Evaluation and practice of urban construction suitability in coastal volcanic areas of southeast China: a case study of Ningde City, Fujian Province

The suitability of urban construction is an important element in evaluating resources and environment carrying capacity and suitability of national land utilization, and also a basis for national spatial planning and management. Based on the "Double Evaluation" guidelines, an evaluation system for the suitability and potential of urban construction was set up for Ningde City, one of the coastal volcanic areas in southeast China, and relevant suggestions on future development direction and pattern of the city were put forward. The results show that the suitable zone for urban construction in Ningde covers an area of 2 682.88 km², accounting for 19.98％ of the total regional land; while the unsuitable zone covers an area of 5 979.06 km², accounting for 44.53％. Due to the typical geomorphology of the volcanic area, the suitable areas for urban construction in the region is poor in contiguity with relatively scattered distribution, while the contiguity of the suitable zone for granite area urban construction is better. The distribution characteristics and contiguity of the suitable areas are generally controlled by the topographies and geomorphological patterns of different lithology, with obvious differences among counties (districts and cities). There are more ecological function types land in the potential area including rural residential land, tea plantations and orchards, all of which constitute the potential for urban expansion and construction. It is suggested to strengthen "developing along the east and advancing westward" as a future development direction, and that the urban development pattern of "one core-three axes-multiple clusters" should be formed to achieve a coordinated development situation among the mountains and the sea.