This data set is aimed at the Daxueshan area in the middle part of Qilian Mountains. The data content includes the glacier surface elevation changes in the Daxueshan area during 1989-2000 and 2000-2014, including two data files, and the data format is GeoTIFF format. The data set contains two GeoTIFF files: the glacier surface elevation change from 1989 to 2000 and the glacier surface elevation change from 2000 to 2014. Each GeoTIFF file is a single band file, which contains the change of glacier surface elevation in Daxueshan area in the corresponding period. The spatial reference of data files is utm-47 / WGS-84 coordinate system, with spatial resolution of: elevationchange1989-2000.tif, spatial resolution: 25m; elevationchange2000-2014.tif, spatial resolution: 10M.
|collect time||1989/01/01 - 2014/12/31|
|collect place||Great Snow Mountain|
|data size||5.8 MB|
Data sources for 1989-2000: digital results of 1:50000 aerial topographic map of Daxueshan area in 1989 and SRTM data (resolution of 30m) in 2000. Data sources for 2000-2014: SRTM data in 2000 (resolution of 30m), and DEM generated by TanDEM-X / TerraSAR-X radar interferometry in 2014 (resolution of 10m).
Before the calculation of glacier surface elevation change, the multi-functional DEM corrector is used to repeatedly register and correct the DEM of the two periods involved in the calculation, so as to ensure that the two have the unified elevation datum and the lowest coordinate deviation, and then obtain the optimal glacier surface elevation change results. The resolution of the data set is selected according to the highest resolution of the DEM in the two periods involved in the difference. The difference between the lower resolution DEM and the higher resolution DEM is determined by bilinear interpolation method, and then the interpolation calculation is carried out to ensure that the difference results can reflect the changes of glacier surface elevation in two periods more precisely and accurately.
After checking the accuracy of DEM in different periods, the plane and elevation are corrected by using the cosine relationship between slope aspect and elevation difference. Then, the relationship between the maximum curvature and elevation difference is used to reduce the error caused by different resolutions. The DEM registration and relative accuracy evaluation of the two periods are carried out, and the glacier elevation changes in different periods are obtained
1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
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