Spatiotemporal differentiation and driving factors of multi-functionality of land use in county scale in poverty belt around Beijing and Tianjin

Abstract: Multi-functionality of land use is of great significance to promoting regional sustainable development, which has become an important research topic in the field of land resources. In order to explore the spatiotemporal differentiation characteristics of multi-functionality of land use and its influencing factors, poverty belt around Beijing and Tianjin was taken as the study area in this paper. Three land use functions at county level (i.e., production function, living function, and ecological function) were identified and calculated quantitatively. Based on the concept of multi-functionality of land use, an indicator system was established, which was used to evaluate multi-functionality of land use in poverty belt around Beijing and Tianjin in 2000 and 2014 through the method of mean-squared deviation weight decision. The multi-functionality of land use was divided into five levels with natural break jenks, namely, the highest, higher, moderate, lower and lowest. Then, the characteristics of spatiotemporal differentiation of counties (districts) in the study area with different multi-functionality levels were determined. Meanwhile, spatial econometric models were used to identify the key factors that drove spatiotemporal differentiation of multi-functionality of land use. The results showed that: 1) the value of multi-functionality of land use in poverty belt around Beijing and Tianjin was between 0.208 and 0.564 in 2000 and 2014. There was significant spatial polarization in the multi-functionality of land use. Generally, the multi-functionality of land use in poverty belt around Beijing and Tianjin gradually emerged in a descending trend from west to east. The spatial patterns of multi-functionality of land use in the study area changed markedly from 2000 to 2014. The counties (districts) with higher multi-functionality of land use level expanded to Bashang Plateau and mountain areas on the edge of the plateau during 2000-2014. The counties (districts) with moderate level shrunk dramatically and moved toward the east, while the lower and lowest levels tended to be agglomerated in city border-regions. 2) The value of production function of land use ranged from 0.063 to 0.184 in 2000 and 2014 in poverty belt around Beijing and Tianjin. From 2000 to 2014, the spatial pattern of land use production function changed significantly in poverty belt around Beijing and Tianjin. The counties (districts) with the highest level of land use production function mainly spread from the administrative districts to their surrounding regions of Zhangjiakou city. The counties (districts) with higher level moved from the south to the north. The counties (districts) with moderate level moved towards the east, which were mainly distributed in Chengde city. Besides, the lower and lowest levels tended to be agglomerated in city border-regions. The spatial patterns of land use living function and ecological function in 2000 were basically in consistent with the spatial patterns in 2014. Some changes mainly took place in the administrative districts of Chengde city and the regions around the administrative districts of Zhangjiakou city. 3) According to the results of the spatial lag model (SLM), influencing factors of spatial differentiation of multi-functionality of land use tended to be diversified during 2000-2014. The spatiotemporal differentiation of multi-functionality of land use was influenced by national geographical environment, natural resource endowment, socio-economic factors and policy factors. Generally speaking, the spatial pattern of multi-functionality of land use was dominated by national geographical environment and natural resource endowment, which was also driven by socio-economic factors and policy factors. Finally, this study can provide scientific references for the sustainable use of land resources and the decision of land management in the future in the poverty belt around Beijing and Tianjin.