【摘要】 在黄土丘陵沟壑区小流域侵蚀水沙耦合数学模型基础上,以黄河中游典型流域岔巴沟流域为研究对象,根据工程水文学设计暴雨的方法生成各种假设暴雨过程,在固定下垫面不变的条件下,进行模拟计算并分析流域100年一遇、50年一遇和10年一遇设计暴雨的产流产沙效应。在几种不同的假设植被覆盖度下,分别模拟计算同一场典型暴雨在不同植被覆盖条件下的水沙侵蚀过程。模拟结果表明:1)根据岔巴沟流域100年一遇(P=0.01)、50年一遇(P=0.02)和10年一遇(P=0.1)设计暴雨3种情景下的水沙计算特征可知,100年一遇降雨(P=0.01)对应的洪峰流量和沙峰分别为805 m3/s和77.5万kg/s,50年一遇降雨(P=0.02)对应的洪峰流量和沙峰分别为595 m3/s和50.2万kg/s,10年一遇降雨(P=0.1)对应的洪峰流量和沙峰分别为108 m3/s和12.1万kg/s,根据以上计算结果可大致推断1970—2000年的绝大多数侵蚀观测场次的水沙重现期在10年一遇和50年一遇之间;2)该流域植被覆盖度的减水减沙效应显著,增加25%植被覆盖将减少水量73%和沙量84%,而减少25%的植被覆盖将增加29.9%的径流和18.6%的泥沙。不同降雨和植被覆盖条件下的水沙侵蚀过程情景模拟分析结果可为黄土高原丘陵沟壑区流域水土保持工程规划与设计提供依据。更多还原

【Abstract】 Based on the runoff and sediment yield mathmatical model for the Chabagou catchment in Hilly-gully region,a typical small catchment in the middle stream of Yellow River,was selected to simulate the runoff and sediment yield under several various possible situations.Firstly three designing precipitation schemes with the occurring period of 100,50 and 10 years respectively were computed and used in runoff and sediment yield simulation.Then three vegetation cover schemes were used in the scenario simulation.Results indicate: 1) The flood and sediment transport peak for the designing-strom event with 100-year period(P=0.01) is 805 m3/s and 775×103 kg/s,it is 595 m3/s,502×103 kg/s for those of 50-year period(P=0.02) and 108 m3/s,121×103 kg/s for those of 10-year period(P=0.1),It can be inferred that the occurring period of 19890701 storm event is between 100 and 50 years according to the simulation results;2) The positive impacts of vegetation coverage on reduction of water yield and soil erosion of catchment are detected,in which,reduction of 73% and 84% for water yield and sediment yield with 25% decreasing of vegetation coverage are identified,whilst,the simulated water and sediment yield will increase by 29.9% and 18.6% if the study catchment suffers 25% decreasing of vegetation coverage.The results of this investigation will be greatly benificial to regional,soil and water conservation planning and designing in Hilly-gully region.更多还原