A consistent glacier inventory for Karakoram and Pamir derived from Landsat data: distribution of debris cover and mapping challenges
<p>Knowledge about the coverage and characteristics of glaciers in High Mountain Asia (HMA) is still incomplete and heterogeneous. However, several applications, such as modelling of past or future glacier development, run-off, or glacier volume, rely on the existence and accessibility of...
| Main Authors: | , , , , |
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| Language: | English |
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Copernicus Publications
2018-10-01
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| Series: | Earth System Science Data |
| Online Access: | https://www.earth-syst-sci-data.net/10/1807/2018/essd-10-1807-2018.pdf |
| _version_ | 1828491379572998144 |
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| author | N. Mölg T. Bolch P. Rastner T. Strozzi F. Paul |
| author_facet | N. Mölg T. Bolch P. Rastner T. Strozzi F. Paul |
| author_sort | N. Mölg |
| collection | DOAJ |
| description | <p>Knowledge about the coverage and characteristics of glaciers in High Mountain
Asia (HMA) is still incomplete and heterogeneous. However, several
applications, such as modelling of past or future glacier development,
run-off, or glacier volume, rely on the existence and accessibility of
complete datasets. In particular, precise outlines of glacier extent are
required to spatially constrain glacier-specific calculations such as length,
area, and volume changes or flow velocities. As a contribution to the
Randolph Glacier Inventory (RGI) and the Global Land Ice Measurements from
Space (GLIMS) glacier database, we have produced a homogeneous inventory of
the Pamir and the Karakoram mountain ranges using 28 Landsat TM and ETM+
scenes acquired around the year 2000. We applied a standardized method of
automated digital glacier mapping and manual correction using coherence
images from the Advanced Land Observing Satellite 1 (ALOS-1) Phased Array
type L-band Synthetic Aperture Radar 1 (PALSAR-1)
as an additional source of information; we then (i) separated the glacier
complexes into individual glaciers using drainage divides derived by
watershed analysis from the ASTER global digital elevation model version 2
(GDEM2) and (ii) separately delineated all debris-covered areas. Assessment
of uncertainties was performed for debris-covered and clean-ice glacier parts
using the buffer method and independent multiple digitizing of three glaciers
representing key challenges such as shadows and debris cover. Indeed, along
with seasonal snow at high elevations, shadow and debris cover represent the
largest uncertainties in our final dataset. In total, we mapped more than
27 800 glaciers > 0.02 km<sup>2</sup> covering an area of 35 520±1948 km<sup>2</sup> and an elevation range from 2260 to 8600 m. Regional median
glacier elevations vary from 4150 m (Pamir Alai) to almost
5400 m (Karakoram), which is largely due to differences in temperature and
precipitation. Supraglacial debris covers an area of 3587±662 km<sup>2</sup>,
i.e. 10 % of the total glacierized area. Larger glaciers have a higher
share in debris-covered area (up to > 20 %), making it an important
factor to be considered in subsequent applications
(<a href="https://doi.org/10.1594/PANGAEA.894707" target="_blank">https://doi.org/10.1594/PANGAEA.894707</a>).</p> |
| first_indexed | 2024-12-11T11:01:20Z |
| format | Article |
| id | doaj.art-ef18732ea2e741d9a71bc0a345677e77 |
| institution | Directory Open Access Journal |
| issn | 1866-3508 1866-3516 |
| language | English |
| last_indexed | 2024-12-11T11:01:20Z |
| publishDate | 2018-10-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Earth System Science Data |
| spelling | doaj.art-ef18732ea2e741d9a71bc0a345677e772022-12-22T01:09:53ZengCopernicus PublicationsEarth System Science Data1866-35081866-35162018-10-01101807182710.5194/essd-10-1807-2018A consistent glacier inventory for Karakoram and Pamir derived from Landsat data: distribution of debris cover and mapping challengesN. Mölg0T. Bolch1P. Rastner2T. Strozzi3F. Paul4Department of Geography, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland, SwitzerlandDepartment of Geography, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland, SwitzerlandDepartment of Geography, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland, SwitzerlandGamma Remote Sensing, Worbstr. 225, 3073 Gümligen, SwitzerlandDepartment of Geography, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland, Switzerland<p>Knowledge about the coverage and characteristics of glaciers in High Mountain Asia (HMA) is still incomplete and heterogeneous. However, several applications, such as modelling of past or future glacier development, run-off, or glacier volume, rely on the existence and accessibility of complete datasets. In particular, precise outlines of glacier extent are required to spatially constrain glacier-specific calculations such as length, area, and volume changes or flow velocities. As a contribution to the Randolph Glacier Inventory (RGI) and the Global Land Ice Measurements from Space (GLIMS) glacier database, we have produced a homogeneous inventory of the Pamir and the Karakoram mountain ranges using 28 Landsat TM and ETM+ scenes acquired around the year 2000. We applied a standardized method of automated digital glacier mapping and manual correction using coherence images from the Advanced Land Observing Satellite 1 (ALOS-1) Phased Array type L-band Synthetic Aperture Radar 1 (PALSAR-1) as an additional source of information; we then (i) separated the glacier complexes into individual glaciers using drainage divides derived by watershed analysis from the ASTER global digital elevation model version 2 (GDEM2) and (ii) separately delineated all debris-covered areas. Assessment of uncertainties was performed for debris-covered and clean-ice glacier parts using the buffer method and independent multiple digitizing of three glaciers representing key challenges such as shadows and debris cover. Indeed, along with seasonal snow at high elevations, shadow and debris cover represent the largest uncertainties in our final dataset. In total, we mapped more than 27 800 glaciers > 0.02 km<sup>2</sup> covering an area of 35 520±1948 km<sup>2</sup> and an elevation range from 2260 to 8600 m. Regional median glacier elevations vary from 4150 m (Pamir Alai) to almost 5400 m (Karakoram), which is largely due to differences in temperature and precipitation. Supraglacial debris covers an area of 3587±662 km<sup>2</sup>, i.e. 10 % of the total glacierized area. Larger glaciers have a higher share in debris-covered area (up to > 20 %), making it an important factor to be considered in subsequent applications (<a href="https://doi.org/10.1594/PANGAEA.894707" target="_blank">https://doi.org/10.1594/PANGAEA.894707</a>).</p>https://www.earth-syst-sci-data.net/10/1807/2018/essd-10-1807-2018.pdf |
| spellingShingle | N. Mölg T. Bolch P. Rastner T. Strozzi F. Paul A consistent glacier inventory for Karakoram and Pamir derived from Landsat data: distribution of debris cover and mapping challenges Earth System Science Data |
| title | A consistent glacier inventory for Karakoram and Pamir derived from Landsat data: distribution of debris cover and mapping challenges |
| title_full | A consistent glacier inventory for Karakoram and Pamir derived from Landsat data: distribution of debris cover and mapping challenges |
| title_fullStr | A consistent glacier inventory for Karakoram and Pamir derived from Landsat data: distribution of debris cover and mapping challenges |
| title_full_unstemmed | A consistent glacier inventory for Karakoram and Pamir derived from Landsat data: distribution of debris cover and mapping challenges |
| title_short | A consistent glacier inventory for Karakoram and Pamir derived from Landsat data: distribution of debris cover and mapping challenges |
| title_sort | consistent glacier inventory for karakoram and pamir derived from landsat data distribution of debris cover and mapping challenges |
| url | https://www.earth-syst-sci-data.net/10/1807/2018/essd-10-1807-2018.pdf |
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