Evaluation of comprehensive treatment effect of geotechnical and ecological engineering for debris flow: case of Wenchuan County, Sichuan Province

As a crucial link in debris flow disaster control, control engineering can be divided into geotechnical engineering and ecological engineering. Geotechnical engineering is less affected by climate and can play an immediate role in the treatment of debris flow in a short time. Ecological engineering has obvious regulating effect on surface runoff and erosion. Furthermore, there are few discussions on comprehensive treatment effect between geotechnical engineering and ecological engineering for debris flow. Therefore, taking the debris flow gullies with control engineering implemented in Wenchuan area of Sichuan Province as the research object, this paper puts forward an evaluation method of treatment effect comprehensively considering the geotechnical engineering and ecological engineering. It is mainly based on the impact of engineering on the formation conditions of debris flow and the damage of projects. The comprehensive treatment effect of geotechnical and ecological engineering for debris flow is analyzed. The corresponding evaluation indexes are extracted, including 5 first-class evaluation indexes such as landform factor and water source factor, as well as 11 s-class evaluation indexes such as the peak flow reduction rate, the sediment retention ratio and the LAI ratio. The Fuzzy-AHP method is used to establish the evaluation model of treatment effect. The evaluation results are graded. It is considered that the treatment effect of other debris flow gullies is medium or above except that two gullies are poor. The evaluation results are consistent with the actual investigation, which provides a reference for the control of debris flow in this area.