ISSN 1003-8035 CN 11-2852/P

    基于不同统计模型的肯尼亚滑坡危险性评价

    Assessment of landslide hazard risk in Kenya based on different statistical models

    • 摘要: 肯尼亚是我国“一带一路”倡议在东非重要支点。受高原裂谷地形和显著的雨旱季节影响,肯尼亚地质灾害频发。本文以肯尼亚的历史滑坡数据为样本,选取高度、坡度、坡向、地貌、平面曲率、土壤类型、年平均降雨量、水流强度指数、地形湿度指数及土地利用类型作为评价指标,分别基于信息量模型(IV)、逻辑回归模型(LR)和极限学习机模型(ELM)对肯尼亚滑坡灾害进行危险性区划,其中ELM分别考虑了sigmoid 函数、正弦函数和对称阈值型传输函数作为激活函数进行讨论。主要结论如下:(1)肯尼亚滑坡灾害高危险性及以上等级区域集中分布在西南部的高原和高原—裂谷过渡地带;(2)采用ROC曲线对模型精度进行评价,各模型的AUC值分别为0.977(IV)、0.965(LR)、0.859(ELM-SIG)、0.900(ELM-SIN)、0.941(ELM-HARDLIM),评价结果有效;(3)综合PR曲线结果判定,LR模型的召回率和精确率都处于较高的水平,优于其他模型;(4)肯尼亚内罗毕省(Nairobi)、中部省(Central)、尼扬扎省(Nyanza)和西部省(Western)四个省份高危险性区域占比较大。

       

      Abstract: Kenya is an important fulcrum of China's Belt and Road initiative in east Africa. However, due to its plateau rift terrain and aboriginal rain and drought season, geological disasters occur frequently in Kenya. The study used historical landslide data in Kenya as samples and selected several evaluation indexes, including elevation, slope, aspect, landform, plane curvature, soil type, annual average rainfall, stream power index, terrain witness index, and land use type. The landslide risk in Kenya was evaluated based on the information value model (IV), logistic regression model (LR), and extreme learning machine model (ELM), with the ELM model considering SIG, SIN, and HARDLIM functions as activation functions for discussion. The main findings are as follows: (1) The high-risk and above-grade areas of landslide disasters in Kenya are mainly concentrated in the plateau and plateau-rift transition zone in the southwest. (2) The ROC curve was used to evaluate the accuracy of the models, and the AUC values of the 0.977(IV), 0.965(LR), 0.859(ELM-SIG), 0.900(ELM-SIN), and 0.941(ELM-HARDLIM) models illustrate their validity. (3) Considering the PR curve results comprehensively, the recall rate and precision rate of the LR model are at a high level, marking it better than other models. (4) Nairobi, Central, Nyanza and Western provinces in Kenya account for a significant proportion of the high-risk and above-grade areas of landslide disasters.

       

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