西北干旱内陆盆地地下水生态功能的探讨

Study on ecological function of groundwater in northwest arid inland basin

以准噶尔盆地南缘地下水资源开发利用为例,分析地下水变化引起的区域地下水水位下降、泉流量衰减、水质恶化、植被退化、灌区土壤次生盐渍化与盐沼化、湖泊萎缩或干枯等生态环境效应,解析西北干旱内陆盆地地下水水位埋藏、潜水矿化度、包气带岩性与结构、土壤含盐量等地下水状态变量及其生态功能,提出地下水资源评价的内容与步骤:地质生态环境野外调查、地下水系统模型、地质生态环境系统模型及面向生态的地下水资源评价方法。最后就地下水系统参数确定和评价模型运转等问题展开讨论。

Taking the exploitation and utilization of groundwater resources in the south margin region of the Junggar Basin as an example, the eco-environment effects caused by groundwater change were analyzed, such as decline of regional water table, decreasing of spring flow, water quality deterioration, secondary salinization of soils in irrigation areas, and lake shrinking or drying out. The groundwater state variables and their ecological function in northwest inland arid basin were studied, including depth of groundwater, phreatic water salinity, lithologic characteristic of the unsaturated zone and its structure, salt content in soils. The contents and procedures of groundwater resources assessment were proposed, including basin geo-ecological environment investigation, groundwater system model, geo-eeological environment model and groundwater resources assessment method based on eco-environment. Some problems about the groundwater system parameters and running of assessment model were discussed.