| 摘要: |
| 神木市是西部地区重要的能源城市，对能源的过度开发利用引发了大量地质灾害，严重阻碍着居民生产生活和城市发展建设，因此开展地质灾害风险评价研究是该地区可持续发展的必由之路。为解决多因子综合作用对评价精度的影响，根据神木市地质环境及社会经济情况选取合适的评价因子分别建立危险性和易损性评价体系，利用主成分分析（PCA）法判断、提取主成分来避免因子间相关性的干扰，计算各因子综合分值得到危险性区划图；首次将改进层次分析（AHP）-CRITIC主客观组合赋权法应用于承灾体易损性评价当中，通过该方法计算因子综合权重得到各乡镇易损指数。叠加危险区划图和易损指数图完成神木市地质灾害风险性分区，将风险区划为高、较高、中、较低和低五个等级，分别占全市面积的5.31%、7.72%、14.17%、17.08%和55.72%，表明研究区风险等级中等偏低。可为同类型地区地质灾害风险评价工作提供参考依据。 |
| 关键词: 地质灾害 主成分分析 危险性分区 组合赋权法 易损指数 黄土高原地区 |
| DOI：10.7515/JEE222051 |
| 分类号: |
| 基金项目:国家自然科学基金项目（41972292，41772323）；陕西省重点研发计划（2022ZDLSF06-03）；国家重点研发
计划（2017YFD0800501） |
| 英文基金项目:National Natural Science Foundation of China (41972292, 41772323); Key Research and Development Program of Shaanxi (2022ZDLSF06-03); National Key Research and Development Program of China (2017YFD0800501) |
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| Research on geological hazard risk assessment based on PCA and improved AHP-CRITIC method: a case study of Shenmu, Shaanxi Province |
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LI Jiahao, XIE Wanli, YAN Ming, LIU Qiqi, HE Gaorui
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1. Department of Geology, Northwest University, Xi’an 710069, China
2. State Key Laboratory of Continental Dynamics, Northwest University, Xi’an 710069, China
3. China Railway Eryuan Engineering Group Co., Ltd., Chengdu 610031, China
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| Abstract: |
| Background, aim, and scope Shenmu is an important energy city in the western region. Excessive development and utilization of energy have caused many geological disasters, seriously hindering residents’ production and life and cities’ development and construction. Therefore, conducting geological disaster risk assessment research is the only way to sustainable development in this region. However, the influence of the multi-factor comprehensive effect on assessment accuracy must be solved in the risk assessment process. Materials and methods According to the Shenmu geological environment and social and economic conditions, appropriate evaluation factors are selected to establish hazard and vulnerability. Principal Component Analysis (PCA) is used to judge and extract the principal components to correlate different factors, and the comprehensive score is calculated to obtain the hazard zoning map of each factor; the improved Analytic Hierarchy Process (AHP)-CRITIC subjective and objective combination weighting method is applied for the first time to evaluate the vulnerability of the disaster-bearing body and to calculate the comprehensive weight of factors determining the vulnerability index of each town. Results The geological risk zoning is realized by superimposing the hazard zoning map and the vulnerability index map in the study area. The risk zoning is divided into five levels: high, mid-to-high, medium, mid-to-low, and low, accounting for 5.31%, 7.72%, 14.17%, 17.08% and 55.72% of the city’s area, separately. Discussion The high and mid-to-high risk areas are distributed in the junction of river terraces and loess hills and the gully of loess hills areas. Different factors control these areas, including landform, lithology, rainfall and human engineering activities. The terrain is up and down, and the slope stability is poor; therefore, it is easy to form high-risk rocky bodies; geological disasters develop frequently, showing higher risk. The medium-risk areas are mainly located in the 1—3 km buffer zone outside the high-risk area; the upper reaching Kuye River and the middle and upper reaching Tuwei River. Its distribution characteristics are similar to high-risk areas and distributed with leaf veins, showing an obvious watershed. The mid-to-low and low risk areas are mostly located in the northwestern aeolian sand areas and other flat, open and sparsely populated areas. In addition, the economy of these areas is relatively lagging, road transportation and buildings are not dense, and the cultivated land is small; therefore, its vulnerability and hazard level are low. The evaluation results are consistent with the actual situation of the area, and the disaster point position is the same as that of a high-risk area. Conclusions The risk level of Shenmu is moderately low, with low local manifestations in the northwest and high along the river in the north, central and southeastern areas, showing a distribution of leaf veins. Recommendations and perspectives The PCA and the improved AHP-CRITIC combined weighting methods have good application effects and accurate evaluation results in geological disaster risk assessment, providing more choices and reference values for risk assessment work in other similar regions. |
| Key words: geological disaster principal component analysis (PCA) hazard zoning combination weighting
method vulnerability index Loess Plateau |
