| Due to its special geological and geomorphological background,the debris flow in Dongchuan District is frequent and has great destructive power,which is the primary geological disaster causing major losses.The villages in Dongchuan District are widely distributed,and the mudslide disaster poses the greatest threat to the village.The mudslides have inundated many local village buildings,farmland and unsuspecting villagers,forcing many villages to relocate.In the long river of time,the spatial layout of the village affected by the disaster is also constantly changing.The village's disaster prevention planning is an important part of urban and rural disaster prevention and mitigation planning.From the perspective of disaster prevention planning,the distribution characteristics and laws of villages under the assessment of debris flow disaster susceptibility can not only effectively assess the susceptibility of regional debris flow disasters,but also add debris flow disaster factors to the distribution characteristics of villages,so that the distribution of villages Research makes more sense.This paper refers to the previous research and the relevant norms of debris flow susceptibility zoning,and summarizes a series of indicators according to the principle of factor selection.The indicators were screened using statistical analysis methods to determine the factors that ultimately participate in the assessment of debris flow susceptibility.Then,the information quantity value of each level of each factor is obtained by the information quantity model method,and the result of the debris flow susceptibility of Dongchuan District is obtained by the information quantity value superposition and the natural breakpoint method.Finally,the overall distribution of villages and the distribution characteristics of each town are explored from the quantitative level,and the density distribution characteristics and distribution law of each vulnerable village are analyzed by kernel density estimation method.The main conclusions of this study are as follows:(1)There are fourteen factors affecting the formation and development of debris flow in Dongchuan District.Among them,the variance of gully density is the highest,which has the greatest impact on the formation of local debris flow;(2)The study area is divided into five levels:high,micro-high,medium,micro-low and low-prone area.The proportion of the area of each le'vel of prone areas is:10%,24%,29%,23%.14%.The high-prone areas are mainly distributed in the central and northern Jinsha River basins of Dongchuan District.Among them,the central area of Tongdu Town has the largest concentration area,involving 11 administrative villages.The low-prone areas are mainly in the eastern part of Tongdu Town and Awang Town;(3)Tongdu Town has the largest number of villages in high-prone area,and Awang Town and Red Land Town have the fewest villages in high-prone District.According to the analysis of the number of villages in the towns,the eight towns are divided into four categories according to the degree of importance of disaster prevention(debris flow).Among them,Tongdu Town should be the most important.Tangdan Town,Tobuka Town,and Shekuai Township should be highly valued.;(4)Most of the villages in high-prone area are concentrated in the western part of Tongdu Town.A small number of them are gathered in Wulong Town,Shekuai Township,Yinmin Town and Tuobuka Town.The whole shows the characteristics of many gathering points and high concentration.The gathering center is most prominent in the north of the junction of Qiga Village and Nuogutian Village in Tongdu Town;(5)As the susceptibility of regional debris flows increases,the concentration of villages increases.This is due to the harsh geological environment and relatively serious soil erosion in the high-prone area,which limits the choice of settlements.It also indirectly indicates that population density and human activities play an important role in the formation of local debris flows. |
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