Study on the impact of engineering construction on environmental risk assessment in alpine canyon area: a case study of Chaya County, Xizang

As one of the regions with frequent engineering construction and frequent geological disasters, the alpine gorge area of the Qinghai-Xizang Plateau is of great significance for its environmental risk assessment. This paper takes Chaya County in the region as the research object, combined with the essential data survey, using remote sensing images and a geographic information system (GIS) platform to carry out spatial statistics and analyze common geological disasters in the study area. Based on this, the SMOTE-Tomek-random forest (STRF) geological disaster evaluation model and the information method model were used to explore the impact of engineering construction on the susceptibility and vulnerability of geological disasters in the Alpine Canyon area. The results show that small geological disasters are mainly distributed in the study area, accounting for 67.95%; the vulnerability zoning of geological disasters in the study area is mainly low vulnerability area and low vulnerability area. Among them, the high vulnerability area accounts for 3.2%, and the high vulnerability area accounts for 9.86%. From the perspective of administrative regions, the vulnerability values of Yanduo Town, Xiangdui Town, and Jitang Town are higher, which is consistent with the distribution law regarding hidden danger points of geological disasters. Based on the STRF susceptibility model and the traditional random forest susceptibility model, the AUC values are all above 0.9. In the test set and training set, the accuracy of the STRF model is slightly reduced. However, the interpretability of the address disaster model in the Alpine Gorge area is enhanced. The region's susceptibility area is the highest, accounting for 50.59, 46.96, and 38.74%, respectively. The project's construction has increased the geological disaster-prone areas in the study area by 183.21 and 38.9 km², respectively. The results show that the STRF model is feasible in assessing geological disaster susceptibility in the Alpine Canyon area.