Analysis Of Basic Farmland Quality Of The Two Overall Land Use Planning And The Discussion On Agricultural Land Classification ——A Case Study Of Daxing County And Tongzhou County,Beijing

Cultivated land is very precious and is the most easily destroyed one of natural resources.The basic farmland is the essence of cultivated land.Protection and designation of basic farmland is a top priority of the protection of cultivated land.For a long time,The layout adjustment of basic farmland In the overall land use planning exist problems such as "focus on quantity,ignoring quality ".Agricultural land classification is an important part of the land survey project in the new round of land resources survey.However,since the end of the agricultural land classification,it has not been updated.Existing agricultural land classification results can’t assess the basic farmland quality accurately by the influence of low precision of land use data and lack of data currency.At the same time,there is no similar studies on planning of basic farmland distribution adjustment based on agricultural land classification update.Therefore,this paper use theoretical analysis,GIS technology and statistical analysis,takes Daxing District and Tongzhou District for example,analyze the quality of the basic farmland layout based on agricultural land classification update.The results of the study show that,the basic farmland in Daxing District in accordance with the last round-before agricultural land classification update in current round-agricultural land classification updates in current round trends,average natural quality gradation index is 2381.71-2374.36-2377.15,average natural quality gradation is 11.91-11.87-11.89,average utilization gradation index is 1676.64-1659.55-1661.53,average utilization gradation is 16.77-16.60-16.62,average economic gradation index is 1086.49-1068.61-1069.91,average economic gradation is 10.86-10.69-10.70;the basic farmland in Tongzhou District average natural quality gradation index is 2369.66-2361.85-2362.02,average natural quality gradation is 11.85-11.81-11.81,average utilization gradation index is 1803.59-1799.60-1799.72,average utilization gradation is 18.04-18.00-18.00,average economic gradation index is 1078.18-1076.45-1076.52,average economic gradation is 10.78-10.76-10.77.The quality of basic farmland in Daxing District and Tongzhou District is lower than the last round,although the quality of basic farmland has improved after t agricultural land classification update,but still poorer than the average quality level of the last round of basic farmland.At the same time,in accordance with the requirements of high standard basic farmland,this paper analyzes the dominant factors which impact basic farmland classification and gradation.On the basis of the original grading factors,add indicators centralized contiguous extent and external transport of cultivated land.Then the paper analyzes the basic farmland grade quality based on the amendments to the agricultural land classification index system.The results show that the farmland in Daxing District and Tongzhou District quality has improved significantly.The average natural quality gradation index of basic farmland in Daxing District is promoted to 2447.67 from 2381.71,average natural quality gradation improved 0.33 degree,average utilization gradation index is promoted to1701.05 from 1676.64,average utilization gradation improved 0.24 degree.The average natural quality gradation index of basic farmland in Tongzhou District is promoted to 2388.73 from 2369.66,average natural quality gradation improved 0.1 degree,average utilization gradation index is promoted to 1815.69 from 1803.59,average utilization gradation improved 0.12 degree.According to this study,it is recommended that:Firstly,as basic farmland area is greater than the cultivated area in some district,it is necessary to carry out the evaluation of the garden,woodland and grassland.Secondly,there aren’t enough index in current agricultural land classification,can’t reflect the precise changes in land,Therefore,the paper recommend the following methods to improve:1.Continue doing agricultural land grading on the basis of agricultural land classification,add indicators such as centralized contiguous extent,road conditions and the size of cultivated land in the agricultural land classification.2.Revise the Agricultural Land Classification index system reference to the factors of agricultural land grading and "High standard basic farmland construction specification",add indicators such as centralized contiguous extent,road conditions of cultivated land and external transport.