Applicability of Landsat 8 data for characterizing glacier facies and supraglacial debris

• Published in: International journal of applied earth observation and geoinformation 2015-06, Vol.38, p.51-64
• Main Authors: Bhardwaj, Anshuman, Joshi, PK, Snehmani, Sam, Lydia, Singh, Mritunjay Kumar, Singh, Shaktiman, Kumar, Rajesh
• Format: Article
• Language: English
• Subjects: Glacier facies; Landsat 8; Remote sensing; Supraglacial debris
• ISSN: 1569-8432; 1872-826X; 1872-826X
• DOI: 10.1016/j.jag.2014.12.011

•Use of Landsat 8 OLI and TIRS bands for glacier facies and debris cover mapping.•A spectral profile based approach for increasing the efficiency of mapping.•Crevasses and slush zone on glacier also got mapped accurately.•A lapse rate based determination of transient freezing line was done.•OLI bands 1, 9, 5 and 6 along with TIRS band 10 were better to capture the facies. The present work evaluates the applicability of operational land imager (OLI) and thermal infrared sensor (TIRS) on-board Landsat 8 satellite. We demonstrate an algorithm for automated mapping of glacier facies and supraglacial debris using data collected in blue, near infrared (NIR), short wave infrared (SWIR) and thermal infrared (TIR) bands. The reflectance properties in visible and NIR regions of OLI for various glacier facies are in contrast with those in SWIR region. Based on the premise that different surface types (snow, ice and debris) of a glacier should show distinct thermal regimes, the ‘at-satellite brightness temperature’ obtained using TIRS was used as a base layer for developing the algorithm. This base layer was enhanced and modified using contrasting reflectance properties of OLI bands. In addition to facies and debris cover characterization, another interesting outcome of this algorithm was extraction of crevasses on the glacier surface which were distinctly visible in output and classified images. The validity of this algorithm was checked using field data along a transect of the glacier acquired during the satellite pass over the study area. With slight scene-dependent threshold adjustments, this work can be replicated for mapping glacier facies and supraglacial debris in any alpine valley glacier.