摘要
基于人工模拟降雨研究了三峡库区25°径流小区侵蚀泥沙对0.285,0.978,1.737 mm/min 3种不同降雨强度的响应特征。结果表明:在降雨过程中径流泥沙量,随产流历时的增加呈现先增加后逐渐减少,最终趋于稳定。侵蚀泥沙峰值量出现的时间随着雨强的增大在整个产流历程中不断提前。坡面径流的累积产沙量随产流历时的增加呈幂函数规律,相同降雨历时大降雨强度的累积产沙量明显高于小降雨强度的累积产沙量。在降雨强度为0.285,0.978,1.737 mm/min时,侵蚀泥沙中大颗粒的砂粒含量随产流历时的增加大致呈现降低趋势,侵蚀泥沙中细颗粒的粘粒及粉粒含量随着产流历时的增加呈现增加的趋势,但不同降雨强度下侵蚀泥沙机械组成的波动性有显著差异,雨强越大,侵蚀泥沙机械组成与产流历时回归模型拟合越好。
The response characteristic of eroded sediment in 25° runoff plots was studied based on three different simulated rainfall intensity which were 0.285 mm/min,0.978 mm/min and 1.737 mm/min,respectively.The results were as follows： The quantity of runoff sediment increased firstly and then reduced gradually and tended to be stable finally with the runoff duration extended during rainfall process.The time of peak quantity of eroded sediment occurred brought forward constantly along with the increase of rainfall intensity during runoff generation process.Accumulative sediment-runoff of slope runoff showed a relationship of power function with the increase of runoff duration.Accumulative sediment runoff with large rainfall intensity was obviously larger than that of small rainfall intensity.With the same runoff duration,when rainfall intensity were 0.285 mm/min,0.978 mm/min and 1.737 mm/min,the content of sand in eroded sediment decreased roughly,and the content of clay and silt increased roughly with the increase of runoff duration.But the variation of particle size composition of eroded sediment was obvious different under different rainfall intensities.The larger rainfall intensity was,the better eroded sediment particle size composition and runoff duration regression model fit.
出处
《水土保持学报》
CSCD
北大核心
2011年第2期19-23,共5页
Journal of Soil and Water Conservation
基金
西南大学博士基金项目(SWU110023)
国家科技支撑计划重点项目(2008BAD98B01)
西南大学生态学重点学科“211工程”建设经费资助项目
关键词
人工模拟降雨
紫色土
陡坡地
侵蚀泥沙
simulated rainfall
purple soil
steep slope land
eroded sediment
