长白山两种林型的降雨截留再分配特征与修正的Gash模型模拟

Canopy Rainfall Interception Characteristics of Two Typical Forest Types in Changbai Mountains and Its Revised Gash Model Simulation

为探究长白山地区两种林型的降雨截留再分配特征及修正的Gash模型在该地区的适用性,以典型的白桦林(Betula platyphylla)和云冷杉针叶混交林为研究对象,基于2017年5—9月的降雨截留观测数据,结合松江源生态站定期观测的气象数据与样地数据,分析两种林型的降雨截留再分配规律,同时采用修正的Gash模型对降雨再分配的各个过程进行模拟。结果表明:研究期间白桦林与云冷杉针叶混交林的林外降雨总量分别为217.4和393.6 mm。白桦林的穿透雨量、树干径流量均高于云冷杉林,林冠截留量低于云冷杉林。两种林型的林外降雨量与穿透雨量、树干径流量、林冠截留量、降雨强度有显著的相关性(P<0.01),利用曲线回归方程分析,二次函数可较好的说明两种林型的穿透雨与林外降雨、树干径流与林外降雨之间的相互关系,幂函数方程较好的解释了林冠截留与林外降雨的相互关系。两种林型的林冠截留总量、树干径流、穿透雨的模拟值均高于实测值,相对误差范围在3.81%～9.61%。

To explore the rainfall interception and redistribution characteristics of two forest types in Changbai Mountains and the applicability of modified Gash model,taking typical Betula platyphylla forests and spruce-fir mixed forest in Changbai Mountains as research objects,based on the rainfall interception observation data from May to September in 2017,the regularly observed meteorological and sample plot data of Songjiangyuan Forest Ecosystem Research Station were synthesized to analyze the law of rainfall interception and redistribution,and the revised Gash model was used to analyze the rainfall redistribution.The total rainfall outside the forest was 217.4 mm in B.platyphylla forest and 393.6 mm in spruce-fir coniferous forest.The throughfall and trunk runoff of Betula platyphylla forest were higher than spruce-fir forest,and the canopy interception was lower than spruce-fir forest.There were significant correlations between the rainfall of the two forest types and the penetration rainfall,trunk runoff,canopy interception and rainfall intensity(P<0.01).By using the curve regression equation,the quadratic function can explain the relationship between the penetrating rain and the rainfall outside the forest,the trunk runoff and the rainfall outside the forest,and the relationship between canopy interception and the rainfall outside the forest can be well explained by the power function equation.The simulated values of canopy interception,trunk runoff and penetrating rain of the two forest types were higher than the measured values,and the relative error ranged from 3.81%to 9.61%.