Study On Change Of Cultivated Land Quality And Landscape Pattern Index And Its Correlation In Ji'an County

Cultivated land is an important part of land resources,which is a solid foundation and guarantee for humans` survival and development for a long time.In modern countries,cultivated land is not only the material basis for satisfying the basic food needs of the people,but also the quantity and quality of agricultural production in a country,and the solid guarantee for ensuring national food security.With the further advancement of industrialization and urbanization,the number of dominant cultivated land resources caused by construction occupation,disasters,ecological depriving of cultivated land,and agricultural structure adjustment has been seriously reduced.The protection pressure on basic cultivated land is multiplying,and the balance of cultivated land compensation has been “preempted”.The phenomenon of "better cultivated land occupied and worse cultivated land supplemented " is prominent.Under the red line of arable land protection,the trend of " Pay attention to quantity,ignore quality" appears,making the average quality of cultivated land in the country drop seriously.In order to improve the quality of cultivated land in China and improve the comprehensive production capacity of cultivated land,this study compared the results of cultivated land quality assessment in 2015 with the results of cultivated land quality assessment in 2011 on the basis of the evaluation of cultivated land quality,and explores the change trend of Jian County arable land quality in the 5 years of 2011 to 2015.At the same time,by using the landscape pattern index analysis method,some landscape pattern indices were selected to analyze the corresponding changes in the pattern of cultivated land landscape patterns,and the correlation between cultivated land quality and landscape pattern index in the study area was studied and discussed.The results show that the study can understand the difference in cultivated land quality under different natural conditions and different levels of human activities and the difference in cultivated land quality under different landscape patterns,and explore the landscape structure optimization measures to improve the quality of cultivated land to provide the landscape ecological basis.The main conclusions of this study are as follows:(1)Compared with 2011,the cultivated area of Ji'an County in 2015 was increased by 129.75 hm2,the largest change range of the weighted average quality grade of cultivated land was the national economic level,the second was national use level,and the smallest change was national natural level.Among them,the cultivated land area weighted average national natural level and use level increased 0.04 level,the cultivated land area weighted average national economic level increased 0.06 level.The coefficient of variation of the national natural level,national use level and the national economic level respectively increased 0.08%,0.15%,and 0.01%,compared with 2011,the difference in the quality of cultivated land between farmland individuals gradually increased.(2)With the change of the quantity and quality of cultivated land,the structure and spatial distribution of cultivated land changes with the change of the external characteristics and intrinsic attributes of cultivated land.Compared with 2011,whether it is national nature level,national use level,or national economic level,the descriptive indicators of each landscape pattern index showed a decreasing trend as a whole in 2015.Reflecting the regularity of plots of cultivated land of various quality and other aspects,the fragmentation of cultivated land has improved,although the average area of plots of cultivated land has decreased,the number of large-area cultivated land has increased.Relatively speaking,from the perspective of reduction,due to the small spatial and temporal changes in the natural conditions of cultivated land,part of the conditions for the use of cultivated land and the economic benefits of utilization can be enhanced by human-made transformations,made the decrease in the descriptive index of the cultivated land landscape pattern index of national use level and national economic level is greater than that of the national nature level,which means that the quality of cultivated land and the quality of the economy have been improved overall.(3)The results of correlation analysis between the cultivated land quality index and cultivated land landscape pattern Index show that: Cultivated land area weighted average national natural index was negatively correlated with the division index of cultivated land,which was positively correlated with the contagion index,and negatively correlated with Shannon`s Diversity index;Cultivated land area weighted average national use index was negatively correlated with the contagion index;Cultivated land area weighted average national economic index was positively correlated with the contagion index,which was negatively correlated with Shannon Diversity index.The change of cultivated land landscape pattern index reflects the more regularity of cultivated land,the improvement of farmland fragmentation and the increase of large area cultivated land,which can reveal the rising trend of cultivated land quality in the study area.