Potential Risk Assessments And Spatial-temporal Patterns Of Wind-blown Sand Disaster

Wind-blown sand disaster is a typical wind secondary disaster,its damage range is very wide,especially in agriculture,animal husbandry,transportation and ecological environment and other fields.In recent years,the wind-blown sand disasters in arid and semi-arid areas in northern China were getting worse and the losses were increasing with the gradual warming of the global climate and the unreasonable utilization of water and soil resources,which seriously affects the sustainable development of local social economy and ecological environment.At present,there are not only few research achievements in the assessment of wind-blown sand disasters,but also the problem of unreasonable selection of assessment data,which leads to the low accuracy of the assessment results.In view of this,based on the formation mechanism and disaster-causing characteristics of wind-blown sand disaster,combined with the basic theory of disaster science,the wind-blown sand disaster evaluation model including 14 indexes of 3 factors were established using remote sensing data and statistical data in 2000,2005,2010,2015,and 2018.And the spatial-temporal patterns on the danger of disaster-causing factors,the sensitivity of disaster-causing environment,the vulnerability disaster-bearing body,and the risk of wind-blown sand disaster were studied.At the same time,the reasons for this pattern were also analyzed.The main conclusions are as follows:(1)The spatial distribution characteristics on the danger of disaster-causing factors indicate that the highly risk areas in Xinjiang are mainly distributed in the hinterland of the Taklamakan Desert and Kumtag Desert with strong wind and abundant sand sources.The interannual variation trend shows that the risk distribution of the disaster-causing factors in the study area in recent 20 years is obviously uneven,and the increasing and decreasing regions are interlaced with each other.The significant increasing zones are mainly concentrated in Bayingolin Mongol Autonomous Prefecture,while the significant decreasing regions are mainly concentrated in Hotan,Kashgar and Atux.(2)The spatial pattern on the sensitivity of disaster-causing environment shows that the highly sensitive areas in Xinjiang are mainly concentrated in the Gobi desert zone with insufficient rainfall and sparse vegetation,while the less sensitive areas mainly located in the Tianshan Mountains region,the Tae basin,the Altai Mountains and the oasis region on the edge of Taklamakan Desert with abundant rainfall and lush vegetation.The interannual variation trend shows that the sensitivity of disaster-causing environment in the study area is generally stable in the past 20 years.The local significant increasing areas mainly located in Yutian county on the southern edge of the Taklamakan Desert and the northern edge of Changji city,while the local significant decreasing areas are mainly distributed in the southeast of Turpan.(3)Spatial distribution characteristics of the vulnerability disaster-bearing body show that the very low vulnerability is the majority in Xinjiang,the high vulnerability areas are mainly distributed near the city such as Urumqi,Karamay and Hami with developed economy,high level of urbanization,large population density as well as Shache County and Zepu County with a wide area of arable land,relatively developed agriculture.The interannual variation trend reveals that the vulnerability degree of disaster-bearing body in the study area has generally been increasing in recent 20 years.(4)The extremely high-risk areas of wind-blown sand disaster in Xinjiang can be summarized into three types: resource-based,agricultural-based and urban-based.The resource-based are mainly located in the oil field base of the desert hinterland,such Shixi,Cainan,Lunnan,Ichi Crick and Tazhong.The agricultural-based is mainly located in Luopu county,Cele county,Yutian county,Qiemo county and Yuli county with strong wind sand activity and agricultural economy.The urban-based is located in Turpan,Korla and Karamay,which are adjacent to the desert and have developed economy and high population density.In addition,the trend of interannual variation shows that the damage degree of wind-blown sand disaster in the study area in recent 20 years is generally increasing,and the trend of the southern Xinjiang is stronger than that of the northern Xinjiang and the Eastern Xinjiang.In this paper,the subjective and objective combination method is used in the assessment on the danger of disaster-causing factors,and light data and road network data are introduced into vulnerability assessment of disaster-bearing body,which improved some deficiencies,such as strong subjectivity in the traditional assessment of the danger of disaster-causing factors and reflecting poorly internal differences on the vulnerability disaster-bearing body,thus improving the accuracy of wind-blown sand disaster assessment.In addition,this paper also supplements the research results of wind-blown sand disaster assessment in the study area,which can provide guidance and reference for the regionalization of wind-blown sand disaster risk area in Xinjiang,the adjustment and optimization of land resources,and guiding disaster prevention and control countermeasures,etc.,which has great practical significance.