摘要
不透水面比例是区域城镇化程度和生态环境变化的重要指示因子,分析不透水面比例时空格局分布可以揭示城市现在和未来的发展潜力,为城市环境保护和绿色可持续发展提供参考依据。以杭州市市辖区作为研究区,选取一期Sentinel-2B影像提取不透水面比例作为参考数据,基于4期Landsat影像利用随机森林算法反演获取1990—2017年间30 m空间分辨率杭州市不透水面比例数据集,精度验证结果表明,估算结果的平均绝对误差(mean absolute error,MAE)为6.3%~6.7%,均方根误差(root mean square error,RMSE)为13.4%~14.3%,表明反演模型具有较好的精度,能够准确反映不透水面的空间分布。结合不透水面加权中心、标准差椭圆和景观格局指数分析杭州市不透水面时空格局分布。结果表明:1990—2017年间,杭州市整体的不透水面比例呈增长趋势,2010—2017年间,年均不透水面比例增长最高,主要集中在余杭区和萧山区;由于杭州市发展的不平衡,在1990—2017年间,不透水面加权中心先后向北偏东—南—北方向移动;杭州市不透水面发展以西北—东南方向为主,聚集趋势较为稳定;景观格局变化显示各等级的不透水面景观均呈增长趋势且各等级不透水面景观分布渐趋均衡;自然地表、中密度和极高密度不透水面景观的团聚程度持续降低,破碎度越来越高,聚集度最高的是自然地表,且在研究时段内聚集度呈下降趋势。
The impervious surface percentage is an important indicator of regional urbanization and ecological environment changes.The spatial and temporal distribution of impervious surface percentage can reveal the current and future development potential of the city,and provide a reference for urban environmental protection and green sustainable development.In this paper,Hangzhou was selected as the study area,and one Sentinel-2B satellite image was used to extract the impervious surface percentage as reference data.Based on the four-phase Landsat satellite imagery,the authors used the random forest algorithm to invert the 30 m spatial resolution impervious surface percentage datasets from 1990 to 2017 in Hangzhou.The accuracy verification results show that the mean absolute error is from 6.3%to 6.7%,and the root mean square error is from 13.40%to 14.25%,indicating that the inversion model has great accuracy and can accurately reflect the spatial distribution of the impervious surface.Based on the impervious surface weighted mean center,standard deviation ellipse and landscape pattern index,the authors analyzed the spatial and temporal patterns of impervious surface in Hangzhou.The results are as follows:The impervious surface percentage in Hangzhou was increasing from 1990 to 2017,and the annual average growing of impervious surface percentage was the fastest from 2010 to 2017,mainly concentrated in Yuhang and Xiaoshan;Due to the unbalanced development of Hangzhou between 1990 and 2017,the impervious surface weighting mean centre moved to northeast at first,then moved to south,and finally moved to north;The northwest-southeast profile was the main direction of urban growth and the gathering trend was relatively stable in Hangzhou;The change of landscape pattern shows that the impervious landscapes of all types were increasing,and were distributed in a balanced trend;The natural surface,medium density and super high density impervious landscapes became less aggregated and increasingly fragmented;The aggregation of the impervious landscapes of all types was relatively stable,the highest degree of aggregation was the natural surface,and the lowest was the medium density impervious landscape.
作者
杨玉婷
陈海兰
左家旗
YANG Yuting;CHEN Hailan;ZUO Jiaqi(Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China;Bazhong Bureau of Natural Resources and Planning,Bazhong 636000, China)
出处
《国土资源遥感》
CSCD
北大核心
2020年第2期241-250,共10页
Remote Sensing for Land & Resources
