Study On Spatial Evolution And Influencing Factors Of Cultivated Land Based On GIS

In the acceleration process of new urbanization, industrialization and agricultural modernization, because of urban encroachment, internal restructuring of agriculture, ecological returning farmland to forest, cultivated land which regards as basic resources for human survival and development inevitably shows downward trend. While based on the consideration of basic national policy of farmland protection and requisition-compensation balance, each region of China is to develop large movement of land regulation while occupying the farmland, in order to ensure dynamic balance of the total cultivated land. In the driving of social economic activities and policies, spatial evolution of cultivated land tends to diversification and complication, while the reaserch on spatial pattern, process and law of spatial evolution of cultivated land has important theoretical and practical significance in promoting the protection and rational utilization of arable land resources.The paper takes Longquanyi district as study area, which spatial variation of cultivated land becomes frequent and typical in the process of balancing urban and rural development and rural land regulation. The paper takes cultivated land as research object and analyses cultivated land spatial pattern and its change, characters of landscape pattern inversion of cultivated land spatial evolution, regional unbalance of Longquanyi district by using GIS spatial analysis and mathematical statistics methods, and analyses the influence of different factors on spatial evolution of cultivated land by introducing space fitting function, that is in order to provide reference for decision in the aspects of spatial optimized layout of cultivated land and policy making on the harmonious development of regional social economy and cultivated land protection.Based on the research target, the main conclusions of this paper as follows:(1) The spatial distribution of cultivated land shows gathering trend in Longquanyi district from 2005 to 2013, that mainly concentrates in the northwestern and northern plain, and the spatial distribution features of cultivated land is dense in northwestern and northern areas, while sparse in central and southern areas, and the dense areas extend from northwest to southwest,the sparse areas occur sporadic expansion around the towns.(2)The proportion of cultivated land area which regard administrative village as space cells shows significant spatial autocorrelation, that means the administrative villages which have high or low proportion of cultivated land area show agglomeration state in space, but the local spatial difference has been enhanced. The high proportion of cultivated land areas which show trend of westward reduction concentrate in Xihe, Huangtu, Hongan towns which located in the northern and northwestern areas of Longquanyi district, while the lows which have passed by two stages called spatial diffusion and shrinkage concentrate in urban built-up area and its fringes that regard Longquan street office as hinterland. From 2005 to 2013, because of urban encroachment on cultivated land and rural land arrangement, the local heterogeneity of administrative village appears “hot spot” and “cold spot” areas that respectively located in Lujiao community of Xihen town and Zhaobi village of Chadian town.(3) From 2005 to 2013, the transferred out cultivated lands of Longquanyi district mainly concentrate in urban built-up area and the fringes of main roads, and its flow direction includes urban construction land, garden plot, highway and railway land, and rural settlement; the transferred into cultivated lands mainly concentrate in original cultivated lands’ distribution edge and its cross districts in northwestern and northern areas, its source includes garden plot, rural settlement, pit-pond and ditch land.(4) In the point of characteristics of landscape pattern changes about spatial evolution of cultivated land, the patch numbers and plaque areas of transferred out cultivated lands and transferred into cultivated lands show a decreasing trend with the increase of slope and distance from rivers, towns, roads, rural settlements. But affected by the difference in areas on different levels of factors, patch numbers, plaque areas, the average patch area, patch density index and mean shape index has different variation characteristics.(5) The regional difference of cultivated lands’ spatial evolution is significant that more than 90 percentages of spatial evolved cultivated lands concentrate within 30 percentages of administrative villages, and the regional difference of transferred out cultivated lands has strengthened, while transferred into cultivated lands has weakened. Compared with the years from 2005 to 2009, the barycenter of transferred out cultivated lands has been moved 3409.86 meters to the northwest,and transferred into cultivated lands has been moved 2462.07 meters to the southwest in the years from 2009 to 2013.(6) Based on the judgement of reachability degree about the influence of different factors on spatial evolution of cultivated land, slope, town and rural settlement have significant effects on the spatial evolution of cultivated land, while the effects of river and road are not obvious. Combining with social and economy development condition and implementation of relevant policies, the main factors of pushing cultivated lands’ spatial evolution of Longquanyi district are urbanization and urban development planning which are under the leading of industry economy, rural settlements arrangement and agricultural structure adjustment that are driven by policies.