Spatial Evolution Of Settlement In Plain Agricultural Areas

In the context of rapid urbanization,analyzing the existing distribution of rural settlement and exploring the evolution and optimization of rural settlements for new era and sustainable development is one of the breakthroughs to solve rural problems.Rural settlement is the development vector of broad plains of agriculture area in Henan province.Study on development of rural settlements in plain agricultural areas in Henan province is significant to promoting urbanization in Henan province and enhancing the level of beautiful village construction of Henan.Selecting Yanjin County located in Northern Henan province as an example,the paper discusses the change of settlement from layout condition,scale,changes in spatial form,space structure,influence factors and development stage from using statistical analysis,GIS spatial analysis,landscape analysis and other methods.1.Settlement in the study area is small but quite different.The average population size is 1278,but the maximum(5532)is 32 times the size of the minimum(175).The land size distribution of settlement is similar to population size distribution.The small settlement is more,the mean patch area is 32.48 hectares,20%of the settlement is less than 10 hectares,the number of the settlement more than 100 hectares is only seven.The distribution of the settlement is closer to the road,but the current distribution and the extended area within the study period have no obvious correlation to the distance from the township.2.The scale of settlement expands significantly.The scale of total settlement expands nearly 3 times from 1972 to 2013.From the county level,the increased area in the period of 1972-1990 is over the 1990-2013,but the difference of expansion intensity of these two periods is small.At the level of township,the growth of settlement is in line with distance attenuation-farther away from the county seat,extended degree weakens.The settlement area of village near the roads,towns and industrial area increase more,the whole settlement area of village continues to increase and the changes is complex.Zipf index and fractal dimension can measure the changes of the size distribution of the settlement.Zipf index shows that the lower rank settlement grows rapidly in 1972-1990,the high order settlement grows rapidly in 1990-2013.The rank-size curve elapses outward over time,settlement patch size distribution in the study area is concentrated,the advantage of high order size settlement declines.Fractal dimension shows that patch size tends tobe balance and settlement of the middle order is more.The hierarchical structure of settlementmanifests thathighest grade appears,medium grade increases,lowest grade continues declining.The low grade upgrades to a high level.But because of the absolute superiority of county seat,the highest gradehas no increase in the number.In General,settlement scale in the early 70's is small and then scale grade is gradually medium settlement-oriented.The hierarchical structure of settlement needs to be further optimized.3.Landscape index shows that the number of settlements patch reduces in the study period,maximum patch size expands significantly,the distance between patches is getting bigger,average shape index becomes larger but overall settlement patch shape is regular.Patches of most settlement are expanding.According to the direction of settlement growth,four types which are four-week extension,integrated extension,along the road extension,new addition are divided.The expansion type of study area is mainly four-week extension.4.Taking the seat of government as administrative center of township,we analyze the fractal characteristics of spatial structure of townships and then compared with the geometric center and distribution of settlement center,it shows that the force between the townships is small and the distribution of townships is scattered and relatively uniform.Distribution of settlement centre coincides with the geometric centre and far from-the administrative centre.It shows that the township doees not have very good radiation for the development of settlement.5.Population growth and family scale miniaturization makeresidential demand increase;economic development make villagers can improve their living conditions;the improvement of traffic conditions causes settlement layout to concentrate near road but to a certain extent it will hinder the further growth of settlement;Government policy makes settlement evolutiondeviate from original law,such as the concentration of living or the new added land use of settlement;the missing of the planning management lead land waste phenomenon to appear.These factors have major impacts on the evolution of rural settlements and also promote settlement distribution and space layout to adapt to requirements of economic and social development.6.According to settlement scale and the changes in spatial form,this paper divides evolvement of settlement into three stages.The settlement in plain agricultural areas has experienced even distribution,different development and evolves from the uniform distribution adapting to the original homogeneous conditions to the more balanced and rational mode that the scale of settlement patch is larger,the number is fewer and the distance between patches is farther.Plain agricultural areas are frontier regions of the future urbanization development and also potential areas of intensive land use.