京津冀地区耕地利用转型时空分异及驱动机制

耕地利用转型代表耕地利用形态的趋势性变化。论文以京津冀地区157个县域空间为基本研究单元,从显性形态与隐性形态双重属性出发构建耕地利用形态指标体系,运用冷热点、空间变差函数等方法分析1990—2015年耕地利用形态变化的时空特征,在此基础上,利用空间误差模型(spatial error model, SEM)对耕地利用转型的驱动机制进行了定量分析。结果表明：① 京津冀地区耕地利用形态指数空间分布呈东南高、西北低的格局,与该地区地形分布格局基本一致,且因坝上高原特色农业发展形成独立高值区。② 京津冀地区耕地利用形态指数空间分异呈现逐渐缩小的趋势,显著热点区与显著冷点区分布相对稳定且面积不断缩小,耕地利用转型较为平稳。显性形态值普遍呈现先升高后降低趋势,隐性形态值则呈升高趋势,表明京津冀耕地出现空间收缩、功能优化式转型。③ 高程是影响京津冀地区耕地利用形态空间特征的主要自然环境因素,二三产业占比、地均固定资产投资与城镇化率等经济发展和城镇建设因素则是驱动1990—2015年京津冀地区耕地转型的主导因素,但不同时段、不同县域单元耕地转型动力机制存在差异,各驱动因子作用强度也不完全一致。

Spatiotemporal characteristics and dynamic mechanism of cultivated land use transition in the Beijing-Tianjin-Hebei region

The transition of cultivated land use represents the change trend of cultivated land use form. Taking 157 counties in the Beijing-Tianjin-Hebei region as cases, this study constructed the index system of cultivated land use form from the dual attributes of dominant form and recessive form. The spatial and temporal characteristics of change of cultivated land use form were analyzed by the methods of cold/hot spot analysis and spatial variation functions. On this basis, the driving mechanism of cultivated land use transition is quantitatively analyzed by the spatial error model (SEM). The results show that: 1) Cultivated land use form index values in the Beijing-Tianjin-Hebei region is high in the southeast and low in the northwest, which is consistent with the terrain distribution pattern in the region. Due to the development of characteristic agriculture on the Bashang Plateau, an independent high-value area was formed. 2) The spatial differentiation of cultivated land use form index in the Beijing-Tianjin-Hebei region shows a trend of gradual reduction. The distribution of significant hot spots and significant cold spots is relatively stable and the area continues to shrink, which indicates that the transition of cultivated land use is relatively steady. Specifically, the dominant morphological value generally increases first and then decreases, while the recessive morphological value increases, demonstrating that the cultivated land in the Beijing-Tianjin-Hebei region is undergoing spatial contraction and functional optimization transitions. 3) Elevation is the main natural environmental factor that affects the spatial characteristics of cultivated land utilization, while the economic and urban development factors such as the proportion of secondary and tertiary industries, average fixed asset investment, and urbanization rate are the leading factors driving the transition of cultivated land in the Beijing-Tianjin-Hebei region from 1990 to 2015. However, there are differences in the dynamic mechanism of cultivated land use transition in different time periods and different county units, and the intensity of each driving factor is also different.