塔克拉玛干沙漠地下水十大问题与展望:基于60年来的水文地质调查研究成果

Ten questions and visions of groundwater in the Taklimakan Desert:Based on 60-year hydrogeological investigation and research

【研究目的】系统总结近60年来塔克拉玛干沙漠地下水的调查研究成果,从地下水补给排泄、地下水水质与地下水循环等三方面总结主要的成果与认识,指出目前调查研究的不足之处和需要解决的十大问题,展望下一步的工作方向与重点任务。【研究方法】通过系统收集塔克拉玛干沙漠地下水相关的调查报告、学术论文,结合国内外其他沙漠区的最新研究成果,从地下水水量、水质及地下水循环等方面梳理调查研究进展。【研究结果】沙漠地下水的主要来源是绿洲区地下水侧向补给、降水入渗与河水入渗补给;地下水的主要排泄方式是蒸散发,还有少量的人工开采;地下水贮存量巨大,约有80多万亿m^(3);但目前补给量与排泄量的估算均有较大的不确定性。沙漠地下水的水质较差,除个别地区小于5 g/L外,大部分地区在5~10 g/L;在垂向上地下水水质具有上咸下淡的特点。地下水的区域运动规律是先从南向北流动,至塔里木河冲积平原后折向东流,地下水平均流速为55.94 m/a。【结论】下一步建议针对本文提出的十大问题,采用定量化的手段,从更长的时间尺度对地下水的补给量、排泄量进行估算;通过分层试验以及监测等技术获取更多的地下水循环信息,系统研究地下水的循环规律,提出沙漠区地下水循环的模式,定量总结各个循环系统的特点;进一步加大对沙漠区淡水寻找和高矿化地下水开发利用技术研发。

This paper is the result of hydrogeological survey engineering.[Objective]A systematic review has been conducted on groundwater investigation and research in the Taklimakan Desert over the past 60 years to consolidate significant achievements and insights regarding groundwater recharge,discharge,and circulation.The review highlights key deficiencies in current research efforts,presents ten unresolved questions,and identifies areas for future study.[Methods]Investigation reports and academic papers were meticulously gathered on groundwater in the Taklimakan Desert for a comprehensive review on groundwater quality,quantity,and circulation.This review was conducted in conjunction with the latest relevant findings on desert groundwater from both domestic and international hydrogeological communities.[Results]Groundwater in the desert primarily originates from lateral groundwater flow from oases,precipitation,and river water infiltration.It is predominantly consumed by evapotranspiration,with a limited amount withdrawn by humans.The vast groundwater storage in the region is estimated to be around 80 trillion m^(3).However,there is currently significant uncertainty in estimating groundwater recharge and discharge.The overall groundwater quality is generally poor,as evidenced by the spatial distribution of total dissolved solids(TDS),with most of the desert containing saline groundwater with TDS levels ranging from 5 to 10 g/L,while only a small area has TDS levels below 5 g/L.Vertically,the groundwater quality is characterized by saline groundwater in deeper layers and brackish groundwater in upper layers.Regionally,groundwater flows northward and then shifts eastward at the northern edge of the Tarim River fluvial plain,with an average velocity of 55.94 m/a.[Conclusions]To address these scientific questions,future studies should focus on quantifying groundwater recharge and discharge using more precise and extended methodologies.Detailed data on groundwater circulation can be obtained through packer tests and monitoring to systematically analyze circulation patterns,establish regional groundwater flow patterns,and quantitatively summarize the characteristics of each flow system.Additionally,efforts should be made to identify sources of fresh water and develop techniques for utilizing high Total Dissolved Solids(TDS)groundwater in the desert in upcoming investigations and research endeavors.