Objective A model simulating the land use of Qaidam Basin, Haixi Prefecture, Qinghai Province was established to decipher the driving forces for expansion and forecast future carbon storage in the region.

Methods The PLUS-InVEST model was input with the land use and cover changes (LUCCs) of the area in 1980, 2000, and 2020. Twelve factors including the annual average precipitation and temperature, soil type, digital elevation model, gradient, gross domestic product, and population, as well as the distances from waters, county government, highway, urban thoroughfare, and secondary road on the lands for different uses were analyzed. Past and projected LUCC expansions on the cultivated, forest-, grass-, wet-, construction, and virgin land types under the scenarios of natural development or prioritizing for farming conservation, urbanization or ecological protection were derived with a simulated 2040 LUCC for the basin.

Result (1) The major factors that drove the expanded land use in the area were soil type with an index of 0.18 on the cultivated land, distance from urban thoroughfare with an index of 0.35 on the grassland, annual average precipitation with an index of 0.26 on the wetland, distance from highway with an index of 0.24 on the construction land, and distance from urban thoroughfare with an index of 0.39 on the unused land. (2) The PLUS-InVEST model showed 2040 total land use expansions to be 4 080 km² for natural development, 156 km² for crop cultivation, 316 km² for urban development, and 3186 km² for ecological conservation. (3) The carbon storage in 2040, a significant increase from 2020 of 23.52×10⁵ t, was projected on the land for ecological preservation, while significant reductions would be experienced under all other development scenarios.

Conclusion The natural environment and traffic-related geographic location of a cultivated, grass-, wet-, construction or virgin land were the key driving forces of LUCC expansion at Qaidam Basin. LUCC expansion by natural development would surpass all scenarios in the 2040 projection. It would be followed by the emphasis on ecology, which would materially increase carbon storage on the land. Whereas urbanization and farming would level off, and protection of cultivated land stabilize with the implementation of proper management.