基于多策略优化的滑坡易发性评价——以伊犁河谷滑坡群为例

    LANDSLIDE SUSCEPTIBILITY EVALUATION BASED ON MULTI-STRATEGY OPTIMIZATION—A CASE STUDY OF LANDSLIDE COMPLEXES IN THE ILI RIVER VALLEY

    • 摘要: 在滑坡易发性评价中,样本及模型的选取优化是关系预测结果质量的重点。针对现有滑坡易发性评价,大都从样本选取到评价模型中的某单一环节进行改善,不能确保评价结果的应用质量问题。本文以伊犁河谷滑坡群为例,拟提出从滑坡-非滑坡样本筛选、评价因子体系构建、超参数寻优等3个方面进行评价的多策略优化方法。以广泛应用的随机森林(RF)、反向传播神经网络(BPNN)作为基本评价模型,结合贝叶斯算法(BO)及差分优化(DE)。从易发性等级分区图、分区统计、模型精度评价3个方面对比分析两种未优化模型(RF、BPNN)及4种优化预测模型(DE-RF、B0-RF、DE-BPNN、BO-BPNN)在滑坡易发性评价方面的表现。优化模型预测精度均有一定程度的提高,RF模型较BPNN模型在滑坡易发性评价上具有更高的预测性能,DE算法较BO算法优化效果更加明显。综合评价数据,DE-RF模型预测结果呈现更明显的规律性及更高的预测精度,极低至高易发区面积占比依次为39.14%、22.62%、21.54%、16.70%,精度4项评价指标分别高达85.4%、82.4%、89.9%、0.933。通过实地调查,实际滑坡情况与得到的滑坡易发性等级评价结果相符合,验证了本文多策略优化评价方法的有效性,可为该地区滑坡灾害预测及防灾减灾提供参考。

       

      Abstract: In landslide susceptibility assessment, optimizing both sample selection and model configuration is critical for prediction quality. Existing studies often focus on improving only a single aspect—either sample selection or the evaluation model—which may not ensure the overall reliability of the results. Taking the Ili River Valley landslide group as a case study, this paper proposes a multi-strategy optimization approach that integrates three aspects: landslide/non-landslide sample screening, evaluation factor system construction, and hyper-parameter tuning. Using the widely applied random forest(RF)and back-propagation neural network(BPNN)as base models, we combined Bayesian optimization(BO)and differential evolution(DE)to compare the performance of two unoptimized models(RF, BPNN)and four optimized models(DE-RF, BO-RF, DE-BPNN, BO-BPNN). The comparison was based on susceptibility zoning maps, zonal statistics, and model accuracy metrics. The results show that the optimized models achieve improved prediction accuracy. The RF model generally outperforms the BPNN model in landslide susceptibility prediction, and the DE algorithm delivers stronger optimization effects than BO. Based on comprehensive evaluation metrics, the DE-RF model produces more regular and accurate predictions. The proportions of extremely low, low, moderate, and high susceptibility zones are 39.14%, 22.62%, 21.54%, and 16.70%, respectively. The corresponding evaluation accuracies reach 85.4%, 82.4%, 89.9%, and an AUC of 0.933. Field investigations confirm that the actual landslide distribution aligns well with the predicted susceptibility levels, validating the effectiveness of the proposed multi-strategy optimization method and providing a reference for landslide prediction and mitigation in the region.

       

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