城镇化进程中耕地时空格局演化及其驱动机制研究——以扬州市为例

Spatiotemporal Pattern Evolution and Driving Mechanism of Cultivated Land in Urbanization Process——Taking Yangzhou City as an Example

快速城镇化导致我国的耕地面临数量持续减少、质量不断下降的风险,而中小城市在这方面的表现尤为突出,研究中小城市的耕地资源动态变化规律以及时空演变趋势,对经济高质量发展形势下的耕地高质量使用与管理、生态保护和资源协调发展等意义重大.运用ArcGIS空间分析与经济计量分析方法,研究并揭示2000-2020年扬州市耕地时空演化的特征,选用增强回归树(Boosted Regression Trees, BRT)算法分析了地理空间、社会及经济层面13个潜在驱动力因子对耕地变化的影响.结果表明,(1) 2000-2020年扬州耕地净流失面积在不断扩大,耕地流失较为严重的区域集中在扬州市区及3个区县的周边乡镇.(2)减少耕地的主要去向是建设占用,且占用耕地主要分布在扬州的主城区及下辖县(市)城区的周边,耕地的连片整体性受到不断破坏,破碎化的趋势有不断增加的趋势.(3)扬州耕地变化的时空特征是地理空间和社会经济因素综合作用的结果. 2000-2020年扬州耕地的变化受经济因素的驱动作用明显,特别是2005-2010年时段,耕地变化受人均GDP影响较大,而受自然因素的影响非常有限.在新时代经济高质量发展形势下,扬州市需要转变城镇发展用地的使用模式,要从粗放式扩张向挖掘自身潜力转变,要避免建设用地对优质良田的无序占用,要进一步探索全市范围内耕地使用、生态空间保护的补偿机制,为同类城市耕地高质量使用与管理提供借鉴.

The rapid urbanization process has led to the continuous decrease in the area of cultivated land and the increase in the risk of land quality decline in China,especially in small and medium-sized cities.It is of great significance to study the dynamic change law and spatiotemporal evolution trend of cultivated land resources in small and medium-sized cities for the high-quality use and management of cultivated land,ecological protection and coordinated development of resources under the situation of high-quality economic development.ArcGIS spatial analysis and econometric analysis method were used to study and reveal the spatiotemporal evolution characteristics of cultivated land in Yangzhou from 2000 to 2020.Boosted regression tree algorithm was used to analyze the effects of potential driving forces of 13 factors at the geographical,social and economic levels on the change of cultivated land.①In the past 20 years,the net loss area of cultivated land in Yangzhou has been expanding,and the regions with serious loss of cultivated land were concentrated in the urban area of Yangzhou and the surrounding towns of the three counties.②The main direction of reducing cultivated land was construction occupation,and the occupied cultivated land was mainly distributed in the main urban area of Yangzhou and the surrounding areas of the subordinate counties(cities).The integrity of cultivated land was constantly destroyed,and the trend of fragmentation was increasing.③The spatiotemporal characteristics of cultivated land change in Yangzhou were the result of the combined effect of geographical space and socio-economic factors.The change of cultivated land in Yangzhou from 2000 to 2020 was obviously driven by economic factors,especially from 2005 to 2010.The change of cultivated land was greatly influenced by per capita GDP,while the influence of natural factors was very limited.Under the situation of high-quality economic development in the new era,Yangzhou needs to change the use mode of urban development land from extensive expansion to explore its own potential,to avoid the disorderly occupation of high-quality farmland by construction,and further explore the compensation mechanism of differentiated use of cultivated land and ecological space protection in the whole city,so as to provide reference for the high-quality use and management of cultivated land in similar cities.