The risk of landsliding relating to mining activities in Tương Dương area, Nghệ An province

Nguyễn Thị Ḥa, Trịnh Thành, Nguyễn Phương, Nguyễn Quốc Phi

Currently, mining activities together with climate change cause heavy rainfall and geohazards, especially landslide of soil and rock debris. The field survey results in Tuong Duong area, Nghe An province show that the main types of landslide related to mineral exploitation are landsliding of the exploitation slopes, disposal sites as well as reservoirs of ore tailling. This paper used the Bayes Statistic Modeling and the Certainty Factor methods to calculate the parameters for each factor affecting landslide hazard due to mining activities. The result of integrating the calculated parameters from 14 layers of information on the geological conditions (lithology, fault, engineering geology, hydrogeology, weathered crust, soil type, etc.) as well as natural and human conditions (slope angle, slope direction, hydrological network, current land use/vegetation cover, average annual precipitation, etc.) allowed to establish the map of landslide risk prediction. The research results show that the Bayes Statistic Model and the Certainty Factor methods have high accuracy of 89.7% and 91.0%, respectively. Futhermore, this study results indicated that the southern and southwestern parts of the study area were identified as places where risk factors associated with landslides have been highly concentrated. Comparing the research results with the field observation that over 70% of the known landslide sites are in the area of high landsliding risk.

Keywords: Risk of landsliding, mining activities, Tương Dương, Nghệ An.