基于Gash修正模型的野牡丹灌丛降雨截留模拟  

Modelling Rainfall Interception of Melastoma Candidum Shrubs Using A Modified Gash Model

作　　者：刘美婷 王海龙 LIU Mei-ting;WANG Hai-long(Guangdong Research Institute of Water Resources and Hydropower,Guangzhou 510635,Guangdong Province,China;School of Civil Engineering,Sun Yat-sen University,Guangzhou 510275,Guangdong Province,China)

机构地区：[1]广东省水利水电科学研究院,广东广州510635 [2]中山大学土木工程学院,广东广州510275

出　　处：《中国农村水利水电》2024年第10期59-64,72,共7页China Rural Water and Hydropower

基　　金：国家重点研发计划项目(2021YFC3200202);国家自然科学基金项目(42171020);广东省科技厅“珠江人才计划”引进创新创业团队项目(2019ZT08G090)。

摘　　要：冠层截留是森林降雨再分配过程的重要组成部分,其量化对研究生态系统的水分平衡和养分循环具有重要意义。近年来,许多研究运用不同方法来解释这一过程,并确定不同森林植被的适用模型,但对具有复杂结构的灌丛的冠层截留研究较少。通过实地观测收集气象、降雨组分等数据,分析野牡丹灌丛降雨组成特征,应用Gash修正模型进行冠层截留的模拟及验证,并进行模型敏感性分析。结果表明,Gash修正模型能够很好地模拟野牡丹灌丛对降雨的截留过程。测得穿透雨632.6 mm、茎干流118.2 mm,计算得冠层截留141.4 mm,分别占总降雨的70.9%、13.2%和15.8%。总降雨与穿透雨、茎干流均有显著的线性相关性,表明穿透雨、茎干流随总降雨的增加而增加,而用二次函数拟合总降雨与冠层截留效果较理想(R^(2)=0.71)。对数方程能较好地解释穿透雨率、茎干流率、冠层截留率与总降雨量的相互关系。穿透雨、茎干流和冠层截留模拟分别比实测值高3.6%、低10.6%和7.3%。从模型模拟的各组成部分来看,冠层截留蒸发量占截留总量的44.4%,是截留的主要去向。敏感性分析表明:冠层郁闭度c、树干持水能力St的变化对Gash修正模型模拟冠层截留的影响最显著,而其他参数变化对该模型影响不明显。研究为湿润区结构复杂的灌丛降雨再分配研究提供了思路,有助于量化灌丛生态系统对局地水资源的影响。Canopy interception is an important part of forest rainfall redistribution and is of great significance to the study of water balance and nutrient cycle in forest ecosystems.In recent years,many studies use different methods to explain this process and determine the suitable models for different forest vegetation,but there are few studies on canopy interception of wild peony shrubs with complex structures.This study collected meteorological and rainfall data through field observation,analyzed the composition characteristics of rainfall over the Melastoma candidum shrubs,simulated and verified canopy interception using a modified Gash model,and tested the sensitivity of the model.The results showed that the modified Gash model could well simulate the rainfall interception process over the shrubs.The measured throughfall and stemflow were 632.6 mm and 118.2 mm,resulting in 141.4 mm canopy interception,accounting for 70.9%,13.2%and 15.8%of the total rainfall,respectively.Strong linear relationships were established between total rainfall and throughfall and stemflow,which indicated that they increased with the increase of total rainfall,and the quadratic function was used to fit the total rainfall and canopy interception(R^(2)=0.71).Meanwhile,a logarithmic relationship was observed between total rainfall and the ratios of its three components and the simulation of throughfall was 3.6%higher than the measured values,while stem flow and canopy interception was 10.6%and 7.3%lower than the measured values,respectively.From the various components of the model simulation,the evaporation of intercepted rainfall accounted for 44.4%of the total interception,which was the main compartment of interception.At the same time,sensitivity analysis showed that the changes of canopy density c and trunk water holding capacity St had significant influence on the simulation of canopy interception by Gash modified model compared to other parameters.

关 键 词：冠层截留 野牡丹灌丛 Gash修正模型 亚热带湿润区 

分 类 号：S162[农业科学—农业气象学]