Study On Site Selection And Construction Of High-standard Prime Farmland Based On The Trinity Of “Quantity-quality-ecology” In Yangtze River Delta Economic Zone

High-standard prime farmland construction is the main goal and core task of land consolidation at present,which is of great significance to realize the trinity of “Quantity-quality-ecology” protection of cultivated land.There are some problems: the existing standards are lack of regional differentiation guidance,ecological and landscape elements of the selection of evaluation indicators are less considerated,and there are few research on consolidation patterns and ecological strategies.On the basis of drawbacks,requirements and approaches of trinity construction about “quantity,quality and ecology” of high-standard basic farmland construction at present,using spatial analysis of ArcGIS,field investigation,redundancy analysis,TOPSIS,and factor combination method,according to characteristics of cultivated land resource and present situation of high-standard prime farmland construction in Yangtze River Delta Zone,this thesis focuses on the method of target area selection,consolidation region division,ecological strategy design and post construction management,takes Jiangdu distrit in Jiangsu province as a case and provides theoretical and practical basis for promoting trinity construction of high-standard basic farmland in Yangtze River Delta Zone.The main research conclusions are drawn as follows:(1)China's land consolidation has developed into ecological comprehensive consolidation stage.Ecological civilization construction has put forward the new requirements: “quantity control,quality management,ecological protection” for high-standard prime farmland construction.But there are some problems in “selection,construction and management” of high-standard basic farmland in China: construction standards are not uniform,lack of regional differentiation guidance and ecological landscape consideration,which limits the realization of "high standards".(2)The main driving factors of land consolidation are social,economic and policy factors in Yangtze River Delta Zone.There are 9 significant factors(P(27)0.05).Especially,fiscal transfer payment has great influence,the correlation coefficient of the first axis is up to 0.861.However,natural and ecological factors are less consideration land consolidation site selection.Based on case study,high-standards basic farmland construction success depends on natural condition,clear planning,sufficient funds and so on.But there are also some limitations,such as lack of scientific evaluation,ecological design and post management.(3)It takes controlling construction indicator and selecting target area to protect high-standard prime farmland's quantity.Construction target selection should strengthen the natural,ecological and landscape index,focus on quality and ecological protection.According to the evaluation result,the number of target area of high-standard basic farmland construction in Jiangdu District is 2878,and the scale of construction is 63575.71 ha.On the basis of relative closeness sorting,the scale of priority construction area(Ci?0.74)is 16862.58 ha,the scale of suitable construction area(0.45(27)Ci?0.74)is 16313.12 ha,the scale of reserve construction area(0.16(27)Ci?0.45)is 20953.08 ha,the scale of unfavorable construction area(Ci(27)0.16)is 9446.96 ha.Combined with high-standard basic farmland construction tasks in 2020,there are 59433.33 ha construction target area being selected.(4)It takes zoning construction on basis of restrictive factor and ecological consolidation to protect quality and ecology of high-standard prime farmland.Based on the analysis of limiting factor combination and consolidation project's difficulty,the area that needed to be constructed is divided into 6 types,named the area of comprehensive construction,the area of increase soil fertility,the area of sloping field remediation,the area of improving irrigation and drainage condition,the area of field road construction,the area of improve water quality.The construction scale of each consolidation area is 17139.26ha?6274.68ha?4858.33ha?18973.69ha?7914.13ha?8415.60 ha,respectively.The largest areas of the region are the area of improving irrigation and drainage condition and the area of comprehensive construction,the regional proportions are 29.84% and 26.96%.It takes ecological strategy to construct high-standard prime farmland,like using organic fertilizer to increase soil fertility,constructing ecological ditch and field road,improving farmland water quality,low carbon management.High-standard prime farmland construction should attach importance to the post management based on the trinity of “Quantity-quality-ecology”.