兴义市近二十年耕地时空演变分析

Analysis of the Temporal and Spatial Evolution of Cultivated Land in Xingyi City in the Past Two Decades

贵州省兴义市岩溶地貌占71.5%,丘陵占20.5%,平坝占7.2%,耕地属稀缺资源。因此,探明其耕地时空演变历程,可为发展和保护该地区农业资源提供重要参考。以兴义市2000—2020年期间每隔五年选一期,共五期耕地空间变化为研究对象,运用耕地丰度指数法、核密度分析法、空间自相关解析法等方法,构建耕地时空演变研究体系。研究结果表明:①兴义市耕地时空分布密集程度不均衡。在空间上,主要分布于东北和东南部,其中鲁屯镇和丰都街道分布最密集。在时间上,耕地面积2000—2005年增加,2005—2010年减少,2010—2015年增加,2015—2020年减少,时间分布变化幅度大,其中2015—2020年的变化幅度最大。②兴义市耕地地块集散中心变化较稳定,但地块数整体呈逐年递减趋势,其间由东北和中部向西北、南部递减。③兴义市耕地在空间中存在正相关性,即耕地空间分布呈集聚状态,体现在耕地面积比重的全局Moran's I值逐年增加。

In Xingyi City,Guizhou Province,karst landforms account for 71.5%,hills account for 20.5%,and flatlands account for 7.2%.Cultivated land is a scarce resource.Therefore,exploring the temporal and spatial evolution of its cultivated land can provide an important reference for the development and protection of agricultural resources in this region.This study took the spatial changes of cultivated land in Xingyi City in five periods,selected every five years from 2000 to 2020,as the research object,and used methods such as the cultivated land abundance index method,kernel density analysis method,and spatial autocorrelation analysis method to construct a research system for the temporal and spatial evolution of cultivated land.The results showed that:①The temporal and spatial distribution density of cultivated land in Xingyi City was unbalanced.Spatially,it was mainly distributed in the northeast and southeast,with Lutun Town and Fengdu Sub-district having the most intensive distribution.Temporally,the cultivated land area increased from 2000 to 2005,decreased from 2005 to 2010,increased from 2010 to 2015,and decreased from 2015 to 2020.The temporal distribution had a large variation range,with the largest variation range from 2015 to 2020.②The distribution center of cultivated land plots in Xingyi City was relatively stable,but the overall number of plots showed a decreasing trend year by year,decreasing from the northeast and central parts to the northwest and south.③There was a positive correlation in the spatial distribution of cultivated land in Xingyi City,that is,the spatial distribution of cultivated land was in an agglomerated state,reflected in the increasing global Moran's I value of the proportion of cultivated land area year by year.