Risk Assessment And Division Of Forest Biological Disasters In Inner Mongolia

With the multi index comprehensive evaluation and vulnerability scoping diagram model(VSD),this paper analyzed the spatial and temporal distribution of forestry biological disaster in Inner Mongolia based on the theoretical framework of regional disaster theory and the method of risk equivalence line.From the perspective of hazard-formation factors and hazard-bearing bodies' vulnerability,we selected 16 factors affecting the occurrence and spread of forest biological disasters and established the risk assessment index system.On this basis,we built the risk assessment model in county unit and divided the level of disaster regionalization.The results are showed as follows:(1)The time-varying law of forest pests in Inner Mongolia showed an overall increase in the number of species,but the area of occurrence decreased slowly.Forestry disease were severely distributed in the east of Hulun Buir,south of Tongliao,the central and western regions of Ordos,and the northeastern part of Ulanqab;the areas with high level of forestry pests generally occurred in the southeast and southwest of Inner Mongolia.Forest rodent damage were mainly distributed in Alxa League,Ordos,Bayannur,Xilingol League and Hulunbeier.(2)The spatial distribution law of hazard-formation factors and hazard-bearing bodies' vulnerability in Inner Mongolia generally showed eastern region > western region > central region.The assessment results of hazard-formation factors and hazard-bearing bodies' vulnerability were divided into five grades.The proportion of each grade area for hazard-formation factors were 0.13%,50.53%,10.01%,23.72% and 15.61%.The high-risk areas were mainly located in Bayannaoer and Wuhai.The proportion of each grade area for hazard-bearing bodies' vulnerability were 48.35%,16.12%,17.63%?10.08% and 7.81%.The most vulnerable areas were distributed in Hulun Buir,Ordos,Tongliao and Bayannaoer.(3)The overall risk of forestry biological disasters in Inner Mongolia is generally high in the northeast,followed by the southwest,and lowest in the central region.The results of risk assessment were divided into five classes(extremely low,low,moderate,high and extremely high)based on the natural breakpoint method.The extremely high-risk class covered 40.24% of the study area;the high-risk class 15.87%;the moderate-risk class 13.06%;the low-risk class 20.49% and the extremely low-risk class 10.35%.The extremely high-risk areas were mainly distributed in Hulunbeier,Ordos Bayannur and Wuhai.The moderate-risk areas were mainly distributed in Tongliao,Ulanqab,Hohhot,and Alxa League.The low-risk areas were mainly distributed in Baotou,Xilin Gol League,Xing'an League and Chifeng.The study reveals the spatial distribution law of forestry biological disaster risk in Inner Mongolia,which could provide scientific basis for improve the risk management of forestry biological disasters,effectively carry out disaster prevention and reduction work,rationally allocate manpower,material resources and financial resources,and minimize the corresponding disaster losses.