Assessment of the Natural Carrying Capacity of Harsin Urban Growth Using CA-Fuzzy Hybrid Models

Urban carrying capacity encompasses various dimensions, one of which is natural carrying capacity. This concept addresses the extent to which urban development aligns with environmental capacities and how a city can utilize its natural potentials up to a sustainable threshold, which exemplifies a movement toward sustainable development. Accordingly, determining the natural capacity of urban growth is considered one of the fundamental principles of urban sustainability. In this regard, Harsin city in Kermanshah province, selected as the case study of this research, has experienced population migration to its peripheral areas in recent years, imposing excessive natural pressure on these zones. Therefore, the main objective of this study is to assess the natural carrying capacity for the future growth of Harsin. The research method is descriptive-analytical and applied in terms of objective. Landsat satellite imagery from three periods (1985, 2000, and 2021) was utilized, and the relevant layers were processed in GIS and Idrisi software using an integrated Markov Chain and Cellular Automata (CA) approach to predict future land-use changes and determine high-potential zones for future urban growth. The results of change detection indicate that Harsin has expanded by approximately 314 hectares during the studied period (1984–2021). While the area of Harsin was only 235 hectares in 1984, it increased to 549 hectares by 2021. In terms of natural substrate carrying capacity, the northern and southern directions are entirely unsuitable for the city’s expansion, and any growth in these directions would lead to numerous natural crises. The city can only expand in the east-west direction, a pattern that guides the urban form toward a linear structure.