Spatiotemporal Land-use Changes And Optimal Land Use Of Oasis City In Arid Areas

Oasis city, the economic growth pole of arid area, is the cluster center of human manufacture and life. Therefore, it is of great importance to have a systemic study of dynamic land-use change, its driving mechanism and optimal allocation, which in turn will benefit the sustainability of both local economy and land use.This study takes Kuytun City, the typical oasis city of Xinjiang, as a study case. Based on the interpretation of three-period TM/ETM+remote-sensing images from1993to2009, this thesis used various kinds of mathematical models, together with spatial analysis, landscape indexes, models, and statistics to have a comparative analysis on the16-year dynamic land use of Kuytun City, forecast its future land use, figure out the driving forces and finally put forward the optimal land-use allocation. Its main conclusions are as follows:(1) The characteristics of temporal and spatial land-use change:overall, the land use of Kuytun City varied with time and space. For its quantitative characteristics, the grassland decreased, while the cultivated land and construction land expanded; forestland increased significantly between2001and2009with a rising trend; and the waters and unutilized land changed a little with a reducing trend. For its spatial characteristics, great changes happened to the conversion among six land-use types; the downtown of Kuytun City, which lies on the east, developed with the main feature that construction land and forestland increased; and the Kaiganqi Countryside is with the feature of conversion between cultivated land and grassland. For its land-use landscape characteristics, the class area of land-use types is homogenizing, with their shapes aggregative, the overall landscape fragmentation, landscape diversity and heterogeneity increasing, and landscape agglomeration decreasing.(2) The land-use changes of Kuytun City is mainly driven by three main factors, like the natural factor, the eco-technologial factor and policy factor. Under the driving of these factors, the economic output, industrial structure, and the input and output of land changed accordingly. Such kind of changes directly or indirectly leads to the changes of land quanlity, land-use quantity, land-use structure and land-use degree, which will promote the changes of land-use patterns.(3) By combining the evaluation of land resources with the multi-objective programming model, this thesis established a multi-objective optimal model for Kuytun City, which will overcome the defects of the multi-objective linear programming. The result turns out that the out-coming of the optimal model meets the need of Kuytun City for economic development, social security and environmental protection. Besides, the comprehensive benefit of land use also increased, which fits the intended purpose. To ensure the optimal allocation, this thesis also put forward three land-use patterns-----eco-economic agricultural land use pattern, intensive low-carbon land-use pattern and ecological conservation land-use pattern.