黄土高原沟壑区典型小流域不同洪水类型的侵蚀输沙特征

摘要

为明确黄土高原沟壑区不同洪水类型及不同水土保持治理时期的径流侵蚀输沙特征,根据相关标准从1964-1985年间的流域径流事件中挑选出100场洪水,利用快速聚类法和判别聚类法将筛选出来的100场洪水事件分成A、B、C三类,三种洪水类型表现出各异的径流输沙规律:累计径流量和累计输沙量所占比例最高的洪水类型为A型和C型洪水,所占比例分别为64％和74％;在流域产流能力上C型洪水的产流能力最强,B型洪水次之;根据方差分析结果,洪水类型对流域降雨产流能力、水土流失程度以及流域水沙关系均具有一定的影响,径流系数和输沙模数的显著减少和洪峰流量的降低表明多年来所进行的各类水保措施起到了拦蓄径流泥沙、削减洪峰的生态效用.%In order to clarify the flood type's characteristic of runoff and erosion in Gully region of Loess Plateau,100 floods are selected from the flood events which happened during 1964-1985 according to the related standards.And then those floods are classified into A,B and C with the help of the fast clustering method and the discriminant clustering method.Correspondingly they have their own trait with type A and type C possessing the highest accumulative runoff and sediment which are 64 ％ and 74 ％ respectively.Type C has the strongest runoff generation capacity,with the second strongest being type B.According to the variance analysis,flood type has an impact on runoff generation capacity,soil erosion degree and water-sediment relationship,and reduces the runoff coefficient with sediment transport modulus means soil conservation measures coming into effect.