Control Points for Quality of Arable Land Quality Monitoring in Daxing District, Beijing
北京市大兴区耕地质量等级监测控制点布设

Variogram modeling for monitoring the sample point layout of monitoring points provides a way for controling monitoring costs and improving monitoring accuracy. Using Daxing district in Beijing as our focal area we investigated the quality of cultivated land level monitoring and control point layout methods. We adopted a combination of theoretical modeling and empirical analysis. The total cultivated area of Daxing district is 62.44 ha. Through the analysis of natural and other index variation function, the variation of the radius of cultivated land level monitoring in Daxing is 3.72 km. Emplaced theory of monitoring point is 43 and the control range for each monitoring point is 10.86 sqare km. Considering soil types (subclasses), land use planning, the area ratio of each land natural level, the area ratio of each land-use level, land consolidation projects, and sample distribution uniformity, the number of reasonable layouts of the monitoring points was 46 to meet the quality and grade of the area of farmland monitoring precision. The variogram theoretical model of application value in the research quality of arable land level monitoring points in the layout process can improve the representativeness of monitoring points and the integrity of arable land quality monitoring information. Insufficient consideration to the agricultural conditions of the study area facilities: agricultural facilities change the value of α in the agricultural land classification, and can significantly improve the use levels of agricultural land, thereby affecting the entire study area of cultivated land use types. Further research is needed in this area. Daxing district is a plain area where the geological conditions are relatively homogeneous and the quality of cultivated land is also relatively concentrated. Therefore, the research methods presented in this paper should be further tested in regions containing complex geological conditions.