星载激光测高结合遥感影像的青海湖变化监测

Monitoring of Qinghai Lake changes with spaceborne laser altimetry and remote sensing images

为了准确反映全球气候的不断变化给湖泊湿地生态系统带来长时间水位、面积和蓄水量变化,针对星载激光测高数据筛选条件不足引起湖泊水位不准确的问题,提出了基于IQR湖陆分界多准则约束的激光点筛选方法。以青海湖为研究对象,利用ICESat/GLAS激光测高数据和30 m分辨率的Landsat遥感影像数据,研究分析青海湖2003到2009年间的湖泊水位、面积和蓄水量变化。结果表明:青海湖的年均水位、面积和蓄水量分别以0.096 m/a、12.915 km^2/a和0.088 km^3/a在升高,其中水位年均变化率相对误差仅为4.95%;2009年和2003年相比,湖泊水位增加了0.437 m,面积增加了74.128 km^2,相应的蓄水量增加了2.81 km^3,并与水位站实测结果基本一致。该方法有效实现了粗差探测识别问题,避免了粗差对高程序列的影响,对后续国产激光卫星在湖泊中的应用具有参考价值。

In order to accurately reflect the global climate changes to the lake wetland ecosystem brought long-term water level,area and water storage changes,Aiming at the problem of inaccurate lake water level caused by insufficient screening conditions of spaceborne laser altimetry data. In this paper,a laser point selection method based on IQR multi-criteria constraint is proposed. Taking Qinghai Lake as the research object,using ICESat/GLAS laser altimetry data and Landsat satellite image data with 30 m resolution,the changes of water level,area and water storage of Qinghai lake from 2003 to 2009 are studied and analyzed. The results show that the annual average water level,area and water storage of Qinghai Lake amount are increasing at 0.096 m/a,12.915 km^2/a and 0.088 km^3/a,respectively. The relative error of the average annual change rate of the water level was only 4.95%. Compared 2009 with 2003,the lake water level increased by 0.437 m,the area increased by 74.128 km^2,and the corresponding water storage increased by 2.81 km^3,which was basically consistent with the field observation results of the water level station. The method effectively realizes the problem of error detection and identification,avoids the influence of gross error on high program ranks,and has reference value for the application of subsequent domestic laser satellites in lakes.