Ecological carrying capacity assessment

Ecological carrying capacity (ECC) is central to assessing the sustainability of ecosystems, aiming to quantify the limits of natural systems to support human activities while maintaining biodiversity and resource regeneration. To assess ECC, earlier studies typically used the analytic hierarchy process (AHP) method for modeling. In this study, we developed an AHP-EW method based on a combination of AHP and entropy weight method, which considered important indicators including land use, vegetation, soil, location, topography, climate, and socio-economics, and constructed an ECC evaluation system. The new AHP-EW method was applied to analyze the spatiotemporal ECC patterns in Urumqi from 2000 to 2020. The results showed a general decreasing trend in ECC during the period 2000-2020. Among them, the ECC decreased significantly by 19.05% from 2000 to 2010, while after 2010, the decrease slowed down to 14.12%, owing to the implementation of ecological conservation policies. In addition, Midong District, Dabancheng District, and Urumqi County had worse ECC. Still, in general, the distribution of ECC in each district and county showed a trend of decreasing in areas with low ECC and increasing in areas with high ECC. Cluster analysis showed that ECC improved in ecological reserve areas, while some built-up areas showed a decrease in ECC due to economic development and human activities. Driving factors analysis shows that NDVI, climate change, and land use conversion are the key factors influencing the change of ECC in Urumqi. This study provides new ideas and technical support for ECC assessment in the global arid areas, which can help formulate more effective ecological protection strategies and promote the healthy and stable development of regional ecosystems.