Fraction of incident rainfall within the canopy of a pure stand of Pinus armandii with revised Gash model in the Liupan Mountains of China

Abstract

Summary The throughfall, stemflow and interception during the growing season (June–September) of 2005 were observed in a pure stand of natural Pinus armandii forest in the Liupan Mountains of northwestern China. The results indicate that of the 544.0 mm of cumulative gross rainfall generated by 15 sampled events, throughfall, stemflow and canopy interception were 462.2 mm (84.96%), 4.8 mm (0.88%), and 77.0 mm (14.15%), respectively. The revised Gash analytical model of rainfall interception was employed and the simulated interception values were close to the observed with an underestimation of 5.87%. Moreover, 39.48% and 55.24% of interception were evaporated from canopy in the stages of “during storms” and “after storms”, respectively. The revised Gash analytical model is highly sensitive to changes regarding canopy storage capacity (S), cover (c) and the climate parameters of rainfall intensity R and evaporation E ¯ .