焦作地区水文地质条件对浅层地下水污染的控制作用研究

通过现场调查、水质分析以及模拟污染物扩散迁移发现，受水文地质条件的控制，在焦作不同区域浅层地下水的主要污染方式不同。水文地质条件还影响着污染物在地下水系统中的分布、迁移。在山前倾斜冲洪积平原地区，主要污染方式为入渗---径流扩散，本区浅层地下水对污染敏感性较高，浅层地下水中污染物浓度高于其他地区，污染物进入地下水系统后在地下径流的控制下自西北向东南方向扩散，沿大沙河一线扩散最快；在山前交接洼地，径流---蒸发浓缩作用成为主要的污染方式，长期的蒸发浓缩作用使得该区总硬度普遍超标；黄沁河冲积平原地区，入渗---蒸发浓缩为主要的污染方式，受包气带土层特殊性质的影响，浅层地下水氟污染较严重。

Research on the Control of Hydrogeological Conditions under Shallow Groundwater Pollution in Jiaozuo Area

Through on-site surveys, water quality analysis and simulation of pollutants' diffusion and migration law, we found that by the control of hydrogeological conditions, different areas of Jiaozuo has different groundwater pollution way. Hydrogeological conditions also affect the distribution and migration of contaminants in groundwater systems. In the Piedmont inclined diluvial plain areas, the main mode of contamination is infiltration-runoff diffusion. Although the thickness of the vadose zone is greater than in other regions, due to the permeability of the vadose zone is better, precipitation is relatively abundant, contaminants easily into the aquifer with the meteoric infiltration of surface water and precipitation , resulting in this area of shallow groundwater is more sensitive to pollution, the pollutant concentrations in the shallow groundwater than other region , After entering the groundwater, contaminants diffuse from northwest to southeast under the control of groundwater runoff ,in which the diffusion along the Da sha river line is the fastest . In the Piedmont handover depression, the height of capillary rise big, speed, and located in the groundwater flow's potential exchange place, so the dominant pollution effect is runoff-evaporation and concentration effect. The long-term evaporation concentration effect makes the total hardness overweight commonly. In the alluvial plain areas of huangqin river, underground runoff is weakly ，the vertical alternation role is strongly, so the rainfall infiltration and evaporation concentration is the main way of pollution. Under the influences of special hydrogeological condition, although total fluoride content in the soil is in normal level, but the fluorine pollution in the shallow groundwater is still serious.