Research On Evaluation Of Cultivated Land Productivity Of Hefei City Based On GIS

Cultivated land is the material basis for agricultural production,and the quality of cultivated land is related to national food security and affects economic development.To carry out the evaluation of cultivated land in Hefei and to find out the quality of cultivated land can provide reference for the formulation of reasonable farmland management policy in Hefei,and provide information reserve for the construction of precision agricultural system.It is of great practical significance to realize the sustainable development of agriculture and ensure the safety of grain production.This paper takes Hefei city as the research area,using the software of geographic information system(GIS)and the county land resource management information system(CLRMIS),adopts Delphi method to select 14 evaluation indexes,builds evaluation system,and builds judgment matrix with analytic hierarchy process.Calculating the weights of evaluation factors,using fuzzy mathematics to determine the membership function of evaluation factors.Finally,the cultivated land strength grade is divided by the cumulative curve method,and the land strength evaluation of the cultivated land in Hefei is completed.The main achievements are as follows:(1)The total area of cultivated land in Hefei is 558830 hectares,and the cultivated land is divided into five grades.The area of first,second,third and four or five,respectively,accounts for 14.85%,31.47%,35%,10.24% and 8.43% of the total arable land.The first-grade land is mainly distributed in Chaohu city and Lujiang county,mainly in paddy fields.The landform types are mainly plains and plateaus.The main soil nutrient contents are in the medium level,and the barrier-free layer has strong irrigation and drainage capacity.The second-grade land is mainly distributed in Feixi county and Lujiang county.The topography is dominated by plains and razed clams.There are sticky layer barriers in a few areas.The irrigation guarantee rate is medium,the discharge capacity is moderate,and the main soil nutrient content is in the medium level.The third-grade land is mainly distributed in Feidong county and Changfeng county.The topography is mainly in the middle slopes.The arable layer texture is mainly in the loamy soil and the middle loam.The type of the barrier layer is viscous maggots and gravel layers,with moderate irrigation and drainage capacity,and the average soil nutrient content.The content decreased compared with the first and second places.The fourth grade is mainly distributed in Feidong county and Changfeng county.The topography is dominated by mid-slopes and depressions.The arable layers are dominated by loamy soil and middle loam.The type of barrier layer is mainly viscous maggot layer,and a few are gravel layers with irrigation capacity.In general,soil nutrient levels are generally at a relatively low level.The fifth grades are mainly distributed in Feidong county and Changfeng county.The topography is dominated by steep slopes,mid-slopes,and paddy fields.The arable layers are dominated by loamy soil and mid-solar.The types of barrier layers are mainly viscous and stratum,and a few are grit layers.;Irrigation and drainage capacity is low,soil nutrient content is low.(2)The contents of organic matter,available phosphorus and available potassium in cultivated land of Hefei were all at a medium level,with an average content of 20.36g/kg,14.46mg/kg,and 102.19mg/kg,respectively.The average content of organic matter in Chaohu is the highest,the content of organic matter in Lujiang county is the lowest,the average content of effective phosphorus in Feixi county is the highest and the effective phosphorus content in Lujiang county is the lowest;the average content of available potassium in Shushan county of Hefei city is the highest,and the available potassium content in Lujiang county is the lowest.The average content of organic matter in black lime soil is the highest,the average content in the black soil is the lowest,the average content of effective phosphorus in the black soil is the highest,the average content is the lowest in the coarse bone soil;the average content of available potassium in the cultivated soil is the highest in the coarse bone soil and the yellow cinnamon soil,and the average content is the lowest in the yellow brown soil.Combined with GIS,the evaluation of cultivated land productivity in Hefei is more precise and efficient,saving time and effort.This paper makes a descriptive analysis of the different grade of cultivated land in Hefei,and puts forward some suggestions for improving the quality of cultivated land and improving the grade of the land,aiming at different grades.