Vegetative coverage is commonly used to reduce urban slope soil erosion.Laboratory experimental study on soil erosion under grass covered slopes is conventionally time and space consuming.In this study,a new method is...Vegetative coverage is commonly used to reduce urban slope soil erosion.Laboratory experimental study on soil erosion under grass covered slopes is conventionally time and space consuming.In this study,a new method is suggested to study the influences of vegetation coverage on soil erosion from a sloped loess surface under three slope gradients of 51,151,and 251;four rye grass coverages of 0%,25%,50%,and 75%;and three rainfall intensities of 60,90,and 120 mm/h with a silt-loamy loess soil.Rye grasses were planted in the field with the studied soil before being transplanted into a laboratory flume.Grass was allowed to resume growth for a period before the rain simulation experiment.Results showed that the grass cover reduced soil erosion by 63.90%to 92.75%and sediment transport rate by 80.59%to 96.17%under different slope gradients and rainfall intensities.The sediment concentration/sediment transport rate from bare slope was significantly higher than from a grass-covered slope.The sediment concentration/transport rate from grass-covered slopes decreased linearly with grass coverage and increased with rainfall intensity.The sediment concentration/transport rate from the bare slope increased as a power function of slope and reached the maximum value at the gradient of about 251,whereas that from grass-covered slope increased linearly and at much lower levels.The results of this study can be used to estimate the effect of vegetation on soil erosion from loess slopes.展开更多
基金This research was financially funded by Science and Technique Development Foundation of the Yellow River Institute of Hydraulic Research(No.200651)the Foundation of State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau(Grant no.10501-245).
文摘Vegetative coverage is commonly used to reduce urban slope soil erosion.Laboratory experimental study on soil erosion under grass covered slopes is conventionally time and space consuming.In this study,a new method is suggested to study the influences of vegetation coverage on soil erosion from a sloped loess surface under three slope gradients of 51,151,and 251;four rye grass coverages of 0%,25%,50%,and 75%;and three rainfall intensities of 60,90,and 120 mm/h with a silt-loamy loess soil.Rye grasses were planted in the field with the studied soil before being transplanted into a laboratory flume.Grass was allowed to resume growth for a period before the rain simulation experiment.Results showed that the grass cover reduced soil erosion by 63.90%to 92.75%and sediment transport rate by 80.59%to 96.17%under different slope gradients and rainfall intensities.The sediment concentration/sediment transport rate from bare slope was significantly higher than from a grass-covered slope.The sediment concentration/transport rate from grass-covered slopes decreased linearly with grass coverage and increased with rainfall intensity.The sediment concentration/transport rate from the bare slope increased as a power function of slope and reached the maximum value at the gradient of about 251,whereas that from grass-covered slope increased linearly and at much lower levels.The results of this study can be used to estimate the effect of vegetation on soil erosion from loess slopes.
