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以武陵山区女儿寨小流域为研究区,根据流域2004—2008年77场典型降雨径流观测资料,研究流域次降雨径流与产沙特征。结果表明:77场降雨中,以25.0～49.9 mm和50.0～100.0 mm的降雨为主,占降雨总数的67.53%,降雨强度以10～40 mm/h为主;降雨量与径流深和产沙模数呈现较为显著的线性相关性,降雨量、径流深及降雨侵蚀力对产沙模数均有明显影响,其中以径流深和产沙模数的拟合效果最好,R2达0.684 7;在对降雨、径流、产沙共12个指标进行相关性分析的基础上,对径流深、洪峰流量、产沙模数、降雨侵蚀力4个主要指标进行多元逐步回归拟合,R2均在0.85以上,并通过显著性检验,回归方程拟合效果较好,可用于相关指标的定量计算;流域的产沙量主要取决于几次大的暴雨,汛期的降雨决定流域的产流产沙状况。研究结果可为流域水土流失监测和预报、水土保持措施合理配置等提供相应参考。
Based on the data of 77 typical rainfall and runoff in the basin from 2004 to 2008, a case study was conducted to study the characteristics of secondary rainfall runoff and sediment yield. The results showed that rainfalls of 25.0-49.9 mm and 50.0-100.0 mm were the main rainfalls in 77 rainstorms, accounting for 67.53% of the total rainfall and rainfall intensity of 10-40 mm / h. Rainfall, runoff and sediment yield The modulus showed a significant linear correlation. Rainfall, runoff depth and rainfall erosivity had a significant effect on the sediment yield, of which runoff depth and sand production modulus were the best, R2 was 0.684 7; On the basis of the correlation analysis of 12 indicators of rainfall, runoff and sediment yield, the multiple stepwise regression fitting was performed on the four major indexes of runoff depth, flood peak flow rate, sediment yield rate and rainfall erosivity. The R2 was 0.85 , And through the significance test, regression equation fitting effect is better, can be used for the quantitative calculation of related indicators; sediment yield in the basin mainly depends on several heavy rain, rainfall in the raining season determines runoff and sediment yield status. The results can provide reference for the monitoring and forecast of soil and water loss in the basin and the rational allocation of soil and water conservation measures.