Abstract The impact of tunnel drainage on local water resources has attracted increasing attention in the past decades. The potential impacts of tunnel drainage on terrestrial vegetation have been evaluated from a groundwater environment perspective. However, previous attempts did not consider the atmospheric and climatic conditions along with the change to the regional groundwater table. To address the lack of atmospheric influence, this study proposes a vulnerability assessment method focused on the soil-plant-atmosphere continuum by taking tunnel drainage, atmospheric and climatic impacts into account. The proposed method consists of five stages: (1) groundwater seepage model for water table distribution, (2) topsoil model based on a single column perspective for soil water pressure distributions, (3) dynamic root-zone wilting for the transient model, (4) Budyko-type analysis for the soil water storage under longer-term climatic changes, and (5) summary based on the outcomes of vulnerability analysis. The case study was located in the Yuexi county (Anhui, East China) and was investigated based on different soil textures, weather conditions, and groundwater table drawdown scenarios. Transient intra-annual water pressure dynamics were simulated for one year, and aggregate variations of soil water storage were summarized using the Budyko framework. The assessment method demonstrated that the textural differences and climatic changes are more impactful on plant vulnerability compared to the drainage effect in the specific case. The increase in aridity towards the sub-humid dry climate drives the soil columns to decrease the water storage, where the significant loss of water storage was also observed in the Budyko-type framework. The outcomes suggest that under sub-humid dry conditions when combined with tunnel drainage, the drawdown on shallow groundwater levels leads the vegetation to be vulnerable.

中文翻译：

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一种评估不同大气和气候条件下隧道排水对陆地植被影响的脆弱性评估方法

摘要 在过去的几十年里，隧道排水对当地水资源的影响越来越受到关注。从地下水环境的角度评估了隧道排水对陆地植被的潜在影响。然而，之前的尝试没有考虑大气和气候条件以及区域地下水位的变化。为了解决缺乏大气影响的问题，本研究提出了一种将隧道排水、大气和气候影响考虑在内的以土壤-植物-大气连续体为重点的脆弱性评估方法。所提出的方法包括五个阶段：（1）地下水位分布的地下水渗流模型，（2）基于土壤水压力分布的单柱透视表土模型，(3) 瞬态模型的动态根区萎蔫，(4) 长期气候变化下土壤蓄水的Budyko 型分析，以及(5) 基于脆弱性分析结果的总结。案例研究位于岳西县（安徽省，华东地区），并根据不同的土壤质地、天气条件和地下水位下降情况进行了调查。模拟了一年的瞬态年内水压动态，并使用 Budyko 框架总结了土壤蓄水量的聚合变化。评估方法表明，在特定情况下，与排水效应相比，质地差异和气候变化对植物脆弱性的影响更大。亚湿润干旱气候的干旱增加促使土柱减少蓄水量，在 Budyko 型框架中也观察到蓄水量的显着损失。结果表明，在半湿润干燥条件下，结合隧道排水，浅层地下水位的下降导致植被变得脆弱。