Land Use Simulation and Landscape Ecological Risk Assessment on the Qinghai-Tibet Plateau

The land use and land cover pattern of the Qinghai-Tibet Plateau (QTP) is an important basis for the structure and function of the QTP ecological barrier. It is of great significance to simulate the land use pattern and landscape ecological risk of the QTP under future scenarios for the construction of the QTP barrier area and to promote the sustainable use of land resources. The QTP was selected as the study area. Based on the spatial pattern of land use in 2010 and 2020, the PLUS model was used to predict the land use patterns of the QTP in 2030 under the two scenarios of natural development and ecological conservation. The landscape ecological risk index was constructed to evaluate the past, present, and future landscape ecological risk of the QTP. The natural break point method was used to divide the landscape ecological risk index into five levels: lower ecological risk, low ecological risk, medium ecological risk, high ecological risk, and higher ecological risk. The results showed that: (1) Under the natural development scenario, the area of cropland, forestland, grassland, and unused land decreased continuously, while the areas of water and built-up land increased gradually. Under the ecological conservation scenario, the areas of forestland and grassland increased by 130 km(2) and 2293 km(2), respectively, compared with the natural development scenario. (2) Under the natural development scenario, the overall ecological risk of the QTP increased from 2010 to 2030, which showed that the proportions of lower ecological risk area decreased, while the proportion of medium and high ecological risk area increased. Under the ecological conservation scenario, compared with the natural development scenario, the area of lower, low, and high ecological risk increased by 4044 km(2), 2484 km(2), and 6401 km(2), respectively, while the areas of medium and higher ecological risk decreased by 6333 km(2) and 6597 km(2), respectively.