旱区湿地周边盐渍化农田生态水位阈值与“水位-水量”双控技术  

Threshold value of ecological water table and dual control technology of the water table and its quantity in the salinized farmland around wetland in arid areas

作　　者：刘鹏飞[1,2,3] 张光辉 崔尚进[1,3] 刘少玉 聂振龙 LIU Pengfei;ZHANG Guanghui;CUI Shangjin;LIU Shaoyu;NIE Zhenlong(Institute of Hydrogeology and Environmental Geology,CAGS,Shijiazhuang,Hebei 050061,China;China University of Geosciences(Beijing),Beijing 100083,China;Key Laboratory of Groundwater Sciences and Engineering,Ministry of Natural Resources,Shijiazhuang,Hebei 050061,China)

机构地区：[1]中国地质科学院水文地质环境地质研究所,河北石家庄050061 [2]中国地质大学(北京),北京100083 [3]自然资源部地下水科学与工程重点实验室,河北石家庄050061

出　　处：《水文地质工程地质》2022年第5期42-51,共10页Hydrogeology & Engineering Geology

基　　金：国家重点研发计划项目(2017YFC0406100);河北省青年科学基金项目(D2021504040);中国地质调查局基本科研业务费项目(SK202215);中国地质调查局地质调查项目(DD20221752)。

摘　　要：西北旱区湿地周边农田易盐渍化,合理实时控制和降低地下水水位是实现湿地保护及其周边农田盐渍化防控“双赢”的有效途径。选取西北石羊河流域邓马营湖湿地与农田之间过渡带为示范研究区,通过分析地下水埋深变化特征及其与表层土壤盐分的协同关系,确定生态水位阈值,并基于该阈值研发了由虹吸辐射井群为支撑的地下水“水位-水量”智能双控技术,其关键点是:采用一井虹吸联通多个辐射井,用于增大弱透水层区单井涌水量,实现水位面状控制;利用电系统、信号系统和控制器集成智能控制子系统,实现地下水水位和水量的实时控制。该技术示范应用结果表明:随地下水埋深增大,农田盐渍化风险和湿地植被芦苇覆盖率均降低,农田盐渍化防控和湿地保护的地下水埋深阈值为1.9~3.0 m;每年7—8月的潜水蒸发阶段是表层土壤主要积盐时段,期间智能双控系统可将地下水埋深调控在水位阈限范围;该双控作用不仅能够控降灌溉引起的表层土壤电导率的增大幅度,而且还能有效降低表层土壤的积盐速率;相对微咸水,淡水灌溉条件下智能双控技术的淋盐和控盐效果更明显。因此,这项技术能够实现地下水水位精准调控,对旱区湿地保护及其周边农田盐渍化防控具有重要的现实意义。The farmland around wetland in the arid areas in northwest China is easily salinized.Reasonably controlling and reducing groundwater levels in real time is an effective way of protecting wetland and preventing and controlling farmland salinization.The typical demonstration zone is selected in the transitional zone of wetland and farmland near the Dengmaying Lake of the Shiyang River Basin in the arid area.The dynamic characteristics of groundwater depth and the synergic relationship between groundwater depth and salt content of topsoil are analyzed.The threshold value of the ecological water table is confirmed.The Intelligentized dual control technology of water table and its quantity is developed,which is based on groups of radial wells connected by siphons.The key points of the technology are as follows:one well collecting many radial wells by siphons is used for increasing the water yield of the well in the aquitard and contributing to control the water level in the form of a plane.The subsystem consisting of the electricity system,signal system and controllers is used to control the groundwater level and water yield in real time.Demonstration test of the key technology application is carried out and the application effect is remarkable.The results show that when the groundwater depth increases,the risk of salinization and bulrush coverage fraction in wetland decreases.The threshold value of groundwater depth for protecting wetland and preventing and controlling farmland salinization ranges from 1.9 to 3.0 m.The intelligentized regulatory system could make the groundwater depth stay in the suitable ecological range in the stage of evaporation from phreatic water in July and August of each year,when is the critical period of topsoil salification.The regulation not only can decrease the increasing amplitude of soil conductivity caused by irrigation,but also reduce the speed of topsoil salification.The effect of dissolving and controlling salt by the dual control technology of water table and its quantity is more

关 键 词：旱区 湿地周边农田 生态水位 水位-水量双控 淋盐效率 积盐速率 

分 类 号：P641[天文地球—地质矿产勘探] X173[天文地球—地质学]