Precipitation Runoff Process and Affecting Factors of Phyllostachys pubescens Forests in Jinyun Mountain

The precipitation runoff of P.pubescens forests in Jinyun Mountain was studied using the observation data in runoff plots from 2002 to 2007.Combining the method of fractal dimension and grey correlation degree,factors affecting the process of precipitation runoff were studied.The study results were as follows: 1) From 2002 to 2007,the distribution of precipitation was somehow stable,72 % of the total rainfall occurred from April to September,and the peak of rainfall was in July;2) The surface runoff and underground runoff were closely related with rainfall,surface runoff and underground runoff accounted for 30.7 % and 15.2 % of the total rainfall respectively;3) The precipitation runoff of P.pubescens forests was affected by 6 factors;4) The factors ranked by the affecting extend were height,biodiversity,rainfall,litter,crown interception and soil porosity.