夜光遥感数据的西部地区城市扩展时空变化

Temporal and spatial changes of urban expansion in western China based on night-light remote sensing data

针对我国西部地区12个省(自治区、直辖市)的城市扩展时空变化规律,该文采用1992—2019年的DMSP-OLS与NPP-VIIRS两种夜光遥感数据形成夜间灯光数据集,对研究区主要以城市面积叠加、扩展强度、扩展速度、标准差椭圆等方法进行分析。结果显示:西部地区城市面积保持持续增长,城市新增区域颇为明显。西部地区城市扩展强度普遍递增,但各地区递增幅度差距较大。西部地区城市面积扩展速度普遍上升,各地区扩展速度的增长幅度有较大的差别;在研究期末段,部分地区扩展速度上升幅度明显降低。西南地区与西北地区标准差椭圆相差较大,西北地区椭圆长短轴长度差别较大;西南地区标准差椭圆长短轴长度差别较小,椭圆形状更接近圆形。

Aiming at the spatio-temporal change rule of urban expansion of 12 provinces(autonomous regions and municipalities)in western China.urban area superposition,expansion intensity,expansion speed,standard deviation ellipse and other methods were used for analysis in this paper by the night-light data set formed by DMSP-OLS and NPP-VIIRS night-light remote sensing data from 1992 to 2019.The results showed that the urban area of the western region maintained a continuous growth,and the new urban area was quite obvious.The urban expansion intensity in the western region has generally increased,but there was a large gap in the increase rate among different regions.The urban area expansion rate in the western region generally increased,and the growth rate of the expansion rate of each area was different;at the end of the research period,the rate of increase of the expansion rate in some areas decreased significantly.The standard deviation ellipse of the southwest region and the northwest region were quite different;the standard deviation of the ellipse in the southwest region was long,the difference in the length of the short axis was small,and the shape of the ellipse was closer to a circle.