四川省紫色土地区小流域次降雨泥沙输移比探讨

选取四川省南部县鹤鸣观小流域与李子口小流域为研究区,在分布式侵蚀产沙模型侵蚀量计算值的基础上,探讨了小流域次降雨泥沙输移比.结果表明,在这两个流域,影响次降雨泥沙输移比的主要因素不同.在鹤鸣观小流域降雨量与径流深是影响泥沙输移比的主要因素,而在李子口流域,其主要因素为径流深与降雨强度.主要原因是鹤鸣观小流域的面积远小于李子口流域的面积,并且次降雨泥沙输移比随着流域面积增加而输移比逐渐减小.通过分析鹤鸣观小流域与李子口小流域次降雨泥沙输移比与降雨量、前期含水量、径流系数的关系得到了两个流域次降雨泥沙输移比公式.

Sediment Delivery Ratio Under Single Rainfall Events from Small Watershed in the Purple Soil Region of Sichuan Basin

This paper takes Hemingguan watershed and Lizikou watershed in Nanbu County,Sichuan Province as study areas and discusses the sediment delivery ratio(SDR) based on the distributed models of soil erosion and sediment yield from the two watersheds.Results show that the main factors affecting the SDR are different in the two watersheds.Rainfall amount and runoff volume are main factors in Hemingguan watershed but in Lizikou watershed,the main factors are runoff volume and rainfall intensity.The reason is that the size of Hemingguan watershed is much smaller than Lizikou watershed.Moreover,there is a tendency that the SDR for single rainfall gets smaller as the size of study area increases.Finally,the paper analyzes the relations of the SDR to rainfall amount,antecedent soil moisture,and runoff coefficient and constructs two formulas of SDR for the two watersheds.