Study on Storm Runoff in Small Scrub Watersheds on Xishan Mountain in Beijing

Making use of the actual runoff datum of 6 watersheds with vegetations of natural secondary shrubbery forest,IUH method was adopted to analyze the major factors which are influencing the amount of runoff in the Xishan Mountain, Beijing.And a prediction of the amount of runoff was made.The results showed that:IUH method can well be applied for small watershed;the natual secondary shrubbery forest posesses fine water supply capacity.When the forest coverage is above 40%,each 10% increase can decrease 4.6% of IUH high discharge,and prolong 9.3% of high discharge time.