Relocation Site Selection Of Immigrants In Karst Mountainous Area

Southwest mountainous area is one of the key areas of relocation of poverty alleviation in China because of its complex terrain,frequent geological disasters and weak economy.As the main object of relocation of poverty alleviation,rural residential areas are located in the current situation of frequent geological disasters and low absorption capacity of immigrants.The relocation and location matching of rural residential areas not only effectively ensures the safety of local residents' lives and property,but also provides the basis for the relocation and location of rural settlements in karst mountainous areas with frequent geological disasters,and also provides reference value for the reasonable layout of rural settlements in territorial space planning.This study takes Donglan County of Guangxi as a typical area.Firstly,the number and layout of villages to be relocated in the study area are identified based on the results of geological hazard risk zoning and migration absorption capacity grading,then,based on the absorptive capacity,combined with the principle of proximity and other factors that affect the actual operation,the paper explores the spatial matching level of the moving out and moving in places,finally,the scale and direction of migration are determined by the principle of priority of relocation in town.The main research contents and conclusions are as follows:(1)The result of geological hazard risk assessment is one of the indicators of outgoing place identification.In this study,information method is used to explore the risk zoning of geological disasters in the study area: the low-risk area accounts for the largest proportion,which is distributed in the whole county,but the geological structure of the area is not very developed,and the threat of geological disasters to the personal safety of residents is small;the second is the high-risk area,where the rock weathering is strong,human activities are frequent,and the probability of geological disasters is high;the medium risk area accounts for the smallest proportion,and the rock mass in the area is broken,and the integrity is poor,under the condition of rainfall,collapse,landslide and other geological disasters are prone to occur.The future outgoing place should be identified from the middle and high risk areas of geological disasters.(2)The result of evaluation of the ability of absorbing immigrants is one of the indicators of the location of the ingoing place and the identification of the outgoing place.Absorptive capacity refers to the level of attracting and accommodating the relocation of farmers in terms of living environment.According to the calculation,the areas of different levels of absorbing immigrants in the study area are as follows: General absorbing capacity area > higher absorbing capacity area > lower absorbing capacity area > low absorbing capacity area > high absorbing capacity area,accounting for 39.36%,21.10%,18.22%,12.34% and 8.98% of the total area of the study area in turn,combined with the spatial distribution map,it can be seen that the general absorption capacity area accounts for the largest proportion,and the distribution is scattered,while the high absorption capacity area accounts for the smallest proportion,limited by the topographic conditions and ecological factors of the study area,it is mainly distributed around the central urban area with gentle terrain and low ecological interference,and there are high-risk areas of geological disasters.In the future,the immigration absorption level should be taken into account in the identification of outgoing place and the location of ingoing place.(3)Research on the matching and optimization of resettlement.Firstly,based on the research results of geological hazard risk zoning and migration absorption classification,7 towns were identified to be involved in relocation,the results show that there are 26 villages that need to be relocated in the study area,accounting for 15.68% of the total area of the county.Secondly,through the objective environmental factor of human absorption capacity,combined with the factors affecting the actual operation,the spatial matching level of the outgoing and ingoing place is determined by TOPSIS model.The results show that the proportion of the general spatial matching interval is the largest,followed by the good spatial matching interval,the optimal interval area is the smallest,and the overall spatial matching level is general,mainly due to the terrain ecology and other aspects.Finally,adhering to the principle of priority of relocation within the town,it is clear that there are five villages in the town that can be relocated within the town,and the other two villages in the town take the way of relocation within the town and cross-border relocation,so as to meet the scale requirements of relocation site selection.