贡嘎山枯落物降雨截留试验及其水文效应

Study on Litter Rainfall Interception Test and Hydrological Effect in Gongga Mountain

选用贡嘎山东坡成熟针叶林、未成熟针叶林、针阔混交林和常绿阔叶林4种林下枯落物进行人工降雨试验,研究1~80 m^2尺度下枯落物对降雨的截留能力及其影响因素,分析其截留过程的水文效应特征。研究发现,各枯落物截留量在不同面积尺度下随试验面积S的增大呈递增趋势;单位面积截留率r随试验面积S的增大呈指数递减趋势;枯落物截留降雨产生的迟滞效应有利于森林水土保持。在分析枯落物天然含水率、截留能力与面积尺度关系的基础上,提出了适用于贡嘎山东坡枯落物对降雨的优化截留模型。

The study carried out artificial rainfall experiments on the four litter forests,including mature coniferous forest,immature conifer-ous forest,mixed coniferous forest and evergreen broad-leaved forest. The purpose of the experiment was to study the interception ability of litter and its influencing factors under different hydrological scales （ 1-80 m^2）. The results show that the different vegetation litter intercep-tion has an increasing trend with the increase of area while litter interception rate has a decreasing trend with the increase of area. The litter lag caused by the hysteresis will effect on rainfall interception time for soil and ＂water conservation. The litter lag caused by the hysteresis effect will benefit for soil and water conservation and infiltration recharge of groundwater. Based on the analysis of the relationships between the natural moisture content,the interception capacity and the area scale,this paper put forward an optimal interception model suitable forthe rainfall interception in Gongga Mountain.