A Study on Characteristics of Runoff in Forest Plantation of Cunninghamia lanceolata and Pinus massoniana

In 1984~1990, precipitation, runoff and soil moisture in the 22-year-old plantation of Cunninghamia lanceolata Lamb, and Pinus massoniana (Lamb.) Hook, were measured. Some results from 2 small experimental forest watersheds and 2 runoff plots are presented. The ranges of the average annual runoff were 15.648mm to 31.148mm, or 1.245% to 2.537% (annual runoff coefficient). Maximum runoff in a time period is about 2.16mm to 24.587mm or 3.07% to 31.35% (runoff coefficient). According to the analysis of multi-regression, runoff (y) approximates precipitation (x) in exponential cure regression, its equation is y=abx (a, b be parameter).