粒子追踪迹线长度的灵敏度分析及地下水源地保护区划分--以甘河子地下水水源地为例

Sensitivity analysis of particle tracking trace length and division of groundwater source protection area--An example of Ganhezi Well Field

地下水水源地的供水安全对保障居民安全用水和保护地下水具有重要意义,合理地划分地下水水源地保护区,对水源充分利用和水质保护有着重要作用。以甘河子地下水水源地为计算背景,采用数值模拟的方式建立水源地地下水流模型,基于Morris方法,对渗透系数和有效孔隙度对粒子追踪迹线长度的影响进行局部和全局灵敏度分析。利用ArcMap,分别对根据局部、全局灵敏度计算出的粒子追踪迹线长度进行一级、二级地下水源地保护区初步划分,作为日后根据当地实际情况进行多方协调、最终确认保护区范围的基础,并分析不同分析方法、不同影响因子对保护区面积的模拟结果的影响。结果显示,全局灵敏度与局部灵敏度并非简单线性关系,并且相同条件下,有效孔隙度对于粒子追踪迹线长度和地下水源地保护区范围的影响程度均大于渗透系数。根据局部、全局灵敏度划分的一级、二级地下水源地保护区面积大小关系均为:局部灵敏度(参数为渗透系数)>全局灵敏度>局部灵敏度(参数为有效孔隙度)。

The water supply safety groundwater source area is of great significance for ensuring resident′s safe water use and protecting groundwater.Rational division of groundwater source area protection zone plays an important role in making full use of water source and water quality protection.Taking the groundwater source of Ganhezi as the calculation background,the groundwater flow model of the water source area was established by numerical simulation.Based on Morris method,the influence of permeability coefficient and effective porosity on particle tracking trace length were analyzed locally and globally.Using ArcMap,the primary and two-level groundwater source protected areas were divided for particle tracking trace lengths and calculated according to local and global sensitivity.This was the basis for multiparty coordination and final recognition of the scope of protected areas according to the local actual situation in the future.The influence of different methods and different influence factors on the simulation results of the area of the protected area were also analyzed.The results showed that the relationship between global sensitivity and local sensitivity was not a simple linear relationship,while under the same conditions,the effect of effective porosity on particle tracking trace length and protection area was greater than that of permeability coefficient.According to the local and global sensitivity,the area size relationship of primary and two groundwater source protected areas were:Local sensitivity(parameter was permeability coefficient)>Global sensitivity>Local sensitivity(parameter was effective porosity).