Preliminary Analysis of Hydrological and Water Resources Effects under the Impact of Water and Soil Conservation Engineering in Fenhe River Basin
汾河流域水土保持措施水文水资源效应初析

According to the application of the distributed hydrological model(WEP-L model) with physical mechanism to the simulation of the hydrological cycle under different underlying surface data,this paper analyzes the quantitative influence of water and soil conservation engi-neering on hydrological cycle and water resources taking Fenhe River Basin as an exapmle.Two cases were described.Case I,the simulated underlying surface data in 2000 was used.Case II,the underlying surface data displacing the water and soil conservation engineering in 2000 with bare soil was used in the model.By contrast between Case I and Case II,the change and evolution of hydrological cycle and water resources have been investigated.The results showed that the local hydrological cycle as well as the quantity and compositions of water resources change distinctly under the impact of water and soil conservation engineering.Three main variations are as follows:(1)the vertical process of hydrological cycle was strengthened,each part of which including interception of surface,infiltration to soil,evaporation of soil and recharge of groundwater increased by 9.4%,1.8%,2.2% and 0.5%,respectively;(2)the horizontal process of hydrological cycle was weakened,each part of which such as direct surface runoff and base runoff decreased by 51.7% and 1.8% but interflow increased 4.9%;and(3) the surface water resources decreased 29.7% but groundwater resources nonoverlapped with surface water increased 5.1%,the special water resources reduced 23.2% but the general water resources increased 32.5% accompanied with 50.4% increase of the effective evaporation,namely,effective utilization of precipitation.The research achievement can be referenced to the studies on hydrological and water resources effects under impact of water and soil conservation engineering in other large watersheds.