Research On Quality Evaluation And Spatial Characteristics Of Cultivated Land In Xian’an Area Based On Niche Theory

Cultivated land is the cornerstone of national development,the basis for ensuring food security,and the foundation for the country’s long-term development.In the process of modernization,the phenomenon of desertification,abandonment and fragmentation of cultivated land,soil erosion,loss of ability to retain water and fertilizer,resulting in a decline in the quality of cultivated land.Guaranteeing the quality of cultivated land is a key factor for long-term social security,and it is the material basis for consolidating social and economic development.Exploring the factors affecting the quality of cultivated land and the law of spatial variation will promote the understanding of the quality of cultivated land and improve the quality of cultivated land.Taking Xian’an District as an example,this study uses the cultivated land plots of the third national land survey in Xian’an District as the evaluation unit.Based on the collected data,combined with the Delphi method and the current situation of cultivated land use,a cultivated land quality evaluation index system is constructed.The ecological niche model evaluates the quality of cultivated land,and uses spatial autocorrelation analysis,hotspot analysis and geographically weighted regression analysis to analyze the spatial structure characteristics of cultivated land quality.The results are as follows:(1)Based on the focus of cultivated land resource protection,systematically sort out the current cultivated land quality evaluation index system,analyze the existing problems,and focus on the characteristics of cultivated land with complex terrain,and build a cultivated land quality evaluation system with coordinated optimization of natural quality,social economy and spatial form.The significance and difference of comprehensive indicators are further refined according to the reliability and operability of indicator data sources.Finally,according to the social and economic situation and ecological environment of Xian’an District,the final evaluation index system of cultivated land quality is determined.(2)Based on the evaluation index system of cultivated land quality,the evaluation of cultivated land quality in Xian’an District was carried out with the help of ecological niche model and GIS spatial analysis method.Using the natural fracture method of GIS,the comprehensive index of cultivated land quality evaluation in Xian’an district is divided into four grades:high ecological niche,high ecological niche,medium ecological niche and low ecological niche.The results show that,on the whole,high niches are distributed in Wenquan Office,Gaoqiao Town,Shuangxiqiao Town and Henggouqiao Town;higher niches are distributed in Fushan Office,Guanbuqiao Town and Henggouqiao Town.,Tingsiqiao Town and Shuangxiqiao Town;moderate ecological niches are distributed in Guanbuqiao Town,Heshengqiao Town,Yongan Office and Xiangyanghu Town;low ecological niches are distributed in Guihua Town and Damu Township.From the criterion level,the cultivated land plots with higher natural quality niche level are distributed in the northeast to southwest and northwest,mainly in Henggouqiao Town,Shuangxiqiao Town,Gaoqiao Town,Maqiao Town and Guanxi Town.In the intersection of Buqiao Town and Xiangyang Lake,the comprehensive index of cultivated land is relatively low;the higher socioeconomic niche level is distributed in the central urban area and gradually spreads out;the higher landscape ecological niche level is distributed in the northeast and Southeast.(3)According to the spatial analysis method,spatial fitting analysis was carried out on the evaluation results of cultivated land quality.Using spatial autocorrelation analysis,it can be seen that the quality of cultivated land not only has a positive correlation and a clustered distribution in space,but also has a certain degree of correlation between plots;The high ecological niches of the evaluation results of cultivated land quality in An District overlap to a large extent,so the spatial distribution pattern of cold and hot spots of cultivated land quality in Xian’an District and its spatial heterogeneity characteristics are basically consistent with the overall changes in cultivated land quality.The model analyzes the relationship between the evaluation indicators of cultivated land quality and the quality of cultivated land in Xian’an District,and conducts spatial simulation calculation analysis.The quality of cultivated land is fitted and analyzed with 14 evaluation indicators.It shows that the construction of the evaluation index of cultivated land quality in Xian’an District is reasonable,and the evaluation results of cultivated land quality in Xian’an District are also reasonable.