Influence of canopy and topographic position on soil moisture response to rainfall in a hilly catchment of Three Gorges Reservoir Area,China  

植被冠层和坡位对长江三峡山地小流域降雨过程土壤水分响应的影响

作　　者：LIU Muxing WANG Qiuyue GUO Li Yl Jun LIN Henry ZHU Qing FAN Bihang ZHANG Hailin 刘目兴;王秋月;郭立;易军;林杭生;朱青;范碧航;张海林(College of Urban and Environmental Sciences,Central China Normal University,Wuhan 430079,China;Department of Ecosystem Science and Management,Pennsylvania State University,University Park,PA 16802,USA;State Key Laboratory of Lake Science and Environment,Nanjing Institute of Geography and Limnology.CAS,Nanjing 210008,China)

机构地区：[1]College of Urban and Environmental Sciences,Central China Normal University,Wuhan 430079,China [2]Department of Ecosystem Science and Management,Pennsylvania State University,University Park,PA 16802,USA [3]State Key Laboratory of Lake Science and Environment,Nanjing Institute of Geography and Limnology.CAS,Nanjing 210008,China

出　　处：《Journal of Geographical Sciences》2020年第6期949-968,共20页地理学报（英文版）

基　　金：National Natural Science Foundation of China,No.41771261,No.41601215;Hubei Province Natural Science Foundation of China,No.2015CFA141,No.2016CFA027,No.2019CFB766;Fundamental Research Funds for the Central Universities,No.CCNUI8QN002,No.CCNUI9TS001。

摘　　要：Rainfall provides essential water resource for vegetation growth and acts as driving force for hydrologic process,bedrock weathering and nutrient cycle in the steep hilly catchment.But the effects of rainfall features,vegetation types,topography,and also their interactions on soil water movement and soil moisture dynamics are inadequately quantified.During the coupled wet and dry periods of the year 2018 to 2019,time-series soil moisture was monitored with 5-min interval resolution in a hilly catchment of the Three Gorges Reservoir Area in China.Three hillslopes covered with evergreen forest(EG),secondary deciduous forest mixed with shrubs(SDFS)and deforested pasture(DP)were selected,and two monitoring sites with five detected depths were established at upslope and downslope position,respectively.Several parameters expressing soil moisture response to rainfall event were evaluated,including wetting depth,cumulative rainfall amount and lag time before initial response,maximum increase of soil water storage,and transform ratio of rainwater to soil water.The results indicated that rainfall amount is the dominant rainfall variable controlling soil moisture response to rainfall event.No soil moisture response occurred when rainfall amounts was<8 mm,and all the deepest monitoring sensors detected soil moisture increase when total rainfall amounts was>30 mm.In the wet period,the cumulative rainfall amount to trigger surface soil moisture response in EG-up site was significantly higher than in other five sites.However,no significant difference in cumulative rainfall amount to trigger soil moisture response was observed among all study sites in dry period.Vegetation canopy interception reduced the transform ratio of rainwater to soil water,with a higher reduction in vegetation growth period than in other period.Also,interception of vegetation canopy resulted in a larger accumulated rainfall amount and a longer lag time for initiating soil moisture response to rainfall.Generally,average cumulative rainfall amount for initi

关 键 词：INTERCEPTION infiltration lateral flow soil water storage forest PASTURE 

分 类 号：S152.7[农业科学—土壤学]