森林水文作用的流域尺度效应及其评价  

The Impacts and Evaluations of Catchment Scales on Forest Hydrology

作　　者：沙玉坤[1,2] 程根伟[1] 李卫朋[1,2] 

机构地区：[1]中国科学院水利部成都山地灾害与环境研究所山地表生过程与生态调控重点实验室,四川成都610041 [2]中国科学院大学,北京100049

出　　处：《山地学报》2013年第5期513-518,共6页Mountain Research

基　　金：国家自然科学基金项目(31070405)资助~~

摘　　要：森林植被覆盖对于地面水文过程的影响,随森林面积或流域尺度大小而不同,尺度效应的准确识别和定量评价比较困难。通过水文尺度效应的形成机理分析,对主要影响机制和变化特征进行了讨论,提出了分析评判中的主要因素,即从流域大小或森林覆被对能量平衡、潜在蒸散发、水源组成、汇流速度以及河槽调蓄能力的变化等方面来对流域尺度变化的效应大小进行评价。随着流域面积的增加,森林植被的影响降低而河槽调蓄的作用增大,流域尺度也会影响汇流的路径变化,大流域的地下水比重更大,对洪水形态和枯季径流量都有显著的影响。研究还提出基于投入产出原理的最佳森林覆被率的概念和建议比率,结果有助于区分森林本身和流域大小各自对径流特征的贡献,更加合理地评估森林水文效应。The influence of forest vegetation cover to terrestrial hydrological processes varies with the watershed size.But the accurate recognition and quantitative assessment to the scale effect are very difficult.In the paper the cause of scale effect of watershed to hydrological features is discussed,its impact mechanism and variation features are analyzed as well.The watershed size and forest distribution will change energy balance,potential evaporation,runoff components,flow＇ s velocity and channel storage capacity of a basin.These factors vary with forest area and watershed size.With the increasing of watershed size,the forest＇ s impact to hydrological processes gets lower and river channel＇ s effect becomes higher.The watershed scale will turn runways of runoff as well.The ratios of groundwater will increase and surface runoff decrease with the size increasing of watershed.This change in runoff composition may influent the flood hydrographs and low-flow discharges.The optimal forest coverage and suggested ratio have been suggested based on benefit maximum rule of ecological engineering.These results will help to identify the different effects between forest characteristics and watershed＇ s size,and can be applied to improve the estimation of forest-hydrology effects.

关 键 词：森林水文 流域尺度 影响机制 效应评价 

分 类 号：P343[天文地球—水文科学]