基于主体功能区规划的中国城乡建设用地扩张时空特征遥感分析

21世纪以来,随着中国社会经济的快速发展,城乡建设用地不断扩张,对社会经济和生态环境造成了一系列影响.为了国家可持续发展目标的实现,必须对国土开发空间布局做出科学的规划.为此,一些学者开展了国家主体功能区规划方案研究,其研究成果支持了国家主体功能区规划的制定,该规划于2010年底颁布实施.为分析各类主体功能区在规划颁布前后城乡建设用地变化的特征,评估规划对区域开发的指导作用,及时发现规划实施中的问题,有必要采取有效手段对不同类型主体功能区的国土开发活动进行监测和评估.为此,本研究团队在已完成的2000年和2010年两期全国土地利用变化数据库的基础上,更新了2013年全国土地利用数据库,生成分期的城乡建设用地空间数据集;并对国家尺度各类主体功能区,以及东部,中部,西部,东北4大区域在主体功能区规划颁布前10年间(2000-2010年)和后3年内(2010-2013年)城乡建设用地扩张特征与差异进行了对比分析.结果表明:① 总体而言,2013年优化开发区,重点开发区,农产品主产区和重点生态功能区城乡建设用地在该类主体功能区国土面积中的占比明显不同,体现了国土开发按照不同主体功能布局的梯级特征.② 与2000-2010年相比,2010-2013年优化开发区城乡建设用地年增长率明显降低,重点开发区,农产品主产区和重点生态功能区建设用地年增长率均大幅增加;其中重点开发区和农产品主产区的城乡建设用地年均扩张面积已经超过了优化开发区;重点生态功能区城乡建设用地年均扩张面积和动态度仍处于最低的水平.③ 在区域尺度,优化开发区中,长江三角洲地区建设用地年均增量明显高于其他优化开发区;重点开发区中,西部地区在年增加面积和增加速率两方面均高于其他区域;农产品主产区中,东部,中部和西部地区内城乡建设用地年增加面积均超过前10年的2倍,西部地区的年增加速率更是达到前10年的3倍以上;重点生态功能区中,中部地区城乡建设用地的年变化率和动态度的增长均最为显著.④ 2010-2013年中国城乡建设用地扩张的空间格局和变化特征,在总体上体现了主体功能区规划的梯级开发特征.但是,局部优化开发区,农产品主产区和重点生态功能区建设用地的扩张速度过快,必须切实加强空间管控.研究表明,采用空间格局变化的分析方法,开展主体功能区规划颁布前后两个时期城乡建设用地扩张特征与分阶段区域差异的分析,清晰刻画出不同功能区和不同地区建设用地变化规律及其与主体功能区规划的契合程度,证明了该分析方法的有效性,可据此为未来国土开发空间格局的优化和城乡建设发展提供科学依据.

Remote Sensing-based Analysis of the Spatiotemporal Characteristics of Built-up area across China Based on the Plan for Major Function-oriented Zones

Since the beginning of the 21st century, built-up area had been increased driven by the rapid social and economic development, which had brought a series of socio-economic and environmental issues. In order to realize the goal of national sustainable development, China needs to scientifically formulate plans for developing and protecting land. Some scholars carried out the research on a draft plan for major function-oriented zones, which supportted the implementation of China's national plan for major function-oriented zones since 2010. In order to analyze the characteristics of built-up area in each major function-oriented zone before and after the plan's implement, as well as assess the plan's guiding role in regional development and possible problems in the plan's implementation promptly, it is necessary to adopt effective measures to monitor and evaluate land development activities in each of the major function-oriented zones. Therefore, using a China's Land Use Database (CLUD) during 2000-2010 interpreted from high-resolution remotely sensed images by our team, this study updated the CLUD between 2010 and 2013, and then developed the dataset of built-up area expansions for above two period. We analyzed and compared spatio-temporal characteristics and differences on built-up area expansion for national major function-oriented among China's four developing regions (east, central, west and northeast) in the periods for 2000-2010 and 2010-2013. The results showed the following: (1) On the whole, the percentage of built-up area in each of the major function-oriented zones was significant different, revealing the gradient feature of national land development based on the distribution of the main functions in 2013. (2) Compared to 2000-2010, in the period 2010-2013 annual growth rate in built-up area in optimal development zones decreased significantly, while annual growth rate in built-up area in key development zones, agricultural production zones and key ecological function zones increased significantly, with annual average expanding area of built-up area in key development zones and agricultural production zones exceeding that of optimal development zones, and the annual average expanding area and dynamic degree of built-up area remained lowest in key ecological function zones. (3) At the regional scale, the average annual increase in built-up area in optimal development zones in the Yangtze River Delta region was significantly higher than optimal development zones in other regions; the average area increase and rate of increase of built-up area in key development zones was faster in the western region than in other regions; average annual area growth of built-up area in agricultural production zones in the northeast, central and western regions was twice as high as the previous decade on average, while the annual rate of increase in the western region was three times as high as in the previous decade; the annual rate of change and increase in the dynamic degree of built-up area were most notable in key ecological function zones in the central region. (4) In general, the spatial pattern and characteristics of built-up area expansions in the period 2010-2013 reflected the gradient feature of the plan for major function-oriented zones. But the rate of increase locally in built-up aura in optimal development zones, agricultural production zones and key ecological function zones is fast, so the effective measures must be adopted in the implement of national and regional policies. By developing an analytical method to examine regional differences and spatial heterogeneity of built-up area expansions before and after the implement of the plan for major function-oriented zones, this study delineated the adjusting degree on between built-up area expansions from major function-oriented zones and the plan for major function-oriented zones. The conclusions indicated these methods and results were meaningful for future regulation strategies in optimizing national land development in China.