Potential Calculation And Zoning Of County-Level Agricultural Land Remediation From The Perspective Of Heavy Metal Pollution

County-level land consolidation planning is the basic basis of land consolidation activities.Facing the severe situation of heavy metal pollution in agricultural land,agricultural land consolidation is an important measure to improve the quality of agricultural land.Pollution prevention and control is the focus of agricultural land consolidation planning.Potential estimation and zoning are important components of land consolidation planning,which guide the implementation of planning arrangements.Therefore,this paper takes Yixing City,Jiangsu Province as the research area,and on the basis of ‘Yixing Land Regulation Planning(2011-2015)' and referring to the current ‘Rules for Preparing County-level Land Regulation Planning',explores the method for estimating and zoning the potential of County-Level Agricultural Land Regulation from the perspective of heavy metal pollution.In terms of quality potential,two kinds of amendment methods were used to obtain the quality potential level of agricultural land remediation by using the pollution grade of heavy metals and the utilization grade of heavy metals,respectively.On this basis,the planning zoning of agricultural land remediation was carried out.Finally,focusing on the remediation of heavy metal pollution,this paper puts forward some suggestions on the revision and improvement of the current ‘Rules for the Compilation of Land Regulation Planning at County Level'.The results show that:(1)Four townships in the first-level district with quantitative potential were identified,reaching 1 506.21 hectares;11 townships in the second-level district with an area of 1920.83 hectares;and seven townships in the third-level district with 157.91 hectares.In the first scheme of quality potential estimation,the utilization grade is 5-10,the utilization level of grade I area is not less than 1.38,the utilization level of grade II area is less than 1.38 but not less than 1.10,and the utilization level of grade III area is less than 1.10.In the second scheme,the utilization level is 5-9,the utilization level of grade I area is not less than 1.21,the utilization level of grade II area is less than 1.21 but not less than 1.01,and the utilization level of grade III area is less than 1.01.Comparing the calculation results of three times of quality potential before and after,it shows that the increase of heavy metal pollution indicators is more in line with the actual demand.(2)Taking Yixing City Land Reclamation Planning(2011-2015)as a reference,the objectives of the planning are determined,and 577.6 hectares of arable land can be supplemented in 2016-2020.The quality of agricultural land can be upgraded by one level,and the heavy metal contaminated areas can be rectified to the level of safe utilization.According to the potential results of quantity and quality of agricultural land remediation and the pollution degree of heavy metals,the study area was planned and arranged.Five different levels of remediation planning were divided.There were differences in timing arrangement and key points of remediation among different levels.(3)Based on the results of the study and the deficiencies in heavy metal pollution in the current ‘Rules for the Compilation of Land Regulation Planning at County Level',the contents of investigation and evaluation,methods,classification summary and planning arrangement related to agricultural land regulation planning in the Rules should be supplemented and improved,which will further improve and standardize the methods of land regulation planning at County level.Provide reference.