Impacts of water surge from mountain railroad tunnels on ecological environments based on the RSEI model

Abstract

Tunnels play a significant role in mountain railroad routes and increase the efficiency of railroad traffic. However, water surge from tunnels can seriously impact the ecological environment during the construction period. This study selected a typical mountain railroad tunnel in southwest China and used the Remote Sensing Ecological Index (RSEI) to evaluate the changes in the ecological environment along the tunnel surge water path and relate the impacts to the main influencing factors throughout the whole tunnel construction cycle. The following conclusions were obtained: (1) The RSEI from 2005 to 2020 mostly ranged within 0.25–0.75. The most severe ecological disturbances occurred in areas directly affected by tunnel construction and along the water surge path; (2) in addition to affecting the surrounding ecological environment during the construction period, tunnel surge water continued to adversely affect the environment during the post-construction period; (3) in the post-construction period, the areas 300–450 m and 750–850 m from the tunnel exit had the largest changes in RSEI. This study provides scientific evidence to support environmental planning for mountain railroad tunnel construction, which is necessary to achieve both efficient tunnel construction and environmental protection.