持续干旱条件下江汉平原厚层黏性土土壤水分运移特征研究  

Study on Soil Moisture Transport Characteristics of Thick Layered Cohesive Soil in Jianghan Plain under Persistent Drought Conditions

作　　者：李梦茹 贡磊 王清 章昱 阮恒丰 喻望 LI Meng-Ru;GONG Lei;WANG Qing;ZHANG Yu;RUAN Heng-Feng;YU Wang(Wuhan Center,China Geological Survey(Geosciences Innovation Center of Central South China),Wuhan 430205,Hubei,China;Youjiang District Tax Bureau,Baise City,State Taxation Administration,Baise 533099,Guangxi,China)

机构地区：[1]中国地质调查局武汉地质调查中心(中南地质科技创新中心),湖北武汉430205 [2]国家税务总局百色市右江区税务局,广西百色533099

出　　处：《华南地质》2025年第1期216-228,共13页South China Geology

基　　金：中国地质调查局项目(DD20160290、DD20221777)。

摘　　要：受持续高温及干旱少雨的影响,长江流域2022年遭遇自有完整气象观测记录以来最严重的气象干旱。本次研究基于江汉平原野外试验场的气象监测数据,选取该年相较往年降雨及气温具有显著差异的8~12月作为研究时段,利用不同深度土壤含水率及基质势监测数据分析干旱条件下黏性土层水分对降雨、蒸发和地下水位变化的响应规律。结果显示:浅层土壤(0~1.4 m)的含水率和水分运移受土壤蒸发和降水入渗共同影响,干旱期间水分运动以向大气蒸发为主且长历时稳定的降雨才形成有效入渗,蒸发影响深度约为1.4 m;中层土壤(1.4~3.5 m)含水率较高且比较稳定,基本不受蒸发和监测期间降雨的影响,土壤水分以“活塞流”方式向下运移,且土壤水分下渗过程中受土层非均质的影响导致在低渗层附近出现零通量面;深层土壤(3.5~6.0 m)的含水率和水分运移与地下水位的关系密切,且随着土壤深度减小,相关性变弱且滞后时间变长。与中层土壤相比,深层土壤由于受低渗层阻渗和地下水位下降的双重影响,土壤含水率和水势梯度的变化更为剧烈。Affected by continuous high temperature and low rainfall,the Yangtze River basin had experienced the most severe meteorological drought in 2022 since the establishment of complete meteorological observation records.Based on meteorological monitoring data from field test sites,this study selected August-December of 2022 as the research period with significant differences in rainfall and temperature compared with previous years.The response of cohesive soil moisture to rainfall,evaporation and groundwater level under drought conditions was analyzed by using soil moisture content and matrix potential monitoring data at different depths.The results showed that the moisture content and water transport of shallow soil(0~1.4 m)were affected by both soil evaporation and precipitation infiltration.During drought,the water movement was dominated by evaporation,with the depth about 1.4m and the effective infiltration was only formed by long-term stable rainfall.The water content of the middle-layer soil(1.4~3.5 m)was relatively high and stable,which was basically not affected by evaporation and rainfall during the monitoring period.Soil water migrated downward in the way of"piston flow",and the zero flux surface near the low permeability layer was affected by the heterogeneity of the soil layer during the infiltration process.Water content and water transport in deep soil(3.5~6.0 m)were closely related to groundwater level,and the correlation became weaker and the lag time became longer as the soil depth decreased.Compared with the middle soil,the changes of soil moisture content and water potential gradient in deep soil were more intense due to the dual effects of low permeability layer prevention and the decrease of groundwater level.

关 键 词：厚层黏性土 干旱期 水分运移 土壤水势 含水率 江汉平原 

分 类 号：P641.69[天文地球—地质矿产勘探]