Abstract:

Under the background of rapid urbanization in the Qinhuai River Watershed, models of land use change are primary tools for analyzing the causes and consequences of land use changes. We choose CLUE-S model to simulate the land use situation of it in 2020. We use linear regression model, Markov model and the gray GM (1, 1) model respectively to predict the demand for land use which is needed by the non-spatial module of CLUE-S model, then we compared the three forecast results.In order to further verify the influence of policy on land use change, two prediction scenarios were established, one is "natural development" scenario where land use will change according to historical trend and the other is "optimization" scenario which considered the effects of planning policy. We simulated the Qinhuai River Watershed land use pattern in 2020 under different scenarios, and analyze the landscape pattern of it. The results shows that the Kappa index of Linear regression model, Markov model, the gray GM (1, 1) model are 0.866, 0.849, 0.867 respectively, so three methods all satisfy the requirements of model accuracy; In “natural development” scenario, the water area, paddy field, forest land, urban land and the dry farm change, compared to 2010, by 21.5%, 15.3%, 9.0%, 9.0%, 9.0%, respectively, while in “optimization” scenario water area, paddy field, forest land, urban land and the dry farm change by 3.1%, 1.6%, 10.8%, 6.3%, 10.8%, respectively; Under the “optimization” scenario, the land use condition can meet the requirement of protection of basic farmland and ecological land, increasing infiltration capacity of rainwater, and alleviating the urban heat island effect. This work could be the reference for the choice of the method of non-spatial module and provide scientific support for land use planning and managements of the watershed.

Key words: land use simulation, CLUE-S model, Non-space module, scenarios simulation, the Qinhuai River Watershed