Demarcation of Future Urban Rigid and Elastic Development Boundaries of the City of Haikou

Accelerated urbanization both promotes the rapid development of social economy and leads to a series of disadvantages, such as the excessive consumption of resources, environmental pollution, and food security threats. It is thus necessary to reasonably demarcate future urban development boundaries. Therefore, both the external supply and the elastic space of urban internal development need to be considered. In the present study, the current urban boundaries were first identified. Then, the urban rigid and elastic development boundaries in the next three decades were obtained by employing the minimal cumulative resistance (MCR) and CA-Markov models. Lastly, some suggestions were put forward for the implementation of future urban development boundaries. The results were the following. (1) The areas of the current urban boundaries of Haikou in 2000, 2010, and 2020 were 93.71, 124.26, and 260.41 km2, respectively. (2) By using the MCR model, the urban rigid development boundaries of Haikou in 2030, 2040, and 2050 were 361.27, 480.17, and 505.22 km2, respectively. (3) By using the CA-Markov model, the areas of urban elastic development boundaries in 2030, 2040, and 2050 were 381.86, 483.95, and 536.06 km2. (4) The increased elastic expansion space of urban development of Haikou while meeting the rigid constraint conditions in 2030, 2040, and 2050 was 20.59, 3.78, and 30.84 km2, respectively. (5) Suggestions need to be put forward on the implementation of future urban development boundaries from the aspects of technology, policy, and management. The results of demarcating the urban rigid and elastic development boundaries can not only prevent the excessive urban expansion and ensure the orderly, efficient and sustainable development of the city, but also more effectively protect important ecological resources, which could provide quantitative reference and decision-making basis for regional territorial space planning.