基于过程模拟的李官堡水源地地下水污染预警

Groundwater Pollution Early-warning of Liguanpu Water Source Based on Process Simulation

基于过程模拟的地下水污染预警是基于包气带和饱和带过程模拟的耦合实现的,且融合了涵盖整个地下水系统的四个预警指标。选取浑河冲洪积扇的李官堡水源地为例,基于Hydrus-1D和Visual Modflow分别进行包气带过程模拟和饱和带过程模拟,针对潜层和承压层的复杂程度分别制定了各自的预警临界值;经分析可知,随着时间的推移,地表污染物持续进入到地下水中,污染晕范围不断扩大,地下水中最大浓度值和水源井浓度值也持续增加,且承压含水层的预警级别要高于潜水含水层;同时基于潜层和承压层中污染物最大浓度值与时间分别近似呈线性关系和指数关系可进行长时间尺度的预警;并提出了零级预警区和一级预警区管理措施以监测和预防为主,二级预警区、三级预警区和四级预警区管理措施以控制和监测为主。

The process simulation of unsaturated zone and saturated zone can represent 4 early-warning factors, which cover the whole groundwater system. The process simulation of unsaturated zone combined with the process simulation of saturated zone is the method of groundwater pollution early-warning based on process simulation. This paper chose the Liguanpu water source as the study area, made process simulation of unsaturated zone saturated zone based on Hydrus-1D and Visual Modflow, and determined the critical value for early warning according to the complexity of the unconfined aquifer and confined aquifer. The results show that the contaminant plume increase with the time, and the maximum concentration of the plume and water source well also increased in both unconfined aquifer and confined aquifer. This paper proposed different critical values of early-warning for unconfined aquifer and confined aquifer, and the early-warning level of confined aquifer is higher than unconfined aquifer with the passage of time. The relationships between the maximum concentrations of unconfined aquifer and confined aquifer with time are linear and exponential, which can be used for the early-warning in the long time. This paper also proposed that monitoring and preventing will be taken as the principal thing in the management strategies for the first-level and zeroth-level early-warning areas, and controlling and monitoring be taken as the principal thing in the management strategies for the forth-level, third-level and secondlevel early-warning areas.