Research On The Change Of Cultivated Land Quality Level And Agricultural Space Protection Based On The Scale

As a famous land of fish and rice in China,Dongting Lake Plain is an important commodity grain and oil base in China,with a solid foundation of agricultural production.Locating by the Dongting Lake,Yueyanglou District has fertile land and rich resources,and is a typical representative of Dongting Lake Plain.This study,based on the AHP entropy method,comprehensive index model,gravity center model,spatial Gini coefficient method,spatial autocorrelation analysis method to analyze the changes of cultivated land quality level and conservation zoning of agricultural space,and taking Yueyanglou District as an example and taking the cultivated land in the land change survey database as the evaluation unit,hopes to provide some basis and reference for cultivated land protection.The main conclusions can be drawn as follows:(1)Through calculation and analysis of the cultivated land concentration index in Yueyanglou District,it is concluded that the spatial distribution of cultivated land in Yueyanglou District is relatively concentrated and has a trend of further enhancement.(2)In this study,the cultivated land quality evaluation index system was constructed from four aspects of natural quality of cultivated land,reginal conditions,utilization conditions and the stability of cultivated land,and the cultivated land quality of Yueyanglou District in 2010 and 2018 was evaluated.The results showed that the trend of cultivated land quality of Yueyanglou District from 2010 to 2018 is upward,mainly in first grade land and third grade land,and the spatial distribution of cultivated land quality grades in the two periods was similar.(3)From 2010 to 2018,the offset of the first grade land was the largest,and the offset of the third grade land was the smallest,with the offset distance of 714.53 m and94.47 m respectively.In terms of the spatial change of the center of gravity of cultivated land quality grade at Township scale,the offset from smallest to largest order was 393.10 m for the fifth grade land of Sanhe Township,454.14 m for the fourth grade land of Tonghai Road office,867.35 m for the third grade land of Tonghai Road office,and the second grade land of Xitang town 49 m and 1460.36 m respectively.In addition,by calculating the Gini coefficient of cultivated land space,it is concluded that all levels of land tend to be evenly distributed in Yueyanglou District.(4)There is local spatial autocorrelation in cultivated land quality,in which HH and HL types are consistent with the distribution of high-quality cultivated land,LL and LH types are consistent with the distribution of low-quality cultivated land.Combined with the results of comprehensive evaluation of cultivated land quality and local spatial autocorrelation analysis,three protection zoning schemes are divided,including core protection area,priority improvement area and comprehensive improvement area,to meet the practical needs of cultivated land protection and management according to local conditions.