GIS支持下的西北干旱区地下侧向径流量的计算研究——以新疆淖毛湖盆地为例

CALCULATION OF LATERAL GROUNDWATER RUNOFF BY GIS FOR THE ARID REGION OF NORTHWEST CHINA

在总结研究区各断面地下水侧向径流量常规算法的基础上,通过分析已有钻孔、物探成果,结合研究区水文地质条件确定达西公式各计算参数沿断面的空间分布特征,生成计算断面参数栅格,并基于GIS采用栅格空间叠加分析计算各计算断面上的地下水侧向径流量,结果表明前人计算结果与栅格叠加分析法计算结果大体上一致,但也存在一定差异。常规的分段计算方法,常用一个参数来表征较大尺度断面,人为因素对计算结果影响较大,基于GIS的栅格叠加分析法充分考虑了各计算参数在二维空间上的各向异性,参数选取更符合实际,结果也更为可靠,计算值可直接耦合为地下水数值模型中的二类边界(定流量边界),避免流量边界上的人为分配情况,提高模型计算精度。

Based on summarizing the traditional calculation method for groundwater lateral direction runoff in each section of the study area, determining the spatial distribution characteristics of each calculation parameter along the section by analyzing the existing drilling and geophysical results, combined with the hydrogeological conditions of the study area, generate section parameter grid,analyze and calculate lateral groundwater runoff on each calculated section according to raster overlay method, the results show that the two methods are generally consistent, but there are certain differences. The traditional calculation method using a parameter to characterize large-scale sections, human factors have a greater impact on the calculation results, the raster Overlay method fully considering the anisotropy of each calculation parameter in two-dimensional space, the parameter selection is more realistic and the result is more reliable, the results can be directly coupled to the Neumann boundary condition in the numerical model of groundwater to avoid artificial distribution on the flow boundary and improve the accuracy of model calculation.