Spatio-temporal variation and dynamic scenario simulation of ecological risk in a typical artificial oasis in northwestern China

Landscape ecological risk assessments have played a critical role in measuring and predicting the quality and dynamic evolution of the ecological environment. In this study, a typical artificial oasis in the Alar reclamation area of Northwest China was selected as the research area. We acquired Landsat images from the past 30 years for the study area. Based on these remote sensing images, continuous long-term series and multi-temporal syntheses were combined to classify and construct a landscape ecological risk index. Our results showed a clear downward trend in the overall ecological risk in the Alar reclamation area between 1990 and 2019. Through scenario simulation, we found that the ecological risk of the research area is predicted to decrease in 2025 and 2030 under the two scenarios of natural growth and strict government control. Compared to the natural growth scenario, the increased area of construction and cultivated land is predicted to be less under the government control scenario, which contributes to the decrease in the overall ecological risk. Therefore, when formulating the overall plan for land use, the government should strictly control the increase in construction and cultivated land and prohibit illegal cultivation and blind reclamation of cultivated land. We used a classification method that is more suitable for the local study area, thereby increasing classification accuracy, and in turn, simulating and evaluating future landscape patterns more accurately. Our study provides a good reference for similar studies to be conducted in arid regions of northwest China and around the world.