毛乌素沙地不同地下水位埋深下土壤水补给特征及影响因素  

Characteristics and their influencing factors of water recharge under different groundwater levels in the Mu Us Sandy Land of China

作　　者：裴艳武 黄来明[1,3] 邵明安 李荣磊[1,2] 张应龙 Pei Yanwu;Huang Laiming;Shao Ming’an;Li Ronglei;Zhang Yinglong(Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;College of Natural Resources and Environment,Northwest A&F University,Yangling 712100,China;College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Chinese Academy of Sciences,Yangling 712100,China;Shenmu Ecological Association,Shenmu 719399,China)

机构地区：[1]中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室,北京100101 [2]西北农林科技大学资源环境学院,杨凌712100 [3]中国科学院大学资源与环境学院,北京100049 [4]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,杨凌712100 [5]陕西省神木县生态协会,神木719399

出　　处：《农业工程学报》2021年第12期108-116,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(41601221);国家重点研发计划重点专项课题(2016YFC051605);中国科学院青年创新促进会会员项目(2019052);中国科学院地理科学与资源研究所秉维优秀青年人才项目(2017RC203);中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室项目(A314021402-2010)。

摘　　要：土壤水分是毛乌素沙地植被恢复与生态重建的关键因子,揭示不同地下水位(Groundwater Level,GWL)埋深下土壤水的补给与转化特征对于提高水资源利用效率和植被可持续建设具有重要意义。试验通过定期测定毛乌素沙地东南缘圪丑沟流域沙柳(GWL范围253~260 cm)、樟子松(GWL范围87~93 cm)和长柄扁桃林地(GWL范围172~176 cm)降水、土壤水及地下水δ2H和δ^(18)O,分析了不同GWL埋深下3种林地土壤水补给特征及其影响因素。结果表明:沙柳、樟子松及长柄扁桃林地土壤水δ2H和δ^(18)O均位于当地大气水线的下方,且3种林地土壤水线斜率(5.69~7.13)均小于当地大气水线斜率(7.79),表明各林地土壤水均在不同程度上受当地降水的补给。监测期间沙柳林地0~20 cm土壤水、樟子松和长柄扁桃林地0~40 cm土壤水均表现出重组分同位素贫化轻组分同位素富集的现象,且与降水同位素呈显著正相关关系(P<0.05),表明不同林地浅层土壤水(<40 cm)更易受降水补给的影响。不同林地深层土壤水(沙柳林地180 cm以下,樟子松林地60 cm以下,长柄扁桃林地120 cm以下)δ2H和δ^(18)O的均值与地下水接近,且随深度增加土壤水重组分同位素逐渐贫化并趋于稳定(变异系数<10%)。根据不同深度土壤水δ^(18)O和地下水δ^(18)O之间的相关关系,得出监测期间3种林地(沙柳、樟子松和长柄扁桃林地)地下水向上补给土壤水的深度范围分别为73~80、27~33和52~56 cm。因此,毛乌素沙地浅层地下水对深层土壤水的补给可在一定程度上缓解旱季土壤水分亏缺,为保障该区人工固沙植被生长提供潜在的水分来源。Water and soil conservation have been highly critical to the vegetation restoration and ecological reconstruction in the arid and semi-arid regions,particularly in southeastern China.Thus,it is necessary to characterize the soil water recharge and movement under different Groundwater Levels(GWL)for water use efficiency and sustainable agriculture.In this study,the hydrogen and oxygen isotopic compositions(δ2H andδ^(18)O)of rain water,soil water and groundwater were measured in three different woodlands(i.e.,Salix psammophila woodland with GWL range of 253-260 cm,Pinus sylvestris L.var.mongholica Litv.woodland with GWL range of 87-93 cm and Amygdalus pedunculata Pall.woodland with GWL range of 172-176 cm)in the Gechougou watershed in the southeastern edge of Mu Us Sandy Land.The characteristics and influencing factors of soil water recharge were clarified in three types of woodland.Results showed that theδ2H andδ^(18)O of soil water were plotted below the local meteoric water line,in Salix psammophila,Pinus sylvestris L.var.mongholica Litv.,and Amygdalus pedunculata Pall.Woodland,where the slope of soil water line in the three types of woodlands(5.69-7.13)was less than that of the local meteoric water line(7.79),indicating that the soil water in each woodland was replenished by the local precipitation.Theδ2H andδ^(18)O of soil water in Salix psammophila(0-20 cm),Pinus sylvestris L.var.mongholica Litv.(0-40 cm),and Amygdalus pedunculata Pall.Woodland(0-40 cm)exhibited the depletion of heavy isotopes and enrichment of light isotopes in monitoring period,while significantly positive correlated(P<0.05)with the hydrogen and oxygen isotopic compositions of precipitation,indicating that the shallow soil water(<40 cm)under different woodlands was more easily replenished by the precipitation.The mean values ofδ2H andδ^(18)O of deep soil water in different types of woodlands(Salix psammophila(>180 cm),Pinus sylvestris L.var.mongholica Litv.(>60 cm),and Amygdalus pedunculata Pall.Woodland(>120 cm))were close to those

关 键 词：土壤 水 稳定同位素 地下水 分布特征 毛乌素沙地 

分 类 号：S728.2[农业科学—林木遗传育种]