Rainfall-runoff Process and Tendency under Different Time Scale in Phyllostachys edulis Forest Land

Phyllostachys edulis forest is a typical vegetation type of forest ecological system in Jinyun Mountain. In order to reveal the influence of vegetation types to rainfall-runoff process, the paper studies the observed hydrological datas of runoff plots in Phyllostachys edulis forest area in 2002—2007 period. The outcomes show that ①in 2002—2007 period, the inter-annual distribution of precipitation in Phyllostachys edulis forest is stable, the rainfall relatively concentrates in April to September, making up 72% of a whole year and the peak value showing in July. ②The surface runoff and underground runoff keep a close corresponding relationship with rainfall. In the distribution of precipitation, surface runoff makes up 30.7% and groundwater runoff is 15.2%. ③In the future, the runoff in Phyllostachys edulis forest region shows a downward trend.