Spatial Differences of Coastal Urban Expansion in China from 1970s to 2013

As the ′economic engines′ of China,coastal cities have developed and expanded considerably since the 1970 s.In this study,information on the urban expansion process of Chinese coastal cities from the 1970 s to 2013 was retrieved.Through the analysis of stage characteristics,spatial expansion modes,influences on land use,centroid shifts,and spatial morphological evolutions,the spatial differences of coastal urban expansion were revealed.Results indicate that 1) the expansion stages of southern coastal cities are more complex than those of northern coastal cities,and the expansion ranges and speeds of the former are far higher than those of the latter;2) the spatial expansion of southern coastal cities mostly adopt a single mode,whereas northern coastal cities mostly adopt a mixed mode;3) significant spatial differences in the occupations of different land sources exist between the south and the north along the coastline;4) the centroid of coastal cities tends to migrate toward the coastline,and the centroid shift distances of southern coastal cities are clearly higher than those of northern coastal cities;and 5) the spatial morphology of southern coastal cities tends to be compact,whereas that of northern coastal cities tends to be loose.Policies have a powerful significance in terms of guiding urban expansion and its spatial differences in coastal cities.Urban expansion in coastal cities will encounter new opportunities and challenges under the guidance of new types of urbanization strategies.

Spatial expansion effects on urban ecosystem services supply-demand mismatching in Guanzhong Plain Urban Agglomeration of China

Global urbanization has led to drastic land use change,interfering the ecosystem services(ES)supply-demand balance,in turn threatening the well-being of humans.However,existing studies mainly stranded at the historical and current analysis,and the effects of urban spatial expansion on the relationship between ES supply and demand in the future are less clear,in particular at an urban agglomeration scale.This study was constructed with a framework of assessing the effects of urban spatial expansion on ES supply-demand mismatching under different future scenarios in the Guanzhong Plain Urban Agglomeration(GPUA)by using the Future Land Use Simulation(FLUS)model and expert-based Land-Use and Land-Cover Change(LUCC)matrix.The results showed that:(1)Urban expansion is significant in the natural development(ND)scenario,mainly manifesting the great transfer of dry land to construction land.(2)The gap between total ES supply and demand is narrowed from 2000 to 2030 and the mismatch between ES supply and demand is mainly reflected in the spatial distribution pattern in the GPUA.The ES budgets were in high surplus in Northern Qinling Mountains and northeast mountain areas,while they were in severe deficit in urban center areas.The budgets deficit under the ND scenario in 2030 is the most severe.(3)The gradient differences of ES budgets of the GPUA between urban centers and suburbs increase from 2000 to 2030 under two scenarios.The deficit region expands largest under ND scenario.The findings revealed that ES declining and supply-demand mismatching were triggered by the drastic land-use change driven by rapid urban expansion.The expansion has brought about an increasing material demand and growing industries,threatening the sustainability of ecosystems.Scenarios setting could contribute to coordinating the relationship between future urban development and ecological protection,and the policy strategies proposed in the study could inform ecological management and urban planning in the regions facing the similar urbanization situation.