James, WHM and Carrivick, J (2016) Automated modelling of spatially-distributed glacier ice thickness and volume. Computers & Geosciences, 92. pp. 90-103. ISSN 0098-3004
Abstract
Ice thickness distribution and volume are both key parameters for glaciological and hydrological applications. This study presents VOLTA (Volume and Topography Automation), which is a Python script tool for ArcGISTM that requires just a digital elevation model (DEM) and glacier outline(s) to model distributed ice thickness, volume and bed topography. Ice thickness is initially estimated at points along an automatically generated centreline network based on the perfect-plasticity rheology assumption, taking into account a valley side drag component of the force balance equation. Distributed ice thickness is subsequently interpolated using a glaciologically correct algorithm. For five glaciers with independent field-measured bed topography, VOLTA modelled volumes were between 26.5% (underestimate) and 16.6% (overestimate) of that derived from field observations. Greatest differences were where an asymmetric valley cross section shape was present or where significant valley infill had occurred. Compared with other methods of modelling ice thickness and volume, key advantages of VOLTA are: a fully automated approach and a user friendly graphical user interface (GUI), GIS consistent geometry, fully automated centreline generation, inclusion of a side drag component in the force balance equation, estimation of glacier basal shear stress for each individual glacier, fully distributed ice thickness output and the ability to process multiple glaciers rapidly. VOLTA is capable of regional scale ice volume assessment, which is a key parameter for exploring glacier response to climate change. VOLTA also permits subtraction of modelled ice thickness from the input surface elevation to produce an ice-free DEM, which is a key input for reconstruction of former glaciers. VOLTA could assist with prediction of future glacier geometry changes and hence in projection of future meltwater fluxes.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016, Elsevier Ltd. This is an author produced version of a paper published in Computers & Geosciences. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Ice thickness distribution; Glacier volume; Subglacial topography; Glacier centrelines; Perfect-plasticity |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Geography (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 11 May 2016 09:30 |
Last Modified: | 18 Apr 2017 08:59 |
Published Version: | http://dx.doi.org/10.1016/j.cageo.2016.04.007 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.cageo.2016.04.007 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:99553 |