Study On Spatial Structure Characteristics Of Traditional Rural Settlement In Chengdu Plain

Under the background of rapid urbanization,the traditional rural settlements in the Chengdu Plain are declining,and their protection and development are under tremendous pressure.Quantitative study of the spatial structure characteristics of traditional rural settlements is conducive to exploring the spatial composition of traditional rural settlements and providing a scientific basis for the protection and renewal of traditional rural settlements.This paper takes the traditional rural settlements in the Chengdu Plain as the research object,and uses the statistical method of stepwise discriminant analysis to screen 30 qualified traditional rural settlements.Through aerial photography,field research and other methods,the basic data of sample settlements were collected.Based on the theory of system theory,human settlements,fractal geometry and graph relationship,qualitative methods and quantitative analysis were used to separate settlement systems and clusters.The spatial structure characteristics of traditional rural settlements under three spatial scales of system and settlement basic unit are analyzed.The results show that:(1)At the scale of the settlement system: through the combination of field research and qualitative analysis,it is found that the spatial structure of the traditional rural settlements in the Chengdu Plain has two spatial structure relationships: internal hierarchical structure and network architecture,which are hierarchical and integral.(2)Under the scale of the settlement subsystem: using the plane quantitative analysis method to quantitatively analyze the spatial form of the sample settlement,the spatial structure of the traditional rural settlements in the Chengdu Plain can be quantified into three spatial forms: cluster,finger and strip.Among them,there are 7 traditional rural settlements in the form of cluster-like space structure,21 traditional rural settlements in the form of finger-shaped spatial structure,and 2 traditional rural settlements in the form of strip-shaped spatial structure.(3)Under the basic composition unit of the settlement: the spatial structure of the traditional rural settlements in the Chengdu Plain is characterized by “large dispersion and small settlement”.Several basic units can form a settlement subsystem with different spatial structure forms.These units can be roughly divided into 10 different scales,10 households to 25 households,25 households to 50 households,and 50 households with different scales.The number of basic units of various scales is proportional to the difference between finger-shaped settlements > clustered settlements > banded settlements.Through the chi-square test,the difference in the number of units of different scales under the three spatial structures does not have statistically significant differences.In terms of spatial distribution,ArcGIS10.2 software was used to analyze the nearest neighbors of the basic constituent elements in the settlement.The average nearest neighbor index(ANN)of most sample clusters was greater than 1,indicating that the basic constituent elements of the settlement were statistically significant.Significant discrete distribution over.In terms of spatial agglomeration,GeoDa software is used to perform global autocorrelation analysis on the spatial agglomeration of basic units and main roads and river canals.The calculation results show that the Molan index of the basic unit and the main roads and river canals are mostly less than 0.3,which is extremely weak.The degree of correlation and the degree of spatial agglomeration of river canals are higher than that of roads,indicating that the basic constituent units of settlements are more spatially inclined to think of river canal clusters.In general,the basic constituent units of the traditional rural settlements in the Chengdu Plain show a discrete distribution of “point-point” regularity and a significant spatial correlation of “point-line”.(4)Settlement space organization mode: The colony space organization model can be summarized as "a clan group guided by blood relationship,a natural group guided by water system,a road-oriented traffic group,guided by public service facilities.There are five types of public service group and farming group guided by production methods.Quantitative analysis of the spatial structure characteristics of traditional rural settlements in the Chengdu Plain can provide a scientific basis for the spatial composition of traditional rural settlements in the Chengdu Plain.Through the quantitative analysis,the general law and quantifiable reference index are summarized,which provides reference for the protection and renewal of the settlement space structure at different scales.