Ecological Risk Assessment Of Debris Flow Disaster In Yanbian Prefecture

Ecological risk assessment can assess the impact of a geological disaster on the ecosystem and help environmental management departments understand the relationship between ecological impact factors and ecological consequences.The frequent occurrence of debris flow disasters in Yanbian Korean Autonomous Prefecture(hereinafter referred to as "Yanbian Prefecture")poses a huge threat to the life and property security of the local people and the ecosystem.This paper takes debris flow disaster as the risk source,and constructs the ecological risk assessment of debris flow disaster in Yanbian Prefecture from three dimensions of disaster risk,ecological vulnerability and potential ecological loss,so as to provide scientific guidance for the ecological risk prevention work in the research area.In this study,9 influencing factors are selected to build debris flow hazard evaluation index,and 2 evaluation models are selected to evaluate the hazard of debris flow hazard in Yanbian Prefecture.The results show that the proportion of disaster points and area in the fifth level hazard area calculated by the artificial BP neural network model is 72%,the proportion of disaster points and area in the fifth level hazard area calculated by the information quantity model is 64%,and the prediction accuracy of the artificial BP neural network model is higher.The main factors influencing the debris flow disaster in Yanbian are river,elevation and slope.The areas with high risk of debris flow disaster in Yanbian Prefecture are the north of Antu County,the west of Wangqing County,the north of Dunhua City,the south of Dunhua City,the east of Helong City,the north of Tumen City and the middle of Hunchun city.Yanbian ecosystem is divided into forest,paddy field,dry land,grassland,water area,residential area and other seven ecosystems.Landscape pattern index is selected to evaluate the ecological vulnerability of Yanbian.The results showed that the vulnerability indexes of each ecosystem in Yanbian were:Forest 0.193,grassland 0.708,paddy field 0.533,dry land 0.733,residential area 0.760,water area 0.655,other 0.469.The vulnerability of forest ecosystem is low,and that of residential area and dry land ecosystem is high.The areas with high ecosystem vulnerability in Yanbian Prefecture are mainly the middle of Dunhua City,the east of Yanji City,the south of Hunchun City,the north of Longjing City and the middle of Antu County.NPP,soil conservation service and biodiversity were selected to construct the potential ecological loss of Yanbian.The potential ecological loss of Yanbian was obtained and classified by adding equal weight of each evaluation index layer after normalization.The results show that the areas with high potential ecological loss are mainly located in the northwest of Dunhua City,the southeast of Hunchun City,and the junction of Helong city and Longjing City.The areas with low potential ecological loss are mainly located in the middle of Dunhua City,the northeast of Wangqing County and some areas at the junction of Longjing City and Yanji city.Most of the other areas belong to the area of medium potential ecological loss.Using GIS technology to multiply the three kinds of evaluation and classify them,the ecological risk zoning map of debris flow disaster in Yanbian Prefecture is obtained.The results show that the high ecological risk areas of Yanbian Prefecture are mainly distributed in the middle of Dunhua City,the middle of Antu County,the south of Wangqing County,the north of Wangqing County,the south of Hunchun City,the north of Helong city and the north of Longjing City.The risk structure of high ecological risk area is mainly high risk high vulnerability high loss,high risk high vulnerability low loss,low risk high vulnerability low loss structure.