A Model Of Rainfall Interception By Inhomogeneous Forest Canopy

The process of rainfall interception by inhomogeneous forest canopy composed of tree crowns with some gaps among them has been considered, and the previous theoretical model of rainfall interception has been generalized from statistically homogeneous canopy to inhomogeneous canopy as well.The essay mainly dealt with the following contents. Firstly the process of rainfall interception in tree crowns and that of rainfall in the gaps among them were studied respectively to acquire the average rainfall interception in the forest canopy. Besides, based on the model derived by Liu Jiagang (1988) and setting the value of closing degree, both the relevant partial differential equations and a formula to estimate rainfall interception were derived. Moreover, the new model is resolved through numerical method and is illustrated with typical values of some ecological factors and three groups of curves were aqucired through the calculation with VisualBasic program, thereafter similar results of interception, interception rate, throughfall and throughfall rate were acquired through calculation based on the model derived in the essay and the parameters gathered by Dong Shiren (1986) in Longhua, Hebei Province.A model of rainfall interception by inhomogeneous forest canopy has been derived through research. It belongs to the multi-layer model which distinguishes from quite a few models in history (they belongs to the whole model in which all the parameters represent the whole canopy); however, the results of the model derived in the essay include those of the models mentioned earlier and the relationship between interception and each ecological factors was depicted in more detail.