Research On Information Extraction And Layout Optimization Of Rural Residential Areas In Alpine-Gorge-Area

Using remote sensing and GIS technology to study the information extraction and layout optimization of rural settlements in mountainous areas is of great significance to land consolidation,precise migration of poverty alleviation,new rural construction and rural revitalization development.Based on Landsat8,Sentinel2 and GF-1 remote sensing image data,this paper uses object-oriented method to extract the rural residential areas of Dongxing Town,Maoxian County,and studies their suitability evaluation and layout optimization.The main research contents and results are as follows:(1)From the aspects of spectral features,remote sensing derived data features,texture features,geometric features and topographic features,the features of multi-source remote sensing images are studied,and the rule model is established to realize the extraction of residential area in the study area.(2)The hierarchical random sampling method,confusion matrix and Kappa coefficient are used to evaluate the accuracy of residential extraction results.It is shown that the overall accuracy of residential area extraction based on Landsat8,Sentinel2 and GF-1 remote sensing image data is 75.77%,78.01%,85.40%,respectively.The results of GF-1 remote sensing image residential areas extraction of mountainous areas are ideal.After revision,it can meet the needs of follow-up research.(3)From the aspects of topography,roads,rivers and cultivated land,the topographic position index,landscape separation index and distribution index are introduced to analyze the current distribution characteristics of rural residential areas in Dongxing Town.The results show that the topographic location index of Dongxing Town is between[0.45,2.07],during which area between 0.77 and 1.09 is the dominant area of residential distribution because of its smaller landscape separation index,larger distribution index and wider distribution area.From the analysis of road,river and village distance,the area distribution of rural residential areas in Dongxing Town decreases with the increase of distance from road and cultivated land,while the river has less influence on this.Generally speaking,the residential areas in Dongxing Town are mainly distributed in the areas with lower elevation,smaller slope and close to roads and cultivated land.But they are scattered and have poor spatial distribution.(4)Eight evaluation factors are selected from four aspects:topographic conditions,location conditions,basic public service and residential land scale,so as to establish an evaluation index system.The weight of each factor is calculated by AHP decision analysis method.Therefore,the suitability evaluation of rural residential areas has been realized.The results show that as a whole,the distribution suitability of rural settlements in Dongxing Town is the highest in the central region.The more northward and southward the suitability is,the lower the suitability is.In the area with village as unit,there are many suitable districts and various suitable grades of settlements.The most suitable distribution area,the more suitable distribution area and the basic suitable distribution area are 39479945.04 m~2,accounting for 48.38%of the total land area of Dongxing Town.In the three suitable areas,the present rural residential area is 631248.66 m~2,accounting for 94.04%of the rural residential area of Dongxing Town.For the current residential areas,The number and area of moderately suitable residential areas are the largest,with an area of 384729.49 m~2 and a proportion of 57.18%.This shows that the residents of the town has great potential for development.(5)Based on the evaluation results,this paper introduces the weighted Voronoi diagram method to study the layout optimization of rural residents in Dongxing Town.The layout of rural residential areas in Dongxing Town should focus on the key development type,with the priority development type as the main site selection area,and fully tap the potential of internal settlement type residential areas.The demolition and reorganization type should be close to the intermediate or high-level residential areas.