Rainfall-intercepting Capability of Forest Canopy

In order to judge functions of forest canopy intercepting rainfall objectively and compare interception of forest canopy among different forests,the idea of rainfall-intercepting capability of forest canopy was posed.The interception capability is the maximum of forest canopy intercepting any rainfall under ideal conditions.The interception capability increases along with rainfall.When rainfall is enough,the interception capability is equal to the interception capacity of forest canopy.Therefore,interception capacity is also the maximum of the interception capability.Based on some assumptions,the model of interception capability was developed in terms of theory on saturated runoff-generating of hydrology and hydrologic forecast,namely If PH,then I=αW[1-(1-P/H)β+1] If P≥H,then I=αWwhere,I is interception capability;P is rainfall;α is forest canopy density;H,W,and β are model parameters,H=W(β+1).Furthermore,by combining with observated data of a stand,approximately determination method of interception capability was introduced.Moreover,effectiveness of the model was also examined.The results show that calculation values with the model are almost same as approximate observed values and that interception capability model is effective.The model may be applied to different stands of any areas to compare and evaluate effects of forest canopy intercepting rainfall.