摘要
目前有关北京市不透水地表的相关研究多数是从整体层面开展,忽略了其内部功能区的作用及差异。运用分类回归树(CART)及系列变化检测模型得到北京市1991年、2001年、2011年和2015年四期不透水地表分布,并运用标准差椭圆、洛伦兹曲线、贡献指数及景观格局理论对各功能区不透水地表的时空变化进行分析。结果显示:1991-2015年北京市不透水地表的总面积增加了约144.18%,分布的主导方向由早期的东北—西南趋向于当前的正北—正南。各功能区间不透水地表的空间分布异质性逐渐减弱,但贡献指数值存在很大差异:功能拓展区的贡献指数最高,其四年中的最低值(1.79)高于其他功能区四年最高值,是北京市不透水地表增长最主要的贡献区;功能核心区的蔓延度指数值最高,约为其他功能区的2倍,为不透水地表的优势聚集区;发展新区的贡献值由负值变为正值并成倍增长,成为北京市不透水地表增长的主要源区;生态涵养发展区的贡献指数始终为负,并逐年减小。不同类型不透水地表的景观指数和质心偏移均存在差异,高盖度不透水地表的形状指数和斑块密度值最小,分布最为集中,对生态环境影响较大,北京市在未来发展过程中应合理规划控制其空间格局及增长模式,尽量减缓其增长速度及团聚程度。
IImpervious surface（IS） is often recognized as the indicator of regional ecosystems and environmental changes. Its spatio-temporal dynamics and ecological effects have been studied by many researchers, especially for the IS in Beijing municipality. However, most previous relevant studies examined Beijing as a whole without considering the differences and heterogeneity among the functional zones. In this study, the urban expansion in Beijing in some typical years（1991, 2001, 2005, 2011 and 2015） was analyzed by sub-pixel IS that obtained through the simulation of CART and change detection models. Then the spatio-temporal dynamics and variations of IS（1991, 2001, 2011 and 2015） in different functional zones and counties were analyzed based on the method of standard deviation ellipse, Lorenz curve,contribution index（CI） and landscape theory. It is found that the total area of impervious surface in Beijing increased dramatically from 1991 to 2015, increasing about 144.18%. The deflection angle of major axis of standard deviation ellipse decreased from 47.15° to 38.82°,indicating a trend that the major development axis in Beijing moved from the northeastsouthwest orientation to the north-south orientation. Moreover, the heterogeneity of IS distribution in different counties weakened gradually but the CI values and landscapes in different zones differed greatly. Urban function extended zone（UFEZ） had the highest CI value, which means it played the most important role in the growth of IS in Beijing, and its lowest CI value was 1.79 during the study period, which is much greater than the highest CI values of other functional zones. Core functional zone（CFZ） contributed less than UFEZ, but it has the highest CONTAG value, showing a more connected IS landscape compared with other zones. The CI values of new urban developed zone（NUDZ） increased rapidly from 1991 to2015, which increased from negative to positive and multiplied, indicating the NUDZ has become the main source for the growth of IS in Beijing gradually. However, the ecological conservation zone made a negative contribution at all times, and its CI value decreased constantly. In addition, the variations of landscape indices and centroids of impervious surface in different density classes indicate that the high-density impervious surface had a more compact configuration and a greater impact on the ecological environment.
出处
《地理学报》
EI
CSSCI
CSCD
北大核心
2017年第11期2018-2031,共14页
Acta Geographica Sinica
基金
国家重点基础研究发展计划(2015CB953603)
国家自然科学基金项目(41671339)
地表过程与资源生态国家重点实验室资助项目(2017-FX-01(1))~~
