The runoff simulation and the effect of human activities on runoff in the Source Area of Three Rivers

Applying actual meterage statistical data of precipitation, temperature, evaporation and runoff, Using Excel and SPSS software and multi-linear regression analysis, researched the change of hydrological environment and assessed artificial effects on inartificial runoff in the Source Area of Three Rivers. It is concluded that runoff change takes on leading characteristic and the region is start-up area of runoff change. Temperature and precipitation have the effect to increase runoff, evaporation has the effect to reduce runoff and artificial effect on runoff was lesser before 1982. The artificial effects on runoff had increase trend after 1983. The artificial effects are all under 50 percent in Jimai and Tangnaihai and from 50 percent to 80 percent in Huangheyan in most years. The dominant factors which influenced runoff change are natural factors in the east and artificial factors in the west in the source of Yellow River, namely there is the regional difference of fierceness in the west and feebleness on artificial effects on runoff, the closer to headstream area, the stronger artificial effects are.