Layout Optimization Of Rural Settlements Based On Weighted Voronoi Diagram

Rural settlements is the major carrier of agricultural production and rural life.It is the focus of study on new rural construction and man-land relationship.In the vast rural areas of Dayushu town,due to the lack of long-term systematic planning and supervision,While influence of traditional concept of spontaneous selection and built-up cost,there exists a series of secondary problem such as house volume ratio that is less than 1,and newly-Buildings that occupy arable land.Because scientific and technological methods are introduced into agricultural production,the level of agricultural mechanization has been so greatly improved,that a lot of rural labor costs is saved.With the rapid development of urbanization,transfer of rural labor force leads to phenomena of the increasing per-capita residential land and rising hollow rate of villages.As a gathering place for human activities,the rational distribution not only promote the further development of rural economy and population stability,but also effectively protect arable land,Which is of great practical significance to utilization of rural land resources and sustainable development.The Sanjiang Plain is an important food production base in China,with developed agricultural production,and the rapid development of rural economy.The contradiction of agricultural production and residential layout problem are becoming more and more obvious.Through the foundation,it is of theoretical and practical significance to study spatial layout optimization in Sanjiang Plain.In this paper,68 rural settlements are selected as research object in Dayushu town of the Hinterland of Sanjiang plain.With the support of GIS technology,this paper utilizes multifarious quantitative analysis methods to explore distribution characters and layout pattern.This study proposes layout styles,and then determines layout and adjustment scheme with migratory scope and direction of migrated settlements.The major results are listed as follow:(1)By employing spatial statistics and the Weighted Voronoi Tessellation,this paper researches distribution character and current situation on rural settlements,and then obtains three layout patterns including satellite type,block type and scattered type.Per-capita rural residential land quantity exceeded,and the level of intensive utilization is low.What's more,distribution of rural settlements is comprehensively affected by town,water systems and traffic roads.(2)From four aspects including development basis,live condition,production condition and ecology condition,22 indicators are selected to construct the evaluation index system,then and calculate the Nodular index for rural settlement patches and divided into four grades.(3)On the basis of ranking results,implementing GIS spatial analysis and statistics analysis,rural settlements patches are divided into four categories: key villages,grassroots villages,migration villages and fragmentary parcels,which are respectively 13,20,22 and 13.From the perspective of remedying hollow settlements and new rural construction develop,considering current distribution of rural settlements,four kinds of layout optimization strategies are put forward including priority development,restrictive development,combined migration and stressed harness.(4)Delimited influenced scope of 13 priority development settlements based on Arc Objects9.3 version secondary program.This paper determines migratory scope and direction measured by 2500 m migration radius which is obtained from point pattern analysis and accessibility of priority development settlements with Two-step Floating Catchment Area method.Combined with migratory direction of fragmentary villages,an optimal scheme to spatial distribution adjustment for rural residential patches in Dayushu town is formulated.Through adjustment,the number of settlements from original 68 gradually evolved into 31,the total area is reduced to 860 hectares,residential density decreased to 8.09 per square kilometers,the average area increased to 25.30 hectares.