Abstract: Taking the Ili River Valley in Xinjiang as an example, the trade-off and synergy dynamics of land use functions from 2000 to 2020 were explored at the grid scale and the zoning of land use functions was carried out by Geographically Weighted Regression (GWR) and the Self-Organizing Feature Map (SOM) network. The results showed that the production function and living function of land use in the Ili River Valley were significantly enhanced, extending from the urban area to the outside. The ecological function decreased first and then increased, with higher values predominantly concentrated in the southern and northern mountainous regions characterized by favorable natural environmental conditions. The interactions among different land use functions demonstrated notable spatio-temporal heterogeneity. Specifically, the production-living function relationship was primarily synergistic, though the strength of synergy had gradually diminished over time; in comparison, the production-ecological and living-ecological relationships were predominantly characterized by trade-offs, with their intensities first increasing and then decreasing. A comprehensive zoning scheme from grid scale to township scale was constructed. Finally, five functional areas were formed at the township scale, including the key development area of production function, the moderate development area of living function, the core conservation area of ecological function, the important maintenance area of composite function and the potential improvement area of comprehensive function. Based on regional resource endowments, appropriate optimization suggestions were proposed for different functional areas to provide scientific reference for land space planning in arid and semi-arid areas.

Key words: land use functions, trade-offs/synergies relationship, time and space evolution, zoning optimization, Ili River Valley