Analysis on the Characteristics of Surface Runoff and Baseflow in Qingshitan Reservoir

Taking inflow runoff into Qingshitan reservoir in Guilin city during 1958-1990 year as the research object, the digital filter technology is used to the base flow separation for runoff. The annual change characteristics of surface runoff and base flow is analyzed with the extreme ratio and coefficient of variation, the linear tendency linear method and Kendall rank correlation method are used to study the change trend of surface runoff and base flow. The results indicate that the annual runoff change of surface runoff is more unevenly, the surface runoff appear an increase trend, but the base flow appear a decline trend, the change trend of surface runoff and base flow is not obvious.