连续变量因子分级和机器学习模型对滑坡易发性评价精度的影响

Influence of Continuous Variable Factor Classification and Machine Learning Model on the Accuracy of Landslide Susceptibility Evaluation

  • 摘要: 滑坡易发性评价建模中环境因子分级区间和机器学习模型对建模结果的影响不容忽视。为探究这两种因素对滑坡易发性评价结果的影响规律,基于主客观赋权法通过对环境因子进行赋权以构建评价指标体系,再利用地理探测器探究不同连续变量因子分级对滑坡易发性评价结果精度的影响规律,进而分别采用随机森林模型、梯度极限提升模型和遗传算法优化的神经网络模型开展滑坡易发性研究。结果表明:通过地理探测器得到的与灾害关联度最高的分区组合计算出的最大曲线下面积值为0.886,说明该方法可以得到最优的分级区间,且能有效提高易发性评价结果的精度;在易发性评价结果中,随机森林模型最优,较梯度极限提升模型和遗传算法优化的神经网络模型精度分别提高了9.7%和9.6%。基于地理探测器的环境因子最优分级区间是合理的,且随机森林模型作为滑坡易发性评价模型是高效准确的。

     

    Abstract:
    Objectives The influence of environmental factor classification interval and machine learning model on modeling results in landslide susceptibility evaluation modeling cannot be ignored. In order to explore the influence of these two factors on the evaluation results of landslide susceptibility.
    Methods The evaluation index system is constructed by weighting the environmental factors based on the subjective and objective weighting method, and then the influence of different continuous variable factor classifications on the accuracy of landslide susceptibility evaluation results is explored by using the GeoDetector. Then, the random forest model, the gradient boosting model and the neural network model optimized by genetic algorithm are used to study the landslide susceptibility.
    Results The results show that: the maximum area under curve value calculated by the partition combination with the highest correlation degree with the disaster obtained by the GeoDetector is 0.886.This finding indicates that the method can obtain the optimal classification interval and can effectively improve the accuracy of the susceptibility evaluation results. In the evaluation of susceptibility, the random forest model has been demonstrated to be the most effective, with a 9.7% and 9.6% increase over the gradient limit lifting model and the neural network model optimised by genetic algorithm, respectively.
    Conclusions The optimal classification interval of environmental factors, as determined by GeoDetector, is reasonable, and the random forest model is both efficient and accurate in its evaluation of landslide susceptibility.

     

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