降雨类型和水土保持对黄土区小流域水土流失的影响  

Effect of Rainstorm Patterns and Soil Erosion Control Practices on Soil and Water Loss in Small Watershed on Loess Plateau

作　　者：晏清洪[1] 原翠萍 雷廷武[1] 雷启祥[3] 张满良[3] 苏广旭[3] 

机构地区：[1]中国农业大学水利与土木工程学院,北京100083 [2]北京国泰天平行土地规划设计有限公司,北京100873 [3]黄河水利委员会天水水土保持科学试验站,天水741000

出　　处：《农业机械学报》2014年第2期169-175,共7页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金资助项目(40635027);黄河水土保持生态工程天水藉河重点支流治理(二期)项目

摘　　要：对黄土区桥子东沟流域的143场次洪水事件水文泥沙数据进行统计分析,并利用K均值分类法划分降雨类型,比较不同降雨类型条件下流域水土流失特征,探讨水土保持治理对不同降雨类型下流域产流输沙的影响。结果表明,次降雨量和最大30 min雨强是影响流域产流输沙的主要降雨特征。降雨事件划分为4种类型:Ⅰ型(小雨量、小雨强)、Ⅱ型(大雨量、大雨强)、Ⅲ型(大雨量、小雨强)和Ⅳ型(小雨量、大雨强)。4种降雨类型下次洪水事件的产流能力和洪峰流量由大到小依次为Ⅱ型、Ⅳ型、Ⅲ型和Ⅰ型。频次最少的Ⅱ型降雨次洪水事件的输沙量最多,Ⅰ型、Ⅲ型和Ⅳ型降雨条件下次洪水事件输沙量的差异不显著,输沙量均较少。水土保持综合治理显著减少了流域径流量和输沙量,其中Ⅱ型降雨次洪水事件减水量和减沙量最多,Ⅰ型最少。Runoff and sediment data from 1987 to 2010, 143 flood events of Qiaozi East watershed （QE） on the loess plateau were used to investigate the relationships among rainfall, runoff and suspended sediments. K-means clustering of different rainstorm patterns was used to differentiate watershed runoff and sedimentation features and to quantify the impacts of erosion control practices on runoff and sediment production. The results indicated that the precipitation （P） and the maximal 30 minutes rainfall intensity （I30max） were the most relevant factors to runoff and sediment responses. The rainfall events were divided into four rainstorm patterns, as Pattern Ⅰ （low P and low I30max）, Pattern Ⅱ （high P and high Ⅰ30max） , Paatern Ⅲ（high P and low I30max） and Pattern Ⅳ （low P and high Ⅰ30max）. The runoff generated by the storms, in term of peak discharges from low to high were in the order of Pattern Ⅱ storms, Pattern IV, Pattern Ⅲ and Pattern Ⅰ . Pattern Ⅱ , though the fewest in occurrences, produced the most sediments while Pattern IV, Pattern Ⅲ and Pattern Ⅰ storms produced limited sediments with no significant differences. The soil and water conservation practices significantly reduced runoff and sediment of the watershed, especially for the highest sediment production events of Pattern Ⅱ.

关 键 词：黄土区 小流域 水土流失 降雨类型 水土保持 

分 类 号：TV122[水利工程—水文学及水资源] S157[农业科学—土壤学]