In this study, laboratory rainfall simulation experiments were conducted to investigate the regulatory effects of grass coverage on rainfallrunoff processes. A total of 80 grass blocks planted with well-grown manilagr...In this study, laboratory rainfall simulation experiments were conducted to investigate the regulatory effects of grass coverage on rainfallrunoff processes. A total of 80 grass blocks planted with well-grown manilagrass, together with their root systems, were sampled from an eastern suburban area of Xi'an City in the northwest arid area of China and sent to a laboratory for rainfall simulation experiments. The runoff and infiltration processes of a slope with different grass coverage ratios and vegetation patterns were analyzed. The results show that the runoff coefficient decreases with the increase of the grass coverage ratio, and the influence of grass coverage on the reduction of runoff shows a high degree of spatial variation. At a constant grass coverage ratio, as the area of grass coverage moves downward, the runoff coefficient, total runoff,and flood peak discharge gradually decrease, and the flood peak occurs later. With the increase of the grass coverage ratio, the flood peak discharge gradually decreases, and the flood peak occurs later as well. In conclusion, a high grass coverage ratio with the area of grass coverage located at the lower part of the slope will lead to satisfactory regulatory effects on rainfall-induced runoff.展开更多
降雨条件下公交港湾式停靠站区域易产生积水,不仅会损害停靠区域路面健康,而且严重影响乘客出行体验与道路通行效率。北方地区城市有其独特的自然地理气候特征,低影响开发措施的设置具有局限性。以分隔带类型的港湾停靠站路段为研究对象...降雨条件下公交港湾式停靠站区域易产生积水,不仅会损害停靠区域路面健康,而且严重影响乘客出行体验与道路通行效率。北方地区城市有其独特的自然地理气候特征,低影响开发措施的设置具有局限性。以分隔带类型的港湾停靠站路段为研究对象,分析了传统港湾停靠站路段雨水处理模式及其存在的问题,结合北方地区道路适用的低影响开发措施,提出了港湾停靠站路段低影响开发设施布局方案,并分析了雨水径流排放机制。通过暴雨洪水管理模型(Storm Water Management Model, SWMM)软件模拟研究路段海绵模式下雨水径流的调控效果,发现研究区域低影响开发设计对雨水径流具有明显的削减和延迟作用。展开更多
Though being considered strategically important in matters of national defense based on its abundance of natural resources,Northwest China is one of the most ecologically vulnerable areas in the country. As one of the...Though being considered strategically important in matters of national defense based on its abundance of natural resources,Northwest China is one of the most ecologically vulnerable areas in the country. As one of the region's important water sources,glaciers have gone through major changes due to climate change. An analysis of research results over the past 60 years reveals that the glaciers have been retreating in general to some degree in large river basins in Northwest China,but the rate of retreating varied largely among different regions,ranging from 0. 01% ·a^(-1) to 0. 75% ·a^(-1). Specifically,glaciers around the Lantsang River Basin and the Altay Mountains have been retreating fastest. The retreat of glaciers has already caused an increase in runoff in mountainous areas of Northwest China. Meanwhile,increases in the frequency of glacial flash floods and in the flood discharge will further enhance the probability of glacial lake outburst floods and ensuing disasters.展开更多
Assessing the effects of vegetation on water and soil conversation is the key basis for research and management of ecological restoration on water-eroded areas.In this study,the runoff depth,soil loss and correspondin...Assessing the effects of vegetation on water and soil conversation is the key basis for research and management of ecological restoration on water-eroded areas.In this study,the runoff depth,soil loss and corresponding precipitation of five plots planted respectively with Pueraria lobata,Lespedeza bicolor Turcz,Manglietia yuyuanensis Law,Paspalum natatu Fliigge,Paspalum wettsteinii Hackel and one control plot were observed monthly from 2003 to 2010 in Hetian Town of Changting County,Fujian Province,a typical water-eroded area in southern China.Then the effects of different vegetation on water/soil conversation(RE/SE)were determined using the ratios of runoff depth/soil loss between vegetated plots to the control plot.Meanwhile,the effect of precipitation on the water and soil loss was also analyzed.The results showed that,both the water and soil conservation effects of Pueraria lobata and Manglietia yuyuanensis Law are better than Lespedeza bicolor Turcz and Paspalum natatu,while Paspalum wettsteinii Hackel are the worst.The differences of effects of water conservation are more significantly than those of soil conversation between five kinds of vegetations.The runoff depth is mainly affected by precipitation,the determination coefficients(R2)of linear regression models between precipitation and runoff depth of all planted plots are all greater than 0.9,whereas the determination coefficients of the linear regression models between precipitation and soil loss vary form 0.3 to 0.8 for different vegetated plots.These results provide a reference for vegetation reconstruction in the current and similar areas.展开更多
The identification of runoff generating areas (RGAs) within a watershed is a difficult task because of their temporal and spatial behavior. A watershed was selected to investigate the RGAs to determine the factors aff...The identification of runoff generating areas (RGAs) within a watershed is a difficult task because of their temporal and spatial behavior. A watershed was selected to investigate the RGAs to determine the factors affecting spatio-temporally in southern Ontario. The watershed was divided into 8 fields having a Wireless System Network (WSN) and a V-notch weir for flow and soil moisture measurements. The results show that surface runoff is generated by the infiltration excess mechanism in summer and fall, and the saturation excess mechanism in spring. The statistical analysis suggested that the amount of rainfall and rainfall intensity for summer (R2 = 0.63, 0.82) and fall (R2 = 0.74, 0.80), respectively, affected the RGAs. The analysis showed that 15% area generated 85% of surface runoff in summer, 100% of runoff in fall, and 40% of runoff in spring. The methodology developed has potential for identifying RGAs for protecting Ontario’s water resources.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51609196)
文摘In this study, laboratory rainfall simulation experiments were conducted to investigate the regulatory effects of grass coverage on rainfallrunoff processes. A total of 80 grass blocks planted with well-grown manilagrass, together with their root systems, were sampled from an eastern suburban area of Xi'an City in the northwest arid area of China and sent to a laboratory for rainfall simulation experiments. The runoff and infiltration processes of a slope with different grass coverage ratios and vegetation patterns were analyzed. The results show that the runoff coefficient decreases with the increase of the grass coverage ratio, and the influence of grass coverage on the reduction of runoff shows a high degree of spatial variation. At a constant grass coverage ratio, as the area of grass coverage moves downward, the runoff coefficient, total runoff,and flood peak discharge gradually decrease, and the flood peak occurs later. With the increase of the grass coverage ratio, the flood peak discharge gradually decreases, and the flood peak occurs later as well. In conclusion, a high grass coverage ratio with the area of grass coverage located at the lower part of the slope will lead to satisfactory regulatory effects on rainfall-induced runoff.
文摘降雨条件下公交港湾式停靠站区域易产生积水,不仅会损害停靠区域路面健康,而且严重影响乘客出行体验与道路通行效率。北方地区城市有其独特的自然地理气候特征,低影响开发措施的设置具有局限性。以分隔带类型的港湾停靠站路段为研究对象,分析了传统港湾停靠站路段雨水处理模式及其存在的问题,结合北方地区道路适用的低影响开发措施,提出了港湾停靠站路段低影响开发设施布局方案,并分析了雨水径流排放机制。通过暴雨洪水管理模型(Storm Water Management Model, SWMM)软件模拟研究路段海绵模式下雨水径流的调控效果,发现研究区域低影响开发设计对雨水径流具有明显的削减和延迟作用。
基金Supported by the China National Natural Science Foundation(41401084,41471060)the International Partnership Program of Chinese Academy of Sciences(131C11KYSB20160061)
文摘Though being considered strategically important in matters of national defense based on its abundance of natural resources,Northwest China is one of the most ecologically vulnerable areas in the country. As one of the region's important water sources,glaciers have gone through major changes due to climate change. An analysis of research results over the past 60 years reveals that the glaciers have been retreating in general to some degree in large river basins in Northwest China,but the rate of retreating varied largely among different regions,ranging from 0. 01% ·a^(-1) to 0. 75% ·a^(-1). Specifically,glaciers around the Lantsang River Basin and the Altay Mountains have been retreating fastest. The retreat of glaciers has already caused an increase in runoff in mountainous areas of Northwest China. Meanwhile,increases in the frequency of glacial flash floods and in the flood discharge will further enhance the probability of glacial lake outburst floods and ensuing disasters.
基金Supported by National Natural Science Foundation of China(41071281)
文摘Assessing the effects of vegetation on water and soil conversation is the key basis for research and management of ecological restoration on water-eroded areas.In this study,the runoff depth,soil loss and corresponding precipitation of five plots planted respectively with Pueraria lobata,Lespedeza bicolor Turcz,Manglietia yuyuanensis Law,Paspalum natatu Fliigge,Paspalum wettsteinii Hackel and one control plot were observed monthly from 2003 to 2010 in Hetian Town of Changting County,Fujian Province,a typical water-eroded area in southern China.Then the effects of different vegetation on water/soil conversation(RE/SE)were determined using the ratios of runoff depth/soil loss between vegetated plots to the control plot.Meanwhile,the effect of precipitation on the water and soil loss was also analyzed.The results showed that,both the water and soil conservation effects of Pueraria lobata and Manglietia yuyuanensis Law are better than Lespedeza bicolor Turcz and Paspalum natatu,while Paspalum wettsteinii Hackel are the worst.The differences of effects of water conservation are more significantly than those of soil conversation between five kinds of vegetations.The runoff depth is mainly affected by precipitation,the determination coefficients(R2)of linear regression models between precipitation and runoff depth of all planted plots are all greater than 0.9,whereas the determination coefficients of the linear regression models between precipitation and soil loss vary form 0.3 to 0.8 for different vegetated plots.These results provide a reference for vegetation reconstruction in the current and similar areas.
文摘The identification of runoff generating areas (RGAs) within a watershed is a difficult task because of their temporal and spatial behavior. A watershed was selected to investigate the RGAs to determine the factors affecting spatio-temporally in southern Ontario. The watershed was divided into 8 fields having a Wireless System Network (WSN) and a V-notch weir for flow and soil moisture measurements. The results show that surface runoff is generated by the infiltration excess mechanism in summer and fall, and the saturation excess mechanism in spring. The statistical analysis suggested that the amount of rainfall and rainfall intensity for summer (R2 = 0.63, 0.82) and fall (R2 = 0.74, 0.80), respectively, affected the RGAs. The analysis showed that 15% area generated 85% of surface runoff in summer, 100% of runoff in fall, and 40% of runoff in spring. The methodology developed has potential for identifying RGAs for protecting Ontario’s water resources.
