Canopy interception simulation of pine plantation in Miyun of Beijing

【Objective】 The study explored the eco-hydrological processes of pine plantation in Miyun reservoir watershed of Beijing and its mechanism. 【Method】 In this paper , revised Gash canopy interception model was applied to simulate the canopy interception amount of Pine plantation based on the 21field rainfall data , weather information and forest structure data from May to October in 2006. 【Result】 The total amounts of canopy interception , trunk runoff and throughfall were 57.33 , 1.03and 229.51mm.The simulated values of canopy interception and trunk runoff decreased by 12.6mm and 0.39mm respectively compared with the measured value , with the relative error being 18.02%and 27.46%.The simulated values of throughfall was higher than the measured value through 13.17mm , with the relative error being 6.09%.The simulated values of cumulative amount of canopy interception was less than the measured value , with minimum relative error being 6% , maximum 32.64% , 76.2% between 20%-30% and average 25.2%. 【Conclusion】 Model could better simulate cumulative amount of canopy interception of pine plantation in Miyun of Beijing.However when the model was applied in pine plantation of this area , the simulated values of cumulative amount of canopy interception should add 25.2%of the measured value to achieve accuracy.