Spatio-temporal response of ecosystem services to urban expansion in Jinan metropolitan area based on GTWR

  Objective  China’s urbanization development has entered a stage where the central cities lead the development of metropolitan areas and city agglomerations. How to promote the harmonious development of urbanization and the ecological environment in urban areas has become an important issue for high-quality urban development. Research about the spatio-temporal response of ecosystem services to urban expansion helps to characterize the spatial and temporal evolution of urban development and ecosystem services, promote the synergistic development of cities and ecosystems, and help formulate and implement sustainable planning strategies.

  Method  Taking Jinan metropolitan area as the target area, we studied the spatial and temporal characteristics of each city’s expansion based on the Urban Expansion Index calculation, evaluated the Ecosystem Service Value based on per unit area, and analyzed the temporal and spatial differentiation characteristics of ecosystem services. Furthermore, we studied the spatio-temporal response of ecosystem services to urban expansion of the Jinan metropolitan based on GTWR.

  Result  The results showed that: (1) From 1980 to 2020, urban expansion of the Jinan Metropolitan Area was characterized by time series and regional differentiation. The urban spatial expansion rate and intensity are sorted from high to low, small cities, large cities, megacities, and medium-sized cities. (2) The ecosystem services of the metropolitan area are decreasing year by year. The mainstream of the Yellow River and floodplain, Dongping Lake and its surrounding areas, and mountainous areas in central Shandong are important areas with high value of ecosystem services. The proportion of synergistic relationships in metropolitan areas is slightly lower than that of trade-off relationships, with megacities accounting for the highest proportion. (3) Urban expansion in the Jinan metropolitan area has a negative impact on ecosystem services, while the intensity of negative effects decreased year by year. The impact of urban expansion on the functions of ecosystem services of different subcategories was significantly different.

  Conclusion  We clarified the distribution pattern of spatio-temporal variation of urban expansion of different cities in the Jinan metropolitan area, and further analyzed the development state of gradual deterioration of ecosystem services during the study period. Based on the GTWR model, we quantified the different driving characteristics of urban expansion on ecosystem services at the spatial level. The results can provide a decision-making basis for the high-quality sustainable development of metropolitan areas.