Spatial Differentiation Of Rural Settlements And Optimization Of Ecological Security Pattern In The Hilly Areas Of Eastern Sichuan

The hilly area of eastern Sichuan has a complicated geographical environment,and its rural settlements have obvious spatial differentiation characteristics,and at the same time,they also have hidden danger of ecological security of different degrees.Therefore,to analyze and explore the spatial pattern of rural settlements in the eastern Sichuan hilly region and its hidden ecological security risks can provide theoretical basis and reference for the reconstruction of beautiful and appropriate rural residential landscape and national spatial planning.As a result,based on the large agricultural county in hilly region of Sichuan province-Nanbu county(presides over 71 villages and towns,2)neighborhood office of rural settlements as the object,using the method of average nearest neighbor index,Voronoi,the density of nuclear analysis,the global spatial clustering calibration methods of "hot spots" and space analysis,explore the Nanbu county rural settlements spatial pattern characteristics,and from two aspects of natural and social cultural factors analysis of settlement influence factors of spatial pattern,reveal the relationship between them.On this basis,the ecological security pattern of Nanbu county was established,the rural settlements in Nanbu county were classified and corresponding optimization measures and Suggestions were put forward.The main conclusions are as follows:(1)From the perspective of rural settlement spatial distribution,the rural settlement space in Nanbu County presents an agglomeration distribution pattern on the whole,with the characteristics of coexistence of dispersion and aggregation in some parts.The rural settlement aggregation degree is high in the central and northwestern areas,and relatively low in the eastern and western marginal areas.The density of rural settlements tends to increase from the geometric edge of county to the center.(2)In terms of the spatial scale of rural settlements,the scale of rural settlements in Nanbu county is greatly different,and the classification is obvious.The proportion of single courtyard settlement and small settlement is relatively high,while that of medium and large scale agglomeration distribution is relatively small.On the whole,the scale of settlement shows the characteristics of low-value agglomeration.There are significant differences in the local scale distribution,with obvious high-value clustering region and low-value clustering region.The area of "hot spot" is higher than that of "cold spot",showing the spatial differentiation characteristics of "large in the middle,small in the east,west and south,and moderate in the northwest".(3)From the analysis of the spatial pattern of settlements,the rural settlements in Nanbu County are characterized by the coexistence of banding type,mass type and dispersed type,and the degree of intensive evacuation of settlements is affected by the banded features such as rivers and traffic,as well as the contiguous patches of cultivated land and forests.(4)The spatial pattern of rural settlements in Nanbu County is mainly influenced by natural and social and cultural factors.Among them,elevation,slope,traffic and hydrologic factors have significant influence on the settlement distribution in Nanbu County,with the largest number and area of settlements within the range of 350-450 m and 0-10° of slope,and more than 60% of the settlements are distributed within the range of 400 m from the river.With the increase of elevation,slope and distance from river or road,the number and area of settlements decrease step by step.There was no significant correlation between organizational town factor and settlement spatial pattern in Nanbu county.In terms of social and economic factors,the main indexes that affect the pattern of settlement distribution include per capita net income of farmers,population density,total area of cultivated land and total power of agricultural machinery.The main indicators that affect the scale pattern of settlements are the number of regional labor force,the per capita floor area of rural residents,agricultural income,per capita net income,etc..(5)Build Nanbu county ecological security pattern and on this basis could be divided into priority development-oriented Nanbu county rural settlements,moderate constructive,restrict expansive and focus on the type of the four optimization types and to put forward the corresponding optimization countermeasures: developmental priority groups should develop large-scale population of villages,improve local traffic condition,strengthen the relationship between settlement and promoting economic development;Moderate construction settlements can be appropriately expanded and cultivated for agriculture or ecological cultivation to promote the development of local economy,but the ecological damage should be avoided.At the same time,we should make great efforts to control the environmental pollution in rural areas,improve the infrastructure construction,and improve the livability and happiness of the villagers.In order to improve the living environment in rural areas,the residents should be transferred to the priority development settlements.In order to protect the ecology,measures such as returning farmland to forest and grassland should also be taken in areas with serious ecological damage.