Arable Land Quality Evaluation In Yixing Based On Grey Target Model

Arable land resources are the best part of land resources,which are the basic conditions for people to get agricultural products.It plays a vital role to ensure national food security and social stability.With the acceleration of the current process of urbanization and the rapid expansion of population,Construction Land is expanding,and China is also faced with land degradation,severe loss of quality arable land,lack of untouched arable land resources etc.The contradiction between population growth,economic development and arable land protection is increasingly sharp.In this context,it's very important to understand the current situation of arable land and study the temporal and spatial variation of the number and landscape pattern of arable land.It is of great theoretical and practical significance to introduce the gray target model for the evaluation of arable land quality,and to put forward the corresponding protection and management measures for different quality grades of arable land.This paper take Yixing City,Jiangsu province as research area,and we studied the following aspects based on three-period data.1.Study on temporal and spatial change of arable landThis article studied temporal and spatial variation of the total arable land,the conversion of arable land and landscape pattern changes.Through analysis,we understand the current grim situation of arable land protection,then make sure the purpose and task of the quality evaluation of arable land.2.Quality evaluation method of arable landThis part analyse factors affecting the quality of arable land,and the principle of index selection.Then the evaluation model of arable land quality is constructed by introducting grey target model,taking the natural endowments,soil conditions and use conditions,land spatial shape index into account.3.Results and CountermeasuresIn order to better protection of arable land,evaluatiing the quality of arable land on the basis of temporal and spatial changes analysis of arable land.In view of the different quality grades of arable land,the measures for protection and management are put forward..Through research,the main conclusions of this paper are as follows:(1)In this paper,the dynamic changes of arable land,landscape index reveal the dynamic changes in the number,spatial distribution characteristics of arable land,the change of arable land landscape and so on.Analysis found that the increase in Yixing city's arable land area is 4898.56hm2,and dynamic change is 3.32%from 2006 to 2009.The arable land area decreased 499.88hm2,and dynamic change of arable land is-0.31%.Degree of fragmentation of arable showed an overall increasing trend.Present situation of arable land protection situation is grim.Conversion of cultivated land and construction land and water area is intense and the quantity of arable land decreased.Arable land spatial fragmentation problems highlighted.Therefore,it is necessary to protect high-quality and contiguous land to realize the sustainable utilization of arable land.(2)Based on comprehensive evaluation index selection,the quality of arable land was evaluated by using grey target model.The evaluation results showed that the grey target model can effectively solve the problems such as subjectivity,uncertainty in quantification of index and so on,which makes the evaluation result more reasonable and credible.The arable land of Yixing is overall good.Highest quality?higher quality and medium quality land degree make up 84 percent of the total arable land.From the spatial distribution,quality of arable land of the northern region is better than that of the south.There are significant differences in the quality of arable land between towns,and arable land of high quality mainly distribute in the Xu She town,Yang Xiang town,Fang Qiao town etc.This article also put forward suggestions of protection and utilization for different grades of arable land.