Sensitivity of glacier volume change estimation to DEM void interpolation
<p>Glacier mass balance has been estimated on individual glacier and regional scales using repeat digital elevation models (DEMs). DEMs often have gaps in coverage (“voids”), the properties of which depend on the nature of the sensor used and the surface being measured. The way that these void...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-03-01
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| Series: | The Cryosphere |
| Online Access: | https://www.the-cryosphere.net/13/895/2019/tc-13-895-2019.pdf |
| Summary: | <p>Glacier mass balance has been estimated on individual glacier and regional
scales using repeat digital elevation models (DEMs). DEMs often have gaps in
coverage (“voids”), the properties of which depend on the nature of the
sensor used and the surface being measured. The way that these voids are
accounted for has a direct impact on the estimate of geodetic glacier mass
balance, though a systematic comparison of different proposed methods has
been heretofore lacking. In this study, we determine the impact and
sensitivity of void interpolation methods on estimates of volume change.
Using two spatially complete, high-resolution DEMs over southeast Alaska,
USA, we artificially generate voids in one of the DEMs using correlation
values derived from photogrammetric processing of Advanced Spaceborne Thermal
Emission and Reflection Radiometer (ASTER) scenes. We then compare 11
different void interpolation methods on a glacier-by-glacier and regional
basis. We find that a few methods introduce biases of up to 20 % in the
regional results, while other methods give results very close (<span class="inline-formula"><1</span> %
difference) to the true, non-voided volume change estimates. By comparing
results from a few of the best-performing methods, an estimate of the
uncertainty introduced by interpolating voids can be obtained. Finally, by
increasing the number of voids, we show that with these best-performing
methods, reliable estimates of glacier-wide volume change can be obtained,
even with sparse DEM coverage.</p> |
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| ISSN: | 1994-0416 1994-0424 |