Study on Hydro-ecological Benefits of Evergreen Broad-leaved Forest at the Qiandao Lake Region

Scaled dams location observation of hydrological dynamics of evergreen broad leaved forest at the Qiandao Lake region was conducted for 8 consecutive years from 1986 to 1993.A 10 8 hm2 forest consisting of Castanopsis sclerophlla and Lithocarpus glaber was selected for trial.From 1987 to 1992,the annual precipitation and evaporation averaged 1 410 mm and 908 mm, while the water flow of this forest averaged 4 079 m3, which was equal to 407 9 mm or 28 9% of the average annual precipitation, the water flow averaged 108～158 m3·d-1 in rainy season, 68～86 m3·d-1 in normal season, and less than 40 m3·d-1 in dry season with the least of 7 9 m3·d-1. The evergreen broad leaved forest has strong water maintenance capacity and forms a sustainable and favorable hydrological ecology.