood control detention basins （DBs） can act as water quality control structures or best management practices （BMPs）. A key pollutant that DBs serve to settle out is particulate phosphorus, which adsorbs onto sediment. This study examines the sediment phosphorus concentration and its relationship with the particle size of sediment microcosms from pre- and post-rain event samples obtained from six DBs located in Clark County, Nevada. DBs were allotted a land use classification to determine if there was a correlation between the sediment phosphorus concentration and surrounding land use. The curve number method was used to calculate the runoff and subsequent phosphorus carried into the DB by the runoff. Our data show sediment phosphorus concentrations to he highest in soils from undeveloped areas. Runoff amount also plays a substantial role in determining the amount of phosphorus brought into the DB by sediment. This research has implications for improvement of water quality in arid regions.
基金This research was supported by the Nonprofit Environmental Protection Specific Project of China(No.200709024)the National Natural Science Foundation of China(Grant No.40771193).
文摘Emission trading is one of the most effectivealternatives to controlling water pollution.Water environmentalfunctional zone(WEFZ)is used to determine thewater quality standard and identify the zone boundary foreach river or reach.In this study,a new emission tradingscheme was addressed based on WEFZ,accounting forboth the temporal dimension and water quality control.Atemporal factor of emission trading was proposed based onvariations in the environmental capacity within a year bydividing the year into three periods,including high,normal,and low periods of environmental capacity.Duringeach period,emission trading was implemented exclusively.A water quality-control scheme was suggestedbased on the water quality requirement in the waterfunctional zone,in which the water quality at thedownstream boundary of the zone was required to meetthe water standard following auto-purification in thestream.Two methods of calculating water quality controlare addressed for point-source pollution and non-pointsourcepollution.The calculated temporal dimension andwater quality control were located in Dongxi River of theDaning Watershed in the Three Gorges Watershed.Thehigh period was during June,July,and August,the normalperiod was during April,May,September,and October,and the low period was during January,February,March,November,and December.The results from the waterquality calculation demonstrated that the discharge ofpoint-source and non-point-source pollutions led to anexcess of common contaminants at the downstreamboundary of WEFZ.The temporal and spatial factorsabove should be incorporated into the emission tradingscheme based on WEFZ.
