Evolution of water-carrying capacity and response law of land space pattern in the Three Gorges Reservoir Area

Coordination between carrying capacity of water systems and socioeconomic development can effectively support orderly socioeconomic development. To comprehensively examine the interaction between socioeconomic development and water in the Three Gorges Reservoir Area (TGRA), an assessment system of the water-carrying capacity (WCC) and land space pattern (LSP) was constructed. A coupling coordination model and redundancy analysis were employed to examine the coordination index and driving mechanism between the water-carrying capacity and the urban, agricultural, and ecological function indices (UFI, AFI, EFI) respectively in the TGRA. The WCC exhibited an overall increase from 2005 to 2018, with 76.92 % of the districts surpassing the moderate level in 2018. The coordination between UFI and WCC displayed a trend of initially rising and then slightly declining over time, with minimal spatial variation. The coordination between AFI and WCC showed a slow upward trend, whereas that between the EFI and WCC was higher than that between UFI and AFI. The key factors influencing the coordination between different land spaces and WCC varied considerably over time. From 2005–2018, urban spatial expansion, economic growth, and water environmental capacity were identified as the key influencing variables for urban functional areas. Regarding ecological functional areas, factors such as ecological space occupancy, habitat quality index, and water ecological parameters demonstrated strong synergistic effects. From 2005–2010, water availability and consumption played a significant role in synergistic coordination, whereas in 2018, ecological factors such as forest cover and capacity for water conservation emerged as prominent variables for agricultural function areas. In view of these analyzed results, some potential strategies for the sustainable management of water resources, such as optimizing urban boundaries, improving water use efficiency, centralizing rural residences, strengthening agricultural pollution controls, and considering the impact of vegetation changes on the hydrological balance were suggested to better coordinate future areal water-land space patterns relationships.