Multi-scenario simulation of land use change based on the objectives of cultivated land, ecological protection, and economic development in Yunnan Province, China

Land use change scenario simulation based on multi-objective synergy can provide a scientific basis for coordinating ecological protection, resource management and economic development by quantitatively analysing and predicting the dynamic evolution of land use. As an ecological security barrier and cross-border opening frontier in southwest China, Yunnan Province is characterised by "mountainous and cross-border" land use change, which poses a multidimensional challenge to the sustainable development of the region. Based on the land use data from 2000 to 2020, coupled with the improved Markov FLUS model and multi-source driving factors, this study takes Yunnan Province as the study area. To simulate the land use pattern in 2040 under four scenarios, namely natural development, ecological protection, economic priority and cultivated land protection, and to reveal their evolution patterns and driving mechanisms. The study shows that: (1) between 2000 and 2020, cultivated land decreased by 1405.05 km² (-1.98%), of which 58% was converted to architecture after 2010, with the loss of high quality cultivated land concentrated around the urban agglomeration of central Yunnan (Kunming and Qujing); forest land showed a "decrease and then increase" trend (net increase of 0.84%) due to the intervention of ecological policies; architecture increased by 133.54%, but there was an abnormal decrease (-411.67 km²) from 2010 to 2015 due to the stock renewal policy. Forest land showed a "decrease and then increase" trend due to ecological policy interventions (a net increase of 0.84%); architecture increased by 133.54%, but paradoxically contracted between 2010 and 2015 (-411.67 km²) due to the stock renewal policy. (2) Multi-scenario modelling shows that under the economic development scenario, the cross-border economy, while driving the rapid development of the border crossing zone, may lead to the problem of underutilised land, and at the same time increase the risk of damage to ecological protection zones; The new cultivated land in the cultivated land protection scenario is located in the mountainous areas of northeastern Yunnan, exposing the governance dilemma of 'occupying the best and making up for the worst'; Forest and grassland in the north-western mountainous areas of the ecological priority scenario have been effectively protected and restored, but the pressure on cultivated land has increased, exposing the deep-seated contradiction between ecological conservation and food security. (3) The study proposes a framework for zoning control and differentiated management, delineating 'core control areas - ecological protection areas - special development areas', and enforcing rigid rules such as 'updating the stock' and 'occupying the optimal area to make up for the optimal one'. Rigid rules. Through the model improvement of dynamic weighting of terrain gradient, cross-border economic factors and cultural constraints, the simulation accuracy of the complex border environment is improved, which can provide scientific reference for the optimisation of land use in the global mountainous and cross-border regions.