Multi-scenario Simulation of Land Use and Ecosystem Service Value in Ecological Transition Zone: A Case Study of Gansu Province

Gansu Province, a typical arid and semi-arid ecological transition zone, serves as a key ecological shield in China. The ecological and environmental protection of Gansu plays a vital role in establishing an ecological barrier in northwestern China. Therefore, investigating future changes in land use and ecosystem service value (ESV) in Gansu under multiple scenarios is essential to inform the development of ecological and environmental protection measures. Such studies hold significant value for optimizing the spatial pattern of land use in this ecological transition zone. In this study, changes in land use in Gansu were analyzed using various methods, including the land use transfer matrix, based on land use data from 2000, 2010, and 2020. The future land use demand and spatial distribution in Gansu for 2030 were predicted using the Patch Land Use Simulation Model (PLUS Model), incorporating a planning intervention scenario. This scenario was based on conventional natural evolution, economic development, ecological protection scenarios, and the mandatory constraints of Gansu's land spatial planning. Additionally, the equivalent factor method was applied to calculate the ESV of Gansu in 2020 and in the future under four future scenarios. Our findings reveal the following: (1) Between 2000 and 2020, land use in Gansu was predominantly grassland and unused land (mainly deserts such as the Gobi Desert), both accounting for over 30%. Land use changes were characterized by mutual transition between "forest-field-water-grass-sand". (2) Under the economic development scenario, the area of construction land showed the largest increase (36.29% from 2000 to 2020). Under the ecological protection scenario, the area of grassland experienced the largest increase (1 790.23 km² from 2000 to 2020). In the planning intervention scenario, construction land increased by 19.90%, while grassland expanded by 1 469.47 km². (3) The ESVs under the natural evolution, economic development, ecological protection, and planning intervention scenarios were 370.447 billion yuan, 369.808 billion yuan, 373.014 billion yuan, and 372.556 billion yuan, respectively. The planning intervention scenario effectively balances the needs of economic development, food security, and ecological protection in terms of land use. The Gansu government should thus focus on the spatial and temporal variations in land use functions and prioritize the protection and restoration of critical ecological source areas, such as protective forests in the Hexi Corridor, Qilian Mountain National Park, and water conservation zones in the Yellow and Yangtze River basins.