干旱区人工绿洲土壤盐渍化风险综合评估

Comprehensive assessment of soil salinization risk in artificial oasis in arid area

为定量描述干旱区人工绿洲土壤盐渍化风险等级及其空间分布特征。本文以甘肃省景泰川电力提灌灌区为研究对象。通过室外数据收集、室内试验及相关数据分析,选取表层土壤含盐量为生态终点,以表层土壤电导率、土壤含盐量、土壤电导率、地下水埋深、地下水矿化度、地表灌水量、年降水量、年蒸发量、海拔、坡度及土地利用类型为比较序列,引入灰色系统理论结合Pearson相关分析法、空间遥感技术及GIS技术构建了盐渍化风险灰色评估模型,对研究区土壤盐渍化风险进行了定量评估。结果表明:研究区内盐渍化风险总值F介于0.072~0.784之间,各风险等级具有明显的区域性,区域整体风险等级处于1、2级,占比55.53%。高风险区(4级与5级风险)主要集中分布在区域东部的封闭型水文地质单元内,占比28.68%。该结果可为灌区后期土壤盐渍化防控治理提供科学指导,也可为同类干旱区人工绿洲实现水土资源可持续发展提供参考依据。

In order to quantitatively describe the soil salinization risk level and spatial distribution characteristics of artificial oasis in arid area.In this paper,Jingtaichuan electric power irrigation area in Gansu Province is taken as the research object.Through the outdoor data collection,indoor test and related data analysis,the surface soil salinity is selected as the ecological end point,and the surface soil conductivity,soil salt content,soil conductivity,groundwater depth,groundwater mineralization,surface irrigation,annual precipitation,annual evaporation,altitude,slope and land use type are taken as the comparison sequence,and the grey system theory is combined with Pearson.The grey evaluation model of soil salinization risk is established by correlation analysis,spatial remote sensing technology and GIS technology,and the quantitative assessment of soil salinization risk is carried out.The results show that:the total value of Salinization Risk in the study area ranges from 0.072 to 0.784,and each risk level is obviously regional.The overall risk level of the region is in level 1 and level 2,accounting for 55.53%.High risk areas(grade 4 and grade 5)are mainly distributed in the closed hydrogeological units in the east of the region,accounting for 28.68%.The results can provide scientific guidance for the prevention and control of soil salinization in the later stage of irrigation area,and can also provide reference for the realization of sustainable development of water and soil resources in artificial oases in similar arid areas.