顾及土地生态安全的环鄱阳湖城市群土地利用情景模拟

在国家大力推进新型城镇化和落实城市群空间规划的背景下,评价城市群土地生态安全水平,并以此为限制条件预测城市群未来土地利用格局,对城市群可持续发展具有重要意义。本文以环鄱阳湖城市群为研究对象,对城市群土地生态安全格局和变化进行分析,根据土地生态安全评价结果设置自然发展情景和生态保护情景,结合多分类Logistic回归和多标准评价方法(MCE),构建CA-Markov模型,预测2种情景下2030年土地利用格局并进行对比分析。研究结果表明:①2005、2010和2015年,环鄱阳湖城市群网格平均生态安全值分别为0.574、0.573和0.571,空间布局上呈现"中部低、东西高"的特征;②预测2030年,自然发展情景下新增城镇用地主要位于九江市、上饶市和南昌市,生态保护情景下限制城镇用地和其他建设用地向土地生态安全高值区扩展,使得城镇用地和其他建设用地扩展更加集中;③预测生态保护情景下,高生态安全区面积比自然发展情景下多39.39%且分布更加均匀,包括鄱阳湖周边区域、九江市中部以及新余市和吉安市,城市群生态安全得到有效保护。该研究可为环鄱阳湖城市群土地利用规划及生态保护提供参考。

Land Use Simulation of the City Clusters Around Poyang Lake based on Land Ecological Security Assessment

As China has been vigorously promoting the new-type urbanization and implementing spatial planning policies, city clusters have become the urbanization frontier. But the contradiction between economic development and ecological protection restricts the sustainable urbanization. As the basis of urban development, the changes of land quantity and distribution have a significant impact on the structure and functioning of ecosystem. Therefore, land ecological security assessment of city clusters and predicting future land use patterns of city clusters based on such an assessment are crucial to the sustainability of city clusters. The assessment of land ecological security is the basis of the optimal allocation of land resources, and land use simulation is an important method to predict the trend of land use changes. Combination of the two methods can provide reference for optimizing land use patterns and protecting the eco-environment. By studying the city clusters around Poyang Lake, this paper analyzed land ecological security patterns and changes of the city clusters. Based on the results of land ecological security assessment, the paper set up the business-as-usual scenario and the ecological protection scenario. By combining the multinomial logistic regression and Multi-Criteria Evaluation method (MCE), the paper constructed the CA-Markov model to predict land use patterns in 2030 under the two scenarios, and conducted comparative analyses. Results show: (1) In 2005, 2010, and 2015, the average ecological security of the city clusters around Poyang Lake were 0.574, 0.573, and 0.571, respectively. The security level were low in the middle and high in the east and west in the spatial layout. (2) In 2030, the newly developed urban lands under the business-as-usual scenario will mainly occur in Jiujiang, Shangrao, and Nanchang. Under the ecological protection scenario, the lands for constructing towns and other construction purposes will be restricted properly for compact urban growth. (3)Under the ecological protection scenario, the area of high ecological security zones will be 39.39% larger than that under the business-as-usual scenario,and it tends to be distributed more evenly. The ecological security of the city clusters, including areas around Poyang Lake, the central part of Jiujiang, Xinyu and Ji'an, will be effectively protected. It is hoped that the present study can serve as a reference for the land use planning and ecological protection of thecity clusters around Poyang Lake.