Delimitation of urban growth boundaries by integratedly incorporating ecosystem conservation, cropland protection and urban compactness

Urban expansion occupies open space at the city edge, most of which are ecological lands and cropland. Their losses cause far-reaching impact on ecological security and food security. The urban growth boundaries delimitation has been proposed to preserve these open spaces. Current studies consider ecosystem conservation or cropland protection independently, while largely ignore the potential trade-offs between them. This study aims to integratedly coordinate both ecosystem conservation and cropland protection by protecting superior ecological lands and cropland in the urban growth boundaries delimitation. The superiorities of ecological lands and croplands are treated equally for supporting urban expansion and are considered at the same time during land use simulation. Habitat quality (quantified by the InVEST model) and agricultural production potential are applied to reflect the superiority of ecological lands and cropland respectively. By applying a land use simulation model LANDSCAPE, the demand for urban land can be met by occupying inferior ecological lands and cropland. The urban growth boundaries can be thus delimitated accordingly based on the projected urban areas. The effect of urban growth boundaries delimitation can be reflected by the mitigated losses in habitat quality, agricultural production potential and change in urban compactness. Two scenarios are set up for comparing the effect of our approach. The result shows that our approach performs better in coordinating ecosystem conservation, cropland protection and a more compact urban morphology. This research contributes to a rational urban growth boundaries delimitation which integratedly incorporating ecosystem conservation, cropland protection and urban compactness.