Abstract:Throughfall is an important part of effective rainfall in forest area. It accounts for more than 90% in quantity. The accurate measurements of throughfall is very difficult and also impossible because forest canopy is not well-distributed. This paper was based on some assumptions, a throughfall model in forest area was developed by mathematical way in terms of canopy interception mechanism. That is : If P0,U>0,W>0) If P≥U, then R=P-W Where U=W(b+1). U...