Evaluation of Ecological Restoration Effect on Abandoned Steep Bare Rock Mine Slopes: A Case Study of Abandoned High Steep Mine Slopes in Jiangsu Province

Ecological restoration of abandoned mines with high and steep slopes is challenging due to their steepness, water scarcity, and lack of soil, and restoration effects vary with applied techniques. This study aims to assess the ecological restoration effectiveness of restored steep bare rock slopes in Jiangsu Province. The restoration status of steep bare rock slopes was assessed through field surveys, with corresponding methods for vegetation data collection and soil sample analysis subsequently selected. An evaluation system consisting of 14 evaluation indicators from 3 aspects was established using the analytic hierarchy process (AHP). Based on the on-site investigation results and test data, the evaluation criteria and evaluation intervals for the five evaluation levels of “optimum, excellent, good, medium, and poor” have been determined. After obtaining the weights of each indicator, the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) method is used to establish a normalized matrix of evaluation indicators, calculate the weighted decision matrix, and determine the ideal solution. The results showed that (1) the proportion of ecological restoration effects in the excellent–optimum, good–excellent, and medium–good was 30%, 43.3%, and 26.7%, respectively, which is consistent with the on-site investigation results; (2) the on-site investigation and evaluation results indicate that the ecological restoration effect of steep bare rock slopes is easily affected by the slope’s soil and water conservation capacity; (3) the weights of each indicator layer are slope ecosystem stability > vegetation > soil, with a maximum value of 0.443, indicating that ecosystem stability is the main factor affecting the ecological restoration effect of mines. This evaluation system is based on on-site investigations and indoor test results, and objectively and effectively evaluates the ecological restoration effect of steep bare rock slopes through qualitative evaluation and quantitative analysis. The methodology demonstrates high applicability and reliability for steep bare rock slopes, thereby serving as a valuable reference for selecting and evaluating the efficacy of ecological restoration technologies in similar environments.