Spatial mechanism and optimal allocation of rural settlements on village scale based on Voronoi diagram—Taking Dazhu Village in Hechuan District of Chongqing as an example

The scattered spatial distribution，weak gathered function and inefficient use of rural settlements， are poor phenomena of rural area system evolution in the process of Rural-Urban transformation，analyzing the spatial mechanism and making appropriate spatial optimization strategies have become the breakthrough of land resources rational use，promotion of construction of new countryside and integration of urban and rural development. We chose the Dazhu Village in Hechuan District of Chongqing as the sample，and adopt the method of Voronoi diagram combined with GIS to analyze the spatial distribution characteristics of rural settlements and the spatialed distribution index under the influence of different space factors. The results showed that whole rural settlements distribution of Dazhu Village was the cluster type with 3 distribution modes：spot，ribbon pattern，bulk，but there was a random difference among communities. The distribution exponential trend line of rural settlements showed some regularity，the rural settlements prefer red to 1 to 3 terrain niche，0-200 m water source buffer，0-100 m trunk roads buffer. According to the mechanism of rural settlements spatial distribution，combined village domain differentiated environmental conditions and the demands of farmers，we constructed three kinds of spatial optimization modes，which were the public service facilities leading type，advantaged rural settlements leading type，traffic trunk leading type，and also established“ local-centers” rural settlement system， which regarded the central village as the core，grass-roots village as assistance.