蒸发条件下地下水埋深对土壤水盐含量的影响  

Effect of groundwater depth on soil water and salt content under evaporation

作　　者：李文昊[1] 王振华[1] 王凯飞 LI Wenhao;WANG Zhenhua;WANG Kaifei(College of Water&Architectural Engineering/Key Laboratory of Modern Water-Saving Irrigation of Xinjiang Production&Construction Group,Shihezi University,Shihezi,Xinjiang 832003,China)

机构地区：[1]石河子大学水利建筑工程学院/石河子大学现代节水灌溉兵团重点实验室,新疆石河子832003

出　　处：《石河子大学学报（自然科学版）》2020年第4期443-448,共6页Journal of Shihezi University(Natural Science)

基　　金：国家自然科学基金项目(51869028,51869027)。

摘　　要：为了研究绿洲盐碱地区地下水位埋深对土壤盐碱化的影响机理。本文通过土柱试验,设置4组地下水埋深处理(30、40、50、60 cm),研究不同处理湿润锋、土壤含水率及电导率变化差异。结果表明:随着地下水埋深的增加,湿润锋的完全推进时间逐渐延长,即当地下水埋深为30、40、50、60 cm时,湿润锋完全推进分别需要60、90、130、200 h;随蒸发时间的延长,受土壤基质势等综合影响,湿润锋推进速率呈现先减后增的变化趋势。蒸发初期土壤含水量随地下水位埋深的降低而减小;随着蒸发时间的延长,由于土壤含水量与土水势的密切关系,浅层土壤含水量并不随地下水埋深呈现绝对的负相关性。持续的稳定蒸发条件下,盐分与水分共同运动;盐分随着毛管水的上升而运移;随蒸发时间延长,表层水分蒸发散失,盐分开始在土表积累。因此,地下水位埋深是造成土壤次生盐渍化的重要因素,同时持续的蒸发作用是土壤盐碱化的重要条件,水分是土壤次生盐碱化的重要媒介。In order to study the influence mechanism of groundwater table depth on soil salinization in the saline-alkali region of oasis.In this paper,through soil column test,four groups of different groundwater depth(30,40,50,60 cm)were set up for burial depth treatment to study the variation of soil moisture content and conductivity in different treatments of wet front.The results showed that with the increase of groundwater depth,the full propulsion time of the wetting front was gradually extended,when the depth of groundwater was 30,40,50,60 cm,the full propulsion time of the wetting front took 60,90,130,200 hours,respectively.With the extension of evaporation time and the comprehensive influence of soil matrix potential,the propulsion rate of wetting front decreased at first and then increased.At the beginning of evaporation,the soil moisture content decreased with the decrease of groundwater level depth,as the evaporation time lengthened,because of the close relationship between soil moisture content and soil water potential,the shallow soil moisture content didn’t show absolute negative correlation with the depth of groundwater.Under the condition of continuous and stable evaporation,salt and water moved together,and salt migrated with the rise of capillary water.With the extension of evaporation time,surface water evaporated and salt began to accumulate in the surface layer.The buried depth of underground water was an important factor of soil secondary salinization,the continuous evaporation was an important condition of soil salinization,and water was an important medium of soil secondary salinization.

关 键 词：地下水埋深 湿润锋 含水量 电导率 蒸发条件 

分 类 号：S275[农业科学—农业水土工程]