The impact of policies on land use and land cover changes in the Beijing–Tianjin–Hebei region in China

The Beijing–Tianjin–Hebei (BTH) region has experienced unprecedented growth in population, economy and urbanisation in recent decades, in which a great deal of non-urban construction land have been transformed into urban construction. Researching the dynamics of land use and land cover (LULC) change is essential for formulating land regulation policies. This paper systematically quantifies changes in LULC in the BTH region from 1980 to 2015, and then deeply analyses the influence of both land regulation policies and spatial development strategies on these changes. The main discoveries of this research are: (1) The primary change in LULC is the conversion from agricultural land to construction land, and the secondary is from agricultural land to ecological land; The eastern and southern parts of the BTH region became the hotspots of LULC changes, while the western and northern parts became the cold spots of LULC changes; The centroids of construction land have been moving towards Beijing and Tianjin since before 1995. However, the direction of movement of the centroids has become divergent since 1995. For ecological land, the centroid moved eastwards before 2000, and then westward after 2010. (2) Land regulation policies have restricted the conversion of agricultural land to construction land, and they have made enormous contributions to the conversion of agricultural land to ecological land in most of the periods, especially from 2010 to 2015, when 3613.35 km2 of agricultural land were converted into ecological land due to a series of land regulation policies. The spatial development strategies have weaken the effect of the construction land agglomerated to the Beijing and Tianjin Municipalities, and promoted the construction land more divergence distribution in the BTH regions. The research results can significantly enhance farmland protection programs, and ecological land planning, which are crucial in the face of the growing demand for construction land.