Study On Distribution Characteristics And Evolution Of Rural Settlements In The Extreme Earthquake Zone Of M6 Or More In Yunnan After The 18th Century

The damage caused by earthquake disasters is large,the prediction is not strong,and the instantaneous destructive power is high.In addition,the earthquake-proof and disaster-resistant infrastructure of rural settlement buildings in China is weak and the disaster prevention measures are insufficient.When a strong earthquake occurs,earthquake disasters on rural settlement buildings The huge damage caused will be unavoidable.When the earthquake caused the collapse of the original rural settlements and the destruction of the living environment,in order to allow the population to continue,often the rural settlements would abandon the principle of choosing their place of residence for the ancestors to migrate to areas not affected by the earthquake,thus changing their original distribution.Forms,the newly formed distribution characteristics of rural settlements have greatly improved their ability in earthquake prevention and disaster reduction.Therefore,studying the distribution characteristics and evolution of rural settlements in the earthquake-stricken area after the earthquake has played an important role in improving the security and stability of rural settlements in China.On the one hand,based on the elevation and slope elements,the 21 most representative earthquakes in M6 and above since the 18th century in Yunnan were selected,using the settlement number,the average patch area,and the average shape index.The distribution characteristics of rural settlements after earthquakes in the earthquake-stricken area were studied,and the distribution rules of rural settlements in the earthquake-stricken areas of Yunnan Province were summarized.The results show that:?After the earthquake,the rural settlements in the epicenter elevation are fragmented and relatively far away.The rural settlements in the elevation range of the epicenter elevation are distributed in large scale,and the rural settlements have a high degree of aggregation and small fragmentation.?The rural settlements in the extreme earthquake zone were affected by the earthquake.The rural settlements after the earthquake mainly tend to be distributed in the slope of 0-8 degrees.?After the earthquake,the complexity and irregularity of rural settlements near the epicenter elevation range were the greatest.On the other hand,based on the random aggregation dimension of fractal theory,the three earthquakes of Wuding,Lijiang and Ludian in Yunnan Province in recent years can be selected for the comparative study before and after the earthquake.The evolution of the distribution of rural settlements in the extreme earthquake zone before and after the earthquake is deeply studied.The results show that:?The number of rural settlements in the earthquake-stricken area of Yunnan Province is generally higher than that before the earthquake,and the increase range of different earthquakes is also different.It is mainly affected by the seismic treatment of village houses.If the village has been subjected to seismic treatment,the increase in rural settlements is not large.?The distribution of rural settlements in the earthquake-stricken areas of Yunnan Province is generally:after the earthquake,the distribution of rural settlements around the midpoint of the earthquake is discrete relative to the pre-earthquake,the degree of dispersion and the rural settlements before the earthquake The distribution state and the intensity of the earthquake are related.This study provides methods and suggestions for improving the earthquake-resistant and resilience of rural settlements,which is conducive to the optimization of the safety and stability of existing rural settlements,and is also conducive to guiding the future construction of rural settlements.