[Objective] This study aimed to study on influence of rainfall runoff on non-point pollution and to reduce the pollution through control of the contamination produced from rainfall runoff. [Method] In order to explore...[Objective] This study aimed to study on influence of rainfall runoff on non-point pollution and to reduce the pollution through control of the contamination produced from rainfall runoff. [Method] In order to explore effective methods to decrease non-point pollution, we conducted analysis on hydrological process of rainfall runoff, interaction mechanism between the process and non-point pollutants, the influence on non-point pollution and hydrological model application in the research. [Result] It was proved that rainfall runoff was the main factor of non-point pollution. Control from source strengthened clearing and controlling of non-point pollutants on the ground. Growing plants in slope effectively reduced the scour and erosion of rainfall runoff on soil. The study became simple thanks for the hydrological process. [Conclusion] The research indicated that non-point pollution would be effectively reduced through control of rainfall runoff.展开更多
Rainwater and run-off from three kinds of impervious surface in the Shanghai urban area,China were sampled.Polycyclic aromatic hydrocarbons(PAHs) were measured in the samples,and their sources were assessed.The mean s...Rainwater and run-off from three kinds of impervious surface in the Shanghai urban area,China were sampled.Polycyclic aromatic hydrocarbons(PAHs) were measured in the samples,and their sources were assessed.The mean sum of the 16 PAH concentrations measured in rainwater and run-offs from ceramic tiles,asphalt roofs,and asphalt roads were 873,1404,1743,and 4023 ng/L,respectively.The PAH concentrations found in this study were moderate compared to PAH concentrations found in run-offs in other studies.The main PAH components in the rainwater,roof run-off,and asphalt road run-off samples were 3-ring PAHs,3–4-ring PAHs,and 4–6-ring PAHs,respectively.Source apportionment results indicated that combustion(47.4%–55.5%) and vehicular emissions(30.5%–33.0%) were the major contributors to PAHs in roof run-off.Vehicular emissions were the most significant contributors to asphalt road run-off(47.2%),followed by combustion(23.5%),and petroleum(16.3%).Vehicular emissions and coal and natural gas combustion are therefore the most significant sources of PAHs in run-off from impervious surfaces in the Shanghai urban area.展开更多
Under the condition of different precipitation intensities, different gradients, different land-use types and different vegetation coverage, the soil erosion and transference of element (or pollutant) are studied by s...Under the condition of different precipitation intensities, different gradients, different land-use types and different vegetation coverage, the soil erosion and transference of element (or pollutant) are studied by simulating and analyzing the surface run-off of experimental plots in the catchment area of Songhua Lake, with an area of about 43 370.8km2. And the influencing factors that produce the spatial difference are analyzed and assessed. It is put forward that the irrational land utilization is the reason of soil erosion and pollutant run-off. The gradient of farmland, the growing season of vegetation and the vegetation coverage are chiefly restricting factors that lead to the soil erosion and pollutant run-off. This study can provide the fundamental data for comprehensive planning and harnessing of the non-point source pollution in the valley.展开更多
Run-off-road crashes in the United States have become a major cause of serious injuries and fatalities. A significant portion of run-off-road crashes are single vehicle crashes that occur due to collisions with fixed ...Run-off-road crashes in the United States have become a major cause of serious injuries and fatalities. A significant portion of run-off-road crashes are single vehicle crashes that occur due to collisions with fixed objects and overturning. These crashes typically tend to be more severe than other types of crashes. Single vehicle run-off-road crashes that occurred between 2004 and 2008 were extracted from Kansas Accident Reporting System (KARS) database to identify the important factors that affected their severity. Different driver, vehicle, road, crash, and environment related factors that influence crash severity are identified by using binary logit models. Three models were developed to take different levels of crash severity as the response variables. The first model taking fatal or incapacitating crashes as the response variable seems to better fit the data than the other two developed models. The variables that were found to increase the probability of run-off-road crash severity are driver related factors such as driver ejection, being an older driver, alcohol involvement, license state, driver being at fault, medical condition of the driver;road related factors such as speed, asphalt road surface, dry road condition;time related factors such as crashes occurring between 6 pm and midnight;environment related factors such as daylight;vehicle related factors such as being an SUV, motorcycles, vehicle getting destroyed or disabled, vehicle maneuver being straight or passing;and fixed object types such as trees and ditches.展开更多
Aims The Miyun Reservoir is the most important drinking water source for Beijing—the capital of China with a population of more than 16 million.Since the 1980s,the inflow to the reservoir has been decreasing,which se...Aims The Miyun Reservoir is the most important drinking water source for Beijing—the capital of China with a population of more than 16 million.Since the 1980s,the inflow to the reservoir has been decreasing,which seriously threatens the security of water use in Beijing.Our goal was to analyze the impact of land use and cover change(LUCC)on run-off yield in the upstream of the Miyun Reservoir.Methods In this study,the Soil andWater Assessment Tool(SWAT)was used to simulate the impacts of LUCC on the run-off yield in the Bai River catchment—upstream of the Miyun Reservoir basin in northern China.The investigation was conducted using two 6-year historical streamflow records:from 1986 to 1991 and from 2000 to 2005.A split sample procedure was used for model calibration and validation.The data from 1986 to 1988 and from 2000 to 2002 were used for calibration,while those from 1989 to 1991 and from 2003 to 2005 for validation.The SWAT calibration was based on monthly measured discharge at Zhangjiafen station at the catchment outlet from Bai River catchment.Additionally,the influence of LUCC on the surface run-off was distinguished from that of climate change on the surface runoff through SWAT scenarios modeling,the twoway analysis of variance(ANOVA),and the rainfall–run-off double-mass analysis in the Bai River catchment.Important Findings We found that the SWAT model could be used successfully to accurately simulate run-off yield and different LUCC patterns affecting water quantity in this catchment.During calibraion for the two periods the simulated monthly run-off satisfactorily matched the observed values,with the Nash–Sutcliffe coefficient>0.9 and 0.7 and a coefficient of determination of 0.9 and 0.65 at the outlet station(Zhangjiafen station),while during validation for the two periods the obtained values were 0.85,0.65 and 0.9,0.65,respectively.During the period of 1986–91,both the SWAT scenarios modeling and the analysis of the two-way ANOVA method showed that LUCC and climate change had some impact on run-off,and the impact of climate change was more significant than that of LUCC.Compared with the period during 1986–91,the run-off yield in the period during 2000–05 significantly decreased.The obtained results from the rainfall–run-off double-mass analysis indicate that since 1998 LUCC has had an increasing influence on the run-off,while the response of the run-off to rainfall has been decreasing.Since 1998,the LUCC has been a major driving force for run-off change in Bai River catchment.展开更多
基金Supported by Major Special Fund of National Technology Program of China(2008ZX07421-002,2008ZX07421-004)the National High Technology Research and Development Program of China(2008AA06A412)Project Studied and Developed by Ministry of Housing and Urban-Rural Construction(2009-K7-4)~~
文摘[Objective] This study aimed to study on influence of rainfall runoff on non-point pollution and to reduce the pollution through control of the contamination produced from rainfall runoff. [Method] In order to explore effective methods to decrease non-point pollution, we conducted analysis on hydrological process of rainfall runoff, interaction mechanism between the process and non-point pollutants, the influence on non-point pollution and hydrological model application in the research. [Result] It was proved that rainfall runoff was the main factor of non-point pollution. Control from source strengthened clearing and controlling of non-point pollutants on the ground. Growing plants in slope effectively reduced the scour and erosion of rainfall runoff on soil. The study became simple thanks for the hydrological process. [Conclusion] The research indicated that non-point pollution would be effectively reduced through control of rainfall runoff.
基金supported by the National Key Technology R&D Program of China(No.2010BAK69B16-1)the Shanghai Commission of Science and Technology(No.10dz1200402),China
文摘Rainwater and run-off from three kinds of impervious surface in the Shanghai urban area,China were sampled.Polycyclic aromatic hydrocarbons(PAHs) were measured in the samples,and their sources were assessed.The mean sum of the 16 PAH concentrations measured in rainwater and run-offs from ceramic tiles,asphalt roofs,and asphalt roads were 873,1404,1743,and 4023 ng/L,respectively.The PAH concentrations found in this study were moderate compared to PAH concentrations found in run-offs in other studies.The main PAH components in the rainwater,roof run-off,and asphalt road run-off samples were 3-ring PAHs,3–4-ring PAHs,and 4–6-ring PAHs,respectively.Source apportionment results indicated that combustion(47.4%–55.5%) and vehicular emissions(30.5%–33.0%) were the major contributors to PAHs in roof run-off.Vehicular emissions were the most significant contributors to asphalt road run-off(47.2%),followed by combustion(23.5%),and petroleum(16.3%).Vehicular emissions and coal and natural gas combustion are therefore the most significant sources of PAHs in run-off from impervious surfaces in the Shanghai urban area.
文摘Under the condition of different precipitation intensities, different gradients, different land-use types and different vegetation coverage, the soil erosion and transference of element (or pollutant) are studied by simulating and analyzing the surface run-off of experimental plots in the catchment area of Songhua Lake, with an area of about 43 370.8km2. And the influencing factors that produce the spatial difference are analyzed and assessed. It is put forward that the irrational land utilization is the reason of soil erosion and pollutant run-off. The gradient of farmland, the growing season of vegetation and the vegetation coverage are chiefly restricting factors that lead to the soil erosion and pollutant run-off. This study can provide the fundamental data for comprehensive planning and harnessing of the non-point source pollution in the valley.
文摘Run-off-road crashes in the United States have become a major cause of serious injuries and fatalities. A significant portion of run-off-road crashes are single vehicle crashes that occur due to collisions with fixed objects and overturning. These crashes typically tend to be more severe than other types of crashes. Single vehicle run-off-road crashes that occurred between 2004 and 2008 were extracted from Kansas Accident Reporting System (KARS) database to identify the important factors that affected their severity. Different driver, vehicle, road, crash, and environment related factors that influence crash severity are identified by using binary logit models. Three models were developed to take different levels of crash severity as the response variables. The first model taking fatal or incapacitating crashes as the response variable seems to better fit the data than the other two developed models. The variables that were found to increase the probability of run-off-road crash severity are driver related factors such as driver ejection, being an older driver, alcohol involvement, license state, driver being at fault, medical condition of the driver;road related factors such as speed, asphalt road surface, dry road condition;time related factors such as crashes occurring between 6 pm and midnight;environment related factors such as daylight;vehicle related factors such as being an SUV, motorcycles, vehicle getting destroyed or disabled, vehicle maneuver being straight or passing;and fixed object types such as trees and ditches.
基金National Basic Research Program of China(973 Program)(2010CB428403)The Natural Science Foundation of China(40901023).
文摘Aims The Miyun Reservoir is the most important drinking water source for Beijing—the capital of China with a population of more than 16 million.Since the 1980s,the inflow to the reservoir has been decreasing,which seriously threatens the security of water use in Beijing.Our goal was to analyze the impact of land use and cover change(LUCC)on run-off yield in the upstream of the Miyun Reservoir.Methods In this study,the Soil andWater Assessment Tool(SWAT)was used to simulate the impacts of LUCC on the run-off yield in the Bai River catchment—upstream of the Miyun Reservoir basin in northern China.The investigation was conducted using two 6-year historical streamflow records:from 1986 to 1991 and from 2000 to 2005.A split sample procedure was used for model calibration and validation.The data from 1986 to 1988 and from 2000 to 2002 were used for calibration,while those from 1989 to 1991 and from 2003 to 2005 for validation.The SWAT calibration was based on monthly measured discharge at Zhangjiafen station at the catchment outlet from Bai River catchment.Additionally,the influence of LUCC on the surface run-off was distinguished from that of climate change on the surface runoff through SWAT scenarios modeling,the twoway analysis of variance(ANOVA),and the rainfall–run-off double-mass analysis in the Bai River catchment.Important Findings We found that the SWAT model could be used successfully to accurately simulate run-off yield and different LUCC patterns affecting water quantity in this catchment.During calibraion for the two periods the simulated monthly run-off satisfactorily matched the observed values,with the Nash–Sutcliffe coefficient>0.9 and 0.7 and a coefficient of determination of 0.9 and 0.65 at the outlet station(Zhangjiafen station),while during validation for the two periods the obtained values were 0.85,0.65 and 0.9,0.65,respectively.During the period of 1986–91,both the SWAT scenarios modeling and the analysis of the two-way ANOVA method showed that LUCC and climate change had some impact on run-off,and the impact of climate change was more significant than that of LUCC.Compared with the period during 1986–91,the run-off yield in the period during 2000–05 significantly decreased.The obtained results from the rainfall–run-off double-mass analysis indicate that since 1998 LUCC has had an increasing influence on the run-off,while the response of the run-off to rainfall has been decreasing.Since 1998,the LUCC has been a major driving force for run-off change in Bai River catchment.
