Protection zoning of arable land quality index based on local spatial autocorrelation

Abstract: Protecting arable land is to protect the foundation of development and ensure the food safety in China. To formulate a scientific and reasonable protection scheme is an important guarantee for arable land under the tendency of hierarchical and fine management. Taking Guangning county of Guangdong Province as an example, the paper conducted a study on the protection zoning of arable land. The actual study process and content were based on the quality evaluation of arable land, and combined the Moran scatter plot and local spatial autocorrelation analysis together to explore the spatial structural characteristics and agglomerate regulation of arable land quality by taking the arable land quality index as the spatial variable and taking the administrative village as the spatial unit. On the basis of it, we put forward the protection zoning of arable land. The main results of the study were as follows: Firstly, the arable land quality exhibited an agglomerate regulation to some extent in spatial distribution in Guangning county. From the point view of natural quality of arable land, the eastern of county was higher than the western, while the high quality arable land which mostly gathered at the central and western of county was higher than the northern and eastern of county from the point view of use quality and economic quality of arable land. Besides that, the positive spatial autocorrelation of arable land quality which contained the High-High type and the Low-Low type emerged as the shape of cluster and had a powerful agglomeration, while the negative spatial autocorrelation which included the High-Low type and Low-High type barely had a concentrate region, and most of them distributed dispersedly with barely outstanding regular pattern. Secondly, different kinds of protection zoning scheme were put forwarded based on the local spatial autocorrelation analysis of arable land quality indexes. According to the spatial agglomerate characteristics of natural quality of arable land, the protection zone of arable land was divided into four sub-regions which included the restrict construction region, the comprehensive improved region, the moderate improved region and the key improved region. Each sub-region of arable land natural quality had its distinctive agglomerate attribute and distribution property, therefore kinds of protection measures and advices were proposed in a line with it, for example, the High-High type of arable land natural quality located at the north of Paisha town, the central of Jiangtun town and the south of Luogang town in a great measure, the best way to protect it was to sustain the existing natural level and forbid non-farming construction. Besides, from the perspective of utilization level and output effect of arable land, kinds of using region and productivity region were also proposed too. Thirdly, the protection zoning were put forwarded through the local spatial autocorrelation analysis of arable land quality indexes in accordance with different connotations of arable land which contain the natural quality, use quality and economic quality, the corresponding spatial agglomerate types of arable land include the High-High type, Low-Low type, High-Low type and Low-High type. Traditional zoning pattern of arable land was most likely to take the natural endowments, utilization level and economic affordability into account, while in the paper, the protection zoning scheme of arable land not only think about those factors, but also take the spatial agglomerate characteristics of that into account, and treat the spatial factor of arable land as the 'fourth dimension' which break though the traditional zoning pattern. The local spatial autocorrelation analysis expanded the regionalization basis of arable land protection and can provide a new thought for the hierarchical and fine management of arable land. At last, kinds of protection measures were put forwarded according to the sub-region schemes which based on the local spatial autocorrelation analysis of arable land quality index, those will provide a reference for arable land protection in Guangning county.