The Spatial Distribution Characteristics And Influential Factors Of Rural Settlement In Anning Valley

Rural settlements are the complex of rural nature, society, the economy as well as historical development. To some extent, rural settlement plays a role in macro-control of the regional development, but also affects the size and direction of the regional ecological quality and regional economic development. Anning Valley in Sichuan Province is the second greatest plain and an important agricultural production base. Anning Valley is now at its development stage in the urgent need for planning of spatial distribution and layout of rural settlements. Therefore, in this thesis Huanglianguan Town of Anning Valley is chosen as a representative object of study with the assistance of field measurements and survey data. Taken ARCGIS9.3 as a platform, the fractal theory is applied to analyze space distribution characteristics of rural settlements as well as the influential factors of rural settlements. On this basis, layout of rural settlements is optimized. The main findings and conclusions are as follows:(1)Through spatial distribution analysis of rural settlements in Anning Valley, the results show that: ①the correlation coefficient R2 of "rank-scale" data in rural settlement distribution is 0.984, indicating the presence of fractal characteristics of settlement scale; Settlement scale fractal dimension D is 0.9293, showing the size distribution is dispersed and the monopoly of large settlements is stronger than those small ones; lnP (r) is divided into four intervals. Each interval occupies 1.29%,4.47%,34.97% and 58.97% of the settlements’total number; Considering features of population size, the settlement was divided into five levels which are large settlements (town), medium settlements (central village), small settlements (grassroots village), micro-scale settlements and retail settlements. The overall development of settlements in study area is slow and development in the morphology of the settlement is at a relatively low stage. ② Town-Center Village-Grassroots Village correlation dimension double logarithmic coordinates grassroots and village levels correlation coefficient R2 is 0.978, indicating a higher self-similar system in three settlements of the study area. The correlation dimension D is 0.8305, indicating that the Town-Center Village-Grassroots Village system grass space more closely linked, strong spatial correlation, Town-Center Village-Grassroots Village-the village of grassroots self-organizing system evolution in terms of spatial structure with optimized trends; wide range of scale-free zone, three settlements architecture developed well. ③ settlements with town gathering dimension D is 2.0059, indicating that the settlement distribution is scattered. The town has little-effect on the overall distribution of the settlements in the study area, showing no gathering momentum; the gathering dimension D is 1.8214, the spatial distribution of settlement descending from the village center to the surrounding density with the characteristics of cluster distribution. ④ fractal dimension is between 1-1.22, that of the fractal dimension of large settlements is the largest reaching 1.2170, scattered settlements in the shape of the smallest dimension as 1.0246. Lesser extent irregular shape overall settlement, the higher the rating scale settlement, the more irregular shape.(2)By analyzing the influential factors on the distribution of rural settlements in Anning Valley, the results show that:①settlements in the study area landform elements elevation≤ 1500m. The slope of 5° to 8°. Slope biased western slope. Surface undulation is 3.0 m to 5.0m. Surface roughness is between 1 and 1.05. Profile curvature distribution is at 3 ° to 5 ° of the most orderly and frequency of the highest settlements obvious impact on the overall distribution of the terrain, the higher the rating scale settlement, in which the terrain conditions better. ②Overall distribution of rural settlements in the study area show significant river directivity, the number of settlements decrease with distance from the river. Beyond 500m distribution point is not obvious.. The higher the settlement is, the less obvious the river directivity is.③ Within the range of 1000m of national roads and 300m of rural roads, settlements overall distribution of traffic directional obvious connection the role of national highway on the settlement of a strong rural roads, the higher settlement levels, traffic directionality more obvious; ④ Research scale rural settlements, layout spatial structure are affected by ethnic factors, the small overall size of the Yi villages, mostly located in the region of Mid-surface water is not near water.(3)By building the rural settlements suitability evaluation system, land suitability evaluation structure in the study area is obtained. Less suitable area and unsuitable area accounts for 19.47% and 42.02% respectively in the total study area. The number of settlements in those area accounts for 26.06%and 24.13% respectively, indicating that the land settlement land suitability in the study area is low. Less land is available for settlements, as well as a considerable part of the settlement irrational.(4) According to land suitability evaluation results, combining with the existed problem about the settlements’layout, some development model including urbanization development model, proposed priority development model, internal transformation mode and relocation merger model for Anning Valley are purposed to optimize layout pattern of rural settlements and establish a complete three-level system of Town-Center Village-Grassroots Village.