The impact of forest cover degree of surface for runoff and geological environmental

The paper discusses the relationship of the forest cover rate and the quantity of surface flow of two typical basins in LuZhong mountain area in more than forty years. The result shows that : the increase of the forest cover rate ,helps to the supply of precipitation to the ground water ,and helps to slow down the drainage speed of the precipitation, reduce the flood peak flow in flood season in mountain areas ,which could reduce the arises of debris flow disasters; At the same time add the output of ground water in dry season ,which means add it´s dry season runoff. It concludes that the increase of one basin´s forest cover rate is helpful to the flood control of a reservoir in north area which has long dry season and concentrative precipitation time and helpful to water resources development and utilization. On the hand, the development of forest cover has significant effect to ground geohydrologic environment that the groundwater recharge from precipitation is increased.