华北土石山区油松林对降雨再分配的影响

森林对大气降雨的再分配有着重要的作用,2010年通过对河北省木兰国营林场油松林穿透降雨、冠层截留量和树干径流的观测,分析了华北土石山区油松林降雨再分配的特征。结果表明:油松林的穿透降雨量、冠层截留量和树干径流量分别占大气降雨量的67.07%,29.79%,3.10%。油松林冠层穿透降雨量和树干径流量与林外降雨量呈明显的线性关系(R2=0.986,R2=0.893),林冠截留量与降雨量成幂函数关系(R2=0.765);根据回归方程,当林外降雨量大于0.264mm时,可发生穿透降雨,当林外降雨量大于4.89mm时,可发生树干径流;林冠在降雨再分配过程中起着主要的作用,在空间和时间上都进行了再分配。

Study on Effect of Pinus tabulaeformis Plantation on Rainfall Redistribution Processes in the Mountainous Area of North China

Forestry plays an important role in the atmosphere rainfall redistribution.Throughfall,stemflow and canopy interception of a natural forest stand of Pinus tabulaeformis in Mulan in Hebei Province of China were observed in 2010.The characteristic of rainfall redistribution of Pinus tabulaeformi in the mountainous was analyzed.The results showed that the rainfall,canopy interception and stem flow accounted for 69.07%,29.79%,3.10% of total rainfall,respectively.Throughfall,stemflow had significant relationship with total rainfall(R2=0.986,R2=0.893).Relation between canopy interception and rainfall could be described by a power function(R2=0.765);according to the regression equation,when the rainfall outside the forest was greater than 0.264 mm,the penetration of rainfall could occur,when rainfall outside the forest was greater than 4.89 mm,the runoff of trunk could occur;canopy in the process of redistribution rainfall played a major role in spatio-temperal redistribution.