灌域水资源调配对土壤盐分和地下水水化学性质的影响  

Impact of Water Resources Regulation in Irrigation Regions on Soil Salinity and Groundwater Geochemistry

作　　者：卢凤民 LU Feng-ming(Henan Provincial People’s Victory Canal Support Center,Xinxiang 453003,Henan Province,China)

机构地区：[1]河南省人民胜利渠保障中心,河南新乡453003

出　　处：《节水灌溉》2024年第11期54-61,共8页Water Saving Irrigation

基　　金：河南省水利科技攻关项目(GG202143、GG202343)。

摘　　要：灌区对我国粮食安全和农业可持续发展至关重要,且灌区水资源配置对区域生态环境调控作用意义重大,特别是华北地区地下水超采、土壤次生盐渍化问题突出,因此,以华北典型井渠结合灌域土壤盐分和地下水水质变化为研究重点,以期揭示水资源调配对灌区生态环境的影响。通过人民胜利渠灌区3 a的田间定位实验,研究了典型区域不同地下水和地表水用水比下根层土壤盐分和地下水水化学性质的动态变化特征。随着地下水地表水用水比的增加,0~20 cm表层土壤年际盐分淋洗率呈降低趋势,而20~100 cm土层土壤盐分年际盐分淋洗率呈增加的趋势,维持0~100 cm土层土壤盐分平衡的地下水地表水用水比值接近于0.379 4;土壤盐分动态变化直接影响地下水水化学性质,土壤中的盐分离子淋溶增加了地下水中总溶解性固体含量,同时降低了地下水中钠吸附比;冗余分析结果表明,地下水地表水用水比与地下水水化学性质变化密切相关,即使地下水埋深超过8 m,灌溉和降水等也会在短时间内驱动地下水化学性质的变化。华北典型井渠结合灌区适宜的地下水地表水用水比值是调节根层土壤盐分重分布和地下水碱化趋势的重要措施。Irrigation areas play a vital role in food security and sustainable agricultural development in China,and the allocation of water resources in irrigation areas plays a critical role in regulating the regional ecological environment,especially in the North China region where groundwater overexploitation and secondary soil salinization are prominent issues.Therefore,this study focusses on the characteristics of soil salinity and groundwater quality changes in North China′s typical well canal irrigation system driven by the joint allocation of surface water and groundwater,revealing the impact of water resource allocation on the ecological environment of irrigation areas.However,how different surface water and groundwater water use ratios drive the spatiotemporal changes in soil salt redistribution and groundwater hydro-chemical properties,and how to determine the appropriate surface water and groundwater water use ratio in the People’s Victory Canal irrigation district is the focus of this study.This paper presents three-year experiment investigating the changes in soil salt and groundwater geochemistry when groundwater-surface water ratio(GSR)varied from dramatically(e.g.0.228 to 0.655)in the People’s Victory Canal irrigation district.The results showed that the annual salt leaching rate from the root zone decreased linearly as the GSR increased,but there was a threshold value to be 0.3794 approximately beyond which the salt content in the root zone remained unchanged.It was found that all treatments led to a decrease in salt content in the top 0~20 cm soil,but the change in salt content in the 20-100cm subsoil depended on GSR,which leached at low GSR and accumulated at high GSR values.Salt dynamics in the soil had direct consequences on groundwater chemistry.Salt leaching from the soil increased the total dissolved ions while reducing the sodium adsorption ratio in groundwater.We also found that increasing surface water in irrigation will result in reducing soil pH,evidenced from the increased cation concen

关 键 词：人民胜利渠灌区 地下水地表水用水比 盐分淋洗率 地下水化学性质 钠吸附比 

分 类 号：S27[农业科学—农业水土工程]