沈阳市城市扩展与土地利用变化多情景模拟

利用基于遥感手段获取的沈阳市城市扩展与土地利用变化历史数据,对SLEUTH城市扩展模型进行校正,对未来(2005~2030年)不同管理情景下的城市扩展与土地利用变化过程进行模拟,并对其发展变化趋势和生态环境影响进行分析与比较。结果显示,在三种管理情景下,未来的沈阳市城市建设用地都将持续增加,大量的耕地资源被侵占;但不同管理情景下,城市景观格局和区域面临的景观生态风险却表现出明显差异。SLEUTH模型的模拟结果较好地反映了沈阳市不同土地利用政策、规划方案等对未来城市扩展和土地利用变化以及区域景观生态风险的潜在影响,同时也指出了当前城市增长管理政策中存在的不足之处。

Research for scenarios simulation of future urban growth and land use change in Shenyang City

SELUTH urban growth model was used to simulate the process of future urban growth and land use changes, and to explore potential environmental impacts of urban development under different policy scenarios in Shenyang city. The SLEUTH model was calibrated with historical data (1988~2004) extracted from a time series of TM satellite images, and the future growth was projected out to 2030 assuming three different urban growth management scenarios: (1) current trends development scenario (Scenario CT), (2) urban planning and regional development scenario (Scenario PP) , and (3) eco-environmental protection management scenario (Scenario EP), Scenarios analysis showed that Shenyang City would be faced with sustaining urban expansion, and large amounts of farmland would be occupied by urban land under all policy scenarios. But, the patterns of urban landscape and regional landscape ecological risks resulting from urban growth would show significant differences under different policy scenarios. Under Scenario CT, urban growth area would add up to 277.0 km², of which 224.8 km² would result from the conversion of farmland to urban land. And urban development pattern would be relatively dispersed and complex, which could result in relatively high landscape ecological risk under no management. Under Scenario PP, urban land showed relatively low growth rate and urban development pattern would be more dispersed with higher landscape ecological risk than Scenario CT. Under Scenario EP, urban expansion would concentrate on existing urban land and show compact development pattern with relatively low regional landscape ecological risk. Simulation results from SLEUTH model gave good expression for the potential affects of different land use policies and urban planning scenarios on future urban growth and land use changes and landscape ecological risks. Simultaneously, these results pointed out the disadvantages of current management policies for urban growth in Shenyang City. In the process of implementation of current urban planning scenario and regional development policy, the government should pay more attention to optimization of urban spatial pattern and protection of farmland from urban expansion. And, it was necessary to take stringent environmental protection measures, to encourage compact urban growth, and to enhance intensive use of the existing land resources in future urban growth management of Shenyang City.