基于指数分析和GIS方法的垃圾填埋场地下水环境影响分析

ENVIRONMENTAL IMPACT OF LANDFILL ON GROUNDWATER QUALITY BASED ON INDEX ANALYSIS AND GIS METHOD

为合理评估垃圾填埋场的污染潜力及其对周边地下水环境的影响,以山东省某垃圾填埋场为例,采用LPI指数法和WQI指数法评估了垃圾填埋场渗滤液的污染情况和周围地下水的水质情况;利用GIS的空间分析等功能对污染影响分布进行评估;结合地下水数值模拟,以氨氮为典型特征污染物,计算分析了渗滤液污染物迁移扩散的规律。结果表明:研究区渗滤液的污染潜力较大,具有污染周围地下水的风险,目前周边地下水水质虽处于WHO和国家标准的限制内,水质状况良好,但随着渗滤液的渗漏,氨氮等污染物的污染区域会逐步扩散为羽毛状,水质将持续变差。预计到2025年,渗滤液将开始污染周边一处居民区的地下水并逐渐扩大范围,需采取相应的防渗措施对周边地下水进行防护。

To reasonably evaluate the pollution potential of the landfill site and its impact on the surrounding groundwater environment, a landfill site in Shandong Province was selected as the research object. LPI index method and WQI index method were used to evaluate the pollution situation of landfill leachate and the water quality of surrounding groundwater. At the same time, GIS spatial analysis and other functions were used to evaluate the pollution impact distribution. Using numerical simulation and ammonia nitrogen as the characteristic pollutant, the laws of pollutant migration and diffusion in leachate were calculated and analyzed. The results showed that the leachate in the study area had a large pollution potential and risk of polluting the surrounding groundwater. At present, the quality of surrounding groundwater met the requirements of WHO and China national standards, and was generally in good condition. However, with the leakage of leachate, the polluted area of ammonia nitrogen and other pollutants gradually spread into the feather shape, and the groundwater quality would continue to deteriorate. It was expected that the leachate would begin to contaminate the groundwater in the surrounding residential area and gradually expand by 2025. So it is necessary to take corresponding anti-seepage measures to protect the surrounding groundwater.