Quantification of groundwater recharge and evapotranspiration along a semi-arid wetland transect using diurnal water table fluctuations  

作　　者：JIA Wuhui YIN Lihe ZHANG Maosheng ZHANG Xinxin ZHANG Jun TANG Xiaoping DONG Jiaqiu 

机构地区：[1]School of Water Resources and Environment,China University of Geosciences(Beijing),Beijing 100083,China [2]Xi'an Center of Geological Survey,China Geological Survey,Xi'an 710054,China [3]Institute of Disaster Prevention and Ecological Restoration,Xi'an Jiaotong University,Xi'an 710049,China [4]Chinese Academy of Geological Sciences,Beijing 100037,China

出　　处：《Journal of Arid Land》2021年第5期455-469,共15页干旱区科学（英文版）

基　　金：funded by the National Natural Science Foundation of China(41472228,41877199);the Key Laboratory of Groundwater and Ecology in Arid Regions of China Geological Survey and Innovation Capability Support Program of Shaanxi Province,China(2019TD-040)。

摘　　要：Groundwater is a vital water resource in arid and semi-arid areas.Diurnal groundwater table fluctuations are widely used to quantify rainfall recharge and groundwater evapotranspiration(ET_(g)).To assess groundwater resources for sustainable use,we estimated groundwater recharge and ET_(g) using the diurnal water table fluctuations at three sites along a section with different depths to water table(DWT)within a wetland of the Mukai Lake in the Ordos Plateau,Northwest China.The water table level was monitored at an hourly resolution using a Keller DCX-22 A data logger that measured both the total pressure and barometric pressure,so that the effect of barometric pressure could be removed.At this study site,a rapid water table response to rainfall was observed in two shallow wells(i.e.,Obs1 and Obs2),at which diurnal water table fluctuations were also observed over the study period during rainless days,indicating that the main factors influencing water table variation are rainfall and ET_(g).However,at the deep-water table site(Obs3),the groundwater level only reacted to the heaviest rainfalls and showed no diurnal variations.Groundwater recharge and ET_(g) were quantified for the entire hydrological year(June 2017–June 2018)using the water table fluctuation method and the Loheide method,respectively,with depth-dependent specific yields.The results show that the total annual groundwater recharge was approximately 207 mm,accounting for 52%of rainfall at Obs1,while groundwater recharge was approximately 250 and 21 mm at Obs2 and Obs3,accounting for 63%and 5%of rainfall,respectively.In addition,the rates of groundwater recharge were mainly determined by rainfall intensity and DWT.The daily mean ET_(g) at Obs1 and Obs2 over the study period was 4.3 and 2.5 mm,respectively,and the main determining factors were DWT and net radiation.

关 键 词：groundwater recharge groundwater evapotranspiration water table fluctuation semi-arid region Ordos Plateau 

分 类 号：P641[天文地球—地质矿产勘探]