西南山地城市耕地时空变化及其驱动力研究——以重庆市沙坪坝区为例

Research on Spatial Temporal Variation and Driving forces of Cultivated Land in Southwest Mountainous Cities——A Case Study of Shapingba District of Chongqing

本研究结合2005年、2009年、2015年遥感影像图与变更调查成果,利用主成分与多元回归分析相结合的方法,分析耕地的时空变化特征及其主要驱动力,结果表明:沙坪坝区耕地时空变化特征显著,耕地面积与人均耕地面积呈现快速减少后趋于平稳的总体趋势;耕地变化呈现出明显的空间差异性特征,从变化强度来看,西南部区域为高度变化区,北部区域为中度变化区,中部及东部区域为低度变化区;从耕地相对变化量来看,虎溪街道耕地变化速率最快,最慢的为覃家岗街道;2005—2015年,沙坪坝区耕地重心向东北方向偏移明显,偏移距离达1 302.48m;主成分分析表明,影响沙坪坝区耕地时空变化的驱动因子可归纳为社会经济发展水平和农业结构调整,其中社会经济发展水平是最主要因子;多元回归分析表明社会经济是影响沙坪坝区耕地时空变化的最主要驱动力。研究结果能为耕地资源的合理开发与规划利用提供理论指导与实践借鉴。

Based on the land changing surveys and remote sensing image of the Shapingba Dis- trict, Chongqing, this study uses principal component analysis in combination of the multiple regres- sion analysis method to analyze the spatio-temporal variation of cultivated land and its driving forces. The results are as follows. First, the spatio-temporal variation of cultivated land in the Shapingba District is remarkable, cultivated area and per capita cultivated area present an overall trend of rapid decrease and then gradually flattens out. Second, the cultivated land variation demonstrates a signifi- cant character of spatial difference. For varied intensity, the southwest part is high level varied area, the north part is medium level varied area, the middle and east part are low level varied areas. For rel- ative variation, Huxi street owns the fastest rate of change while Qinjiagang street owns the slowest. Third, from 2005 to 2015, the orthocenter of cultivated land in the Shapingba District distinctly deviated towards northeast, the distance reaches 1302.48m. The principal component analysis indicated that socioeconomic development level and adjustment of agricultural structure factor can be summed up as the two main factors to reducing cultivated land in the Shapingba District and the socioeconomic devel- opment level is the key factor. Multiple regression analysis indicated that the economic factor is the key driving force. These results will provide theoretical guidance and practical reference for the rational exploitation, utilization and planning of cultivated resources.