Multi‑geohazards susceptibility mapping based on machine learning—a case study in Jiuzhaigou, China
Juan Cao, Zhao Zhang, Jie Du, Liangliang Zhang, Yun Song, Geng Sun
[Juan Cao, Zhao Zhang, Liangliang Zhang]. State Key Laboratory of Earth Surface Processes and Resource Ecology/ MEM&MOE Key Laboratory of Environmental Change and Natural Hazards, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China.
[Jie Du]. Administration of Jiuzhaigou National Park of China, Zhangzha, China
[Yun Song]. Sichuan Geological and Mineral Bureau Regional Geological Survey Team, Chengdu, China
[Geng Sun]. China‑Croatia “Belt and Road” Joint Laboratory on Biodiversity and Ecosystem Services, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China.
Abstract: Jiuzhaigou, located in the transitional area between the Qinghai–Tibet Plateau and the Sichuan Basin, is highly prone to geological hazards (e.g., rock fall, landslide, and debris flow). High-performance-based hazard prediction models, therefore, are urgently required to prevent related hazards and manage potential emergencies. Current researches mainly focus on susceptibility of single hazard but ignore that different types of geological hazards might occur simultaneously under a complex environment. Here, we firstly built a multi-geohazard inventory from 2000 to 2015 based on a geographical information system and used satellite data in Google earth and then chose twelve conditioning factors and three machine learning methods—random forest, support vector machine, and extreme gradient boosting (XGBoost)—to generate rock fall, landslide, and debris flow susceptibility maps. The results show that debris flow models presented the best prediction capabilities [area under the receiver operating characteristic curve (AUC 0.95)], followed by rock fall (AUC 0.94) and landslide (AUC 0.85). Additionally, XGBoost outperformed the other two methods with the highest AUC of 0.93. All three methods with AUC values larger than 0.84 suggest that these models have fairly good performance to assess geological hazards susceptibility. Finally, evolution index was constructed based on a joint probability of these three hazard models to predict the evolution tendency of 35 unstable slopes in Jiuzhaigou. The results show that these unstable slopes are likely to evolve into debris flows with a probability of 46%, followed by landslides (43%) and rock falls (29%). Higher susceptibility areas for geohazards were mainly located in the southeast and middle of Jiuzhaigou, implying geo-hazards prevention and mitigation measures should be taken there in near future.
Published in Natural Hazards, 2020 https://doi.org/10.1007/s11069-020-03927-8
