| The amount of cultivated land and its quality problems are related to our country’s food security and social long period of stability and security. The basic situation of our country also determines the cultivated land protection should pay equal attention to management of the implementation of quality and quantity, and the scientific and reasonable layout of cultivated land monitoring point, which has the very vital significance to implement the arable land protection policy. This paper is based on the classified results of agricultural land in Wuxue City, and introduces the theoretical model of variation function. This paper discusses the variety of influencing factors and regulations of the cultivated land in research area of 1:10000 spatial scales. Calculating the radius variation function of sample points accurately and using the ordinary Kriging interpolation method to correct the present situation of the study area appropriately, realizes the sampling points to "fan out from point to area"; more accurately reflect the situation of quality grade of cultivated land in Wuxue city. The research results show that the sample in the layout of monitoring points in this paper can meet the requirements of the quality of cultivated land grade monitoring. Conclusions are as follows:1.According to the principle and method of monitoring and controlling area, divide it into "natural quality partition", "land use level partition", "horizontal partitioning land benefit", and the soil layer of three partitions in ArcGis are overlay processed, draws 15 areas of farmland quality monitoring control.2.Researching the regularity of variation under the space size of 1:10,000, using the method of variety function and fitting model, fitting direction of the study on the spatial correlation and its variations of regional cultivated land quality. The research shows that the spatial heterogeneity of the direction of cultivated land in Wuxue quality monitoring sampling points is the main north-south direction.Applied to statistical analysis module of ArcGis cross validation of each model in the study area, the results show that when using Gauss model to simulate the variety function is proposed to fit, which has the minimum error and can reflect the spatial changes of the cultivated land quality best, therefore to simulate variation by using the gaussian model.3.Through the analysis of the variation function model of the study area, and combining with the sample correction factors, this determines to set up the founded layout monitoring sample 97, including 81 fixed monitoring samples and 16 dynamic monitoring samples.4.Through the analysis of cover of the layout monitoring points in the research area, this shows that the monitoring sampling points in each study area almost covered all ranks of natural, use and economy and so on in Wuxue city. Besides, the proportion of all grades that are covered by monitoring the sample is very close to the proportion of arable land, which shows that it is very typical and representative of the layout of sampling points in this paper. The verification results show that the interpolation accuracy is high when we use ordinary Kriging method on the layout of monitoring points. |
