输水条件下额济纳绿洲浅层地下水水化学特征与水位埋深关系

浅层地下水水化学特征及水位埋深是干旱区地下水环境变化的重要指示, 研究其时空变化对干旱区绿洲生态环境修复及其可持续发展具有重要意义。以我国西北干旱区第二大内陆河) ) ) 黑河下游额济纳绿洲为研究区, 以2017 年 8 月水化学组分分析数据为基础, 结合水化学历史分析数据( 2001 年 9 月和 2009 年 8 月) 及地下水位埋深自动监测数据, 运用反距离权重( IDW) 插值方法和水化学 Piper 图解法, 分析了生态输水以来( 2001- 2017 年) 额济纳绿洲地下水水化学特征和水位埋深的时空变化特征及二者间的响应关系。结果表明, 在空间上, 地下水位从西南到东北逐渐降低, 地下水总溶解固体( TDS) 沿着地下水流向呈增加趋势。2001 年、2009 年及 2017 年地下水化学类型变化不明显, 分别呈 SO 4 · Cl-Mg · Na, SO4 · Cl-Na · Mg , SO4 · Cl- Na · Mg; 地下水中 TDS 变化较为明显, 即在2001 年最高, 2017 年次之, 2009 年最低。T DS 与地下水位埋深之间呈非线性统计关系, 具体表现为: 水位埋深在11 5~ 3 m 及 6 m 以下范围内, T DS 变化不大, 稳定维持在2 000 mg / L 左右; 但在 3~ 6 m 范围内, TDS 随地下水位埋深增大呈一定的增加趋势。 The chemical characteristics and water level of shallow groundwater is an important indicator of groundwater environment change in the arid area. Under standing its temporal and spatial variations are of key significance for the sustainable development in arid ecosystems. The Ejina Oasis in the lower reaches of Heihe River of the second largest inland river basin of northwestern China was selected as the study area. Based on the shallow groundwater sampling and water chemical composition analysis data of August 2017, the historical hydro-geochemistry data ( September 2001 and August 2009) and groundwater table depth automatic monitoring data, the tempo-spatial variations of shallow groundwatercs hydro-geochemistry in Ejina Oasis and the response to groundwater depth were analy zed using the Inverse Distance Weight ( IDW ) inter polation method and the Piper graphic method. The results showed that the shallow groundwater level in the Ejina Oasis gradually decreased from southwest to northeast; however, groundwatercs TDS, in contrast, gradually increased in this direction. There was no obvious change in groundwater chemical types in 2001, 2009 and 2017, and the type of water chemistry in 2001, 2009 and 2017 were SO 4 · Cl-M g · N a, SO4 · Cl-Na · M g , SO 4 · Cl-N a · M g, respectively. The change o f TDS in groundwater was more obvious, and the highest TDS was observed in 2001, followed by 2017, while the lowest was detected in 2009. A nonlinear relationship between TDS and groundwater table depth was detected. The water table depth ranged 1.5-3 m and below 6 m, TDS did not change much with a value of approximately 2 000 mg / L ; however , at 326 m, TDS increased when the groundwater table depth was getting larger. 国家自然科学基金( 41671023; 41371059; 41571029) ; 中俄( NS FC2RFBR) 项目( 41811530084; 18255253025 )