云南洱海东侧引水隧道地下水环境负效应探讨

Negative Effects of Diversion Tunnel Construction on Groundwater Environment near the East of Erhai Lake in Yunnan

为防止隧道施工引起地下水环境恶化,将环境负效应评价体系应用于云南洱海东侧引水隧道工程中。利用AHP层次分析法对环境负效应体系各项指标选取适宜的指标权重,对实例地质条件以及水文地质条件等的分析,并采用模糊综合评判法对洱海东侧引水隧洞工程进行地下水环境负效应评价。评价结果表明:大理某引水隧道在经过萂村段时,造成的地下水环境负效应为Ⅳ级,隧道两侧约5 000 m内将出现地下水位下降,并伴随出现一定范围的地面塌陷和岩溶塌陷,以及明显的地表水系流量减少和井泉点枯竭。研究成果可为该引水隧洞的施工及设计提供参考。

In order to prevent negative effects of tunnel construction on groundwater environment,we applied an evaluation system to a diversion tunnel project located near the east of Erhai Lake in Yunnan. On the basis of analysing the geological and hydrogeological conditions,we employed analytic hierarchy process（ AHP） and fuzzy comprehensive evaluation method to select appropriate index weight and evaluate negative effects on groundwater environment. Results show that when the tunnel goes through Hecun segment of Dali,negative effects of level IV within5 000 m on both sides of the tunnel and decline of groundwater are caused by tunnel construction. Ground subsidence,karst collapse,obvious surface flow reduction,and wellspring depletion will also take place. The research results offer reference for the construction and design of the diversion tunnel.