研究目的：隧道施工对沿线生态环境产生一定的影响，不合理的开挖及排水可能导致突水突泥灾害，也 可能造成地下水疏干、井水干枯、地表蓄水量减少等生态环境影响。为定量研究隧道排水对沿线铁路生态环 境的影响，本文以某铁路隧道为例，综合考虑施工排放地下水对地下水位变化的特点及影响半径以及地理、地 质、水文地质、隧道工程等相关因素，构造隧道地下水排放对生态环境影响综合评价的层次模型，确定生态评 价指标以及评级指标的分级标准，应用层次分析法确定评价指标体系中各指标的权重值，采用模糊层次分析 法进行隧道地下水排放对生态环境的影响评价。 研究结论：( 1)建立了地下水位下降对生态环境影响的风险评价指标，采用模糊综合评价方法对工作区 域进行生态评价，结果表明影响区域范围内生态环境综合评判值为2. 69,评价级别介于差和一般范围内，说 明隧道施工对生态环境造成一定影响；（2)从动态的角度开展了地下水位监测，得到了隧道排水对地下水位 下降的影响程度，验证了模糊综合评价结果；(3)该研究结果可为山岭隧道安全施工、控制岩溶涌水提供指 导。

Research purposes： Tunnel construction has a certain impact on the ecological environment along the line. Unreasonable excavation and drainage may cause sudden water and mud bursting，as well as groundwater drainage，dry water，surface water storage capacity reduction and others phenomena affecting the surrounding ecological environment. To quantitatively study the effect of the tunnel drainage on ecological environment，this paper takes a railway tunnel as example，considering geographical， geological， hydro - geological， and tunnel project and other relevant factors， the ecological evaluation index and grading standards are determined，as well as using Analytic Hierarchy Process to decide the weight of each index value. Finally using Fuzzy Analytic Hierarchy Process evaluates the ecological environment impact assessment on groundwater discharge. Research conclusions:(1) The risk evaluation index of the impact of the groundwater level on the ecological environment is established，and the fuzzy comprehensive evaluation method is used to evaluate the ecological environment. The results show that comprehensive evaluation index average number is 2.69， which means that groundwater seepage caused by tunnel construction and adverse impact on the ecological environment. (2 ) From the dynamic point of view， the monitoring of the groundwater level is carried out. The effect of tunnel drainage on the groundwater level decreased is revealed and the results of fuzzy comprehensive evaluation are verified. ( 3 ) The research results can provide the guidance for safe construction of mountain tunnel and the control of karat water.