Study On Planning Of Permanent Basic Farmland In Mile City-based On Arable Land Comprehensive Quality

"Treasuring,rationally using land and protecting farmland in earnest"is one of China’s basic national policies.In recent years,with the continuous development of social and economic level,and the continuous expansion of the population size,China’s arable land protection is currently facing the problem that-protection quantity met requirement,but its quality and sustainability are declining year-by-year.In the scope of major cities,the high quality arable land around towns is frequently occupied or contaminated by construction land.In order to effectively protect high-quality,high-yield arable land,in 2014,China first emphasized the concept of permanent basic farmland,and implemented in national scope,defined the protection main body and responsibility in 2016-2017.However,although the demarcation process of permanent basic farmland is relatively complete,Yunnan Province,as one of the typical mountainous provinces in the southwestern border region of China,has the urgency of relieving the current situation of farmland being frequently occupied and its quality declining,also it has the special nature of the need to fully coordinate with the local socio-economic development,the above characteristics determine that the specificity and complexity of the local permanent basic farmland planning.Therefore,based on the difficulties faced by the land use and arable land protection in study area,innovative planning methods of permanent basic farmland has important theoretical and practical significance for the permanent basic farmland planning in Yunnan Province and similar regions.This paper uses the Mile City in Yunnan Province as the research area and the whole arable land as the research object.Firstly,based on the historical yearbook data and land change survey data,the arable land and grain production changes in the past years in Mile City were analyzed,we expounded the necessity and systematism of the permanent basic farmland planning.Based on the results of the analysis,this paper first constructed arable land comprehensive quality index system which including the natural quality of arable land,ecological quality,productivity,and location conditions.The single-factor assessment of arable land in Mile City was performed.Then TOPSIS prioritization method was used.The city’s arable land are divided into five levels according to their priority levels,and also results will linked to other plans such as the adjustment of land use master plans,forest land conservation plans,and water source protection plans,eliminating the arable land which has poor quality or high conversion possibility.Then from the aspects of the satisfaction degree of permanent basic farmland indicators,quantity distribution,comprehensive quality comparison and spatial distribution,the differences between the planning results of this paper and land department planning results of the permanent basic farmland in 2017 were contrasted and analyzed.The results of this study are as follows:(1)By constructing the Mile City arable land comprehensive quality permanent basic farmland planning system,we replenish the permanent basic farmland planning index system in mountainous areas,and innovates the planning method of permanent basic farmland.Based on the fact that study area has widely spread mountainous areas and sparsely flatland,the effective soil thickness,irrigation guarantee rate,soil organic matter content,topsoil textureterrain slope,Connectivity,degree of rocky desertification,the distance between arable land and main road,township,and residential area are selected.There are total 10 indicators are selected,by evaluating2014 Mile City’s arable land single factors;we can using TOPSIS method and planning convergence method,finally planning Mile City’s permanent basic farmland,its total area are 69836.69hm~2.Planning results has excellent natural and ecological quality,and good location conditions.(2)In order to verify the scientific of permanent basic farmland planning system based on arable land comprehensive quality,the comparative study of the planning results of this study and the national land department is conducted from the aspects of index satisfaction,quantity distribution,comprehensive quality,and spatial distribution..The results of the analysis show that both side’s permanent basic farmland planning results is consistent in terms of the degree of satisfaction,spatial distribution and location conditions,and the results of national land department guarantees higher satisfaction of the flatland area and surrounding urban areas;but this paper’s planning results has excellent natural,ecological quality and high productivity levels.Although both sides’planning results can ensure the effective protection of permanent basic farmland quantity and quality in the near future,due to the scientific and reasonable index system,the planning results based on arable comprehensive quality are more in line with the actual conditions and fits future development needs in study area.