Abstract:

【Objective】 The Suzhou-Wuxi-Changzhou metropolitan area is one of the three major metropolitan areas in Jiangsu Province and a core area of the Yangtze River Delta, China. Since the 1980s, the urbanization in the Suzhou-Wuxi-Changzhou metropolitan area has been drastic, where regional ecological problems urgently require attention. The blue-green space provides the basis to construct a regional ecosystem. Quantitatively characterizing the evolution of these spaces provides a basis to plan the spatial configuration of the Suzhou-Wuxi-Changzhou metropolitan area in an ecologically conscious manner.【Method】 Using remote sensing images from 2003, 2008, 2013 and 2018, the dynamic change model and landscape pattern index were used to analyze the evolution of the scale and landscape patterns of blue-green space in the Suzhou-Wuxi-Changzhou metropolitan area and its member cities over the recent 15 years.【Result】 (1) From 2003 to 2018, the change in blue-green space in the Suzhou-Wuxi-Changzhou metropolitan area was -3.52%; the green space changed drastically, while the blue space was relatively stable. The blue and green spaces changed from a “decreasing period” to an “increasing period”. (2) At the class metrics level, the fragmentation of blue space in the Suzhou-Wuxi-Changzhou metropolitan area decreased, while its complexity and connectivity increased. By contrast, the fragmentation and complexity of green space increased, and its connectivity decreased. The diversity of blue-green space decreased at the landscape level, while connectivity and aggregation increased. (3) During the study period, changes in blue-green space in each member city were similar to those in the metropolitan areas. Changzhou experienced the highest degree of dynamic change, Wuxi experienced the smallest; the blue-green space of Changzhou showed higher fragmentation and complexity, and the landscape pattern changed more drastically. Suzhou experienced low diversity, high connectivity, and aggregation in blue-green space.【Conclusion】 Over the past 15 years, the scale and landscape patterns of blue-green space in the Suzhou-Wuxi-Changzhou metropolitan area have changed significantly, with clear differences between cities. As such, there is a need to systematically plan and protect the regional ecological environment in this area.

Key words: blue-green space, spatial-temporal evolution, landscape pattern, Suzhou-Wuxi-Changzhou metropolitan area