Debris flow hazard evaluation based on the GTW-ECM in Shijiaying Township, China

Debris flows are common geological disasters in mountainous areas that seriously threaten people’s lives and property safety. Debris flow hazard evaluation can provide important help for disaster prevention and effectively reduce the damage caused by debris flows. Shijiaying Township is located in a mountainous area, and local debris flows have become more active with the destruction of the ecological environment. Choosing a reasonable model to evaluate the hazards of debris flow gullies and carrying out debris flow management have become important parts of the current geological disaster research in Shijiaying. In this paper, the efficacy coefficient method based on the game-theoretic combination weighting method (GTW-ECM) is proposed to evaluate the hazard of debris flows in each gully. The GTW-ECM model is compared with the traditional evaluation models based on single weighting method and average combination weighting method. The results show that the hazards of debris flow gullies in Shijiaying are mainly medium and low, including 5 medium hazards and 5 low hazards. Only Jinjitai gully and Dongjiang gully reach high hazard grades. They should be treated as a priority, and the environmental restoration of other gullies should also be enhanced. The GTW-ECM model can effectively reduce the adverse effects of subjectivity and sample size in the evaluation process and has better accuracy and applicability. Its evaluation results are also more comprehensive, objective, and realistic. It is worth promoting and using in the evaluation of debris flow hazards.