Technical Note: Semi-automated effective width extraction from time-lapse RGB imagery of a remote, braided Greenlandic river
River systems in remote environments are often challenging to monitor and understand where traditional gauging apparatus are difficult to install or where safety concerns prohibit field measurements. In such cases, remote sensing, especially terrestrial time-lapse imaging platforms, offer a means to...
Published in: | Hydrology and Earth System Sciences |
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Online Access: | https://doi.org/10.5194/hess-19-2963-2015 https://noa.gwlb.de/receive/cop_mods_00016046 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00016001/hess-19-2963-2015.pdf https://hess.copernicus.org/articles/19/2963/2015/hess-19-2963-2015.pdf |
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00016046 2023-05-15T15:12:13+02:00 Technical Note: Semi-automated effective width extraction from time-lapse RGB imagery of a remote, braided Greenlandic river Gleason, C. J. Smith, L. C. Finnegan, D. C. LeWinter, A. L. Pitcher, L. H Chu, V. W. 2015-06 electronic https://doi.org/10.5194/hess-19-2963-2015 https://noa.gwlb.de/receive/cop_mods_00016046 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00016001/hess-19-2963-2015.pdf https://hess.copernicus.org/articles/19/2963/2015/hess-19-2963-2015.pdf eng eng Copernicus Publications Hydrology and Earth System Sciences -- http://www.bibliothek.uni-regensburg.de/ezeit/?2100610 -- http://www.hydrol-earth-syst-sci.net/volumes_and_issues.html -- 1607-7938 https://doi.org/10.5194/hess-19-2963-2015 https://noa.gwlb.de/receive/cop_mods_00016046 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00016001/hess-19-2963-2015.pdf https://hess.copernicus.org/articles/19/2963/2015/hess-19-2963-2015.pdf uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2015 ftnonlinearchiv https://doi.org/10.5194/hess-19-2963-2015 2022-02-08T22:54:20Z River systems in remote environments are often challenging to monitor and understand where traditional gauging apparatus are difficult to install or where safety concerns prohibit field measurements. In such cases, remote sensing, especially terrestrial time-lapse imaging platforms, offer a means to better understand these fluvial systems. One such environment is found at the proglacial Isortoq River in southwestern Greenland, a river with a constantly shifting floodplain and remote Arctic location that make gauging and in situ measurements all but impossible. In order to derive relevant hydraulic parameters for this river, two true color (RGB) cameras were installed in July 2011, and these cameras collected over 10 000 half hourly time-lapse images of the river by September of 2012. Existing approaches for extracting hydraulic parameters from RGB imagery require manual or supervised classification of images into water and non-water areas, a task that was impractical for the volume of data in this study. As such, automated image filters were developed that removed images with environmental obstacles (e.g., shadows, sun glint, snow) from the processing stream. Further image filtering was accomplished via a novel automated histogram similarity filtering process. This similarity filtering allowed successful (mean accuracy 79.6 %) supervised classification of filtered images from training data collected from just 10 % of those images. Effective width, a hydraulic parameter highly correlated with discharge in braided rivers, was extracted from these classified images, producing a hydrograph proxy for the Isortoq River between 2011 and 2012. This hydrograph proxy shows agreement with historic flooding observed in other parts of Greenland in July 2012 and offers promise that the imaging platform and processing methodology presented here will be useful for future monitoring studies of remote rivers. Article in Journal/Newspaper Arctic Greenland greenlandic Isortoq Niedersächsisches Online-Archiv NOA Arctic Greenland Isortoq River ENVELOPE(-76.998,-76.998,69.968,69.968) Hydrology and Earth System Sciences 19 6 2963 2969 |
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article Verlagsveröffentlichung Gleason, C. J. Smith, L. C. Finnegan, D. C. LeWinter, A. L. Pitcher, L. H Chu, V. W. Technical Note: Semi-automated effective width extraction from time-lapse RGB imagery of a remote, braided Greenlandic river |
topic_facet |
article Verlagsveröffentlichung |
description |
River systems in remote environments are often challenging to monitor and understand where traditional gauging apparatus are difficult to install or where safety concerns prohibit field measurements. In such cases, remote sensing, especially terrestrial time-lapse imaging platforms, offer a means to better understand these fluvial systems. One such environment is found at the proglacial Isortoq River in southwestern Greenland, a river with a constantly shifting floodplain and remote Arctic location that make gauging and in situ measurements all but impossible. In order to derive relevant hydraulic parameters for this river, two true color (RGB) cameras were installed in July 2011, and these cameras collected over 10 000 half hourly time-lapse images of the river by September of 2012. Existing approaches for extracting hydraulic parameters from RGB imagery require manual or supervised classification of images into water and non-water areas, a task that was impractical for the volume of data in this study. As such, automated image filters were developed that removed images with environmental obstacles (e.g., shadows, sun glint, snow) from the processing stream. Further image filtering was accomplished via a novel automated histogram similarity filtering process. This similarity filtering allowed successful (mean accuracy 79.6 %) supervised classification of filtered images from training data collected from just 10 % of those images. Effective width, a hydraulic parameter highly correlated with discharge in braided rivers, was extracted from these classified images, producing a hydrograph proxy for the Isortoq River between 2011 and 2012. This hydrograph proxy shows agreement with historic flooding observed in other parts of Greenland in July 2012 and offers promise that the imaging platform and processing methodology presented here will be useful for future monitoring studies of remote rivers. |
format |
Article in Journal/Newspaper |
author |
Gleason, C. J. Smith, L. C. Finnegan, D. C. LeWinter, A. L. Pitcher, L. H Chu, V. W. |
author_facet |
Gleason, C. J. Smith, L. C. Finnegan, D. C. LeWinter, A. L. Pitcher, L. H Chu, V. W. |
author_sort |
Gleason, C. J. |
title |
Technical Note: Semi-automated effective width extraction from time-lapse RGB imagery of a remote, braided Greenlandic river |
title_short |
Technical Note: Semi-automated effective width extraction from time-lapse RGB imagery of a remote, braided Greenlandic river |
title_full |
Technical Note: Semi-automated effective width extraction from time-lapse RGB imagery of a remote, braided Greenlandic river |
title_fullStr |
Technical Note: Semi-automated effective width extraction from time-lapse RGB imagery of a remote, braided Greenlandic river |
title_full_unstemmed |
Technical Note: Semi-automated effective width extraction from time-lapse RGB imagery of a remote, braided Greenlandic river |
title_sort |
technical note: semi-automated effective width extraction from time-lapse rgb imagery of a remote, braided greenlandic river |
publisher |
Copernicus Publications |
publishDate |
2015 |
url |
https://doi.org/10.5194/hess-19-2963-2015 https://noa.gwlb.de/receive/cop_mods_00016046 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00016001/hess-19-2963-2015.pdf https://hess.copernicus.org/articles/19/2963/2015/hess-19-2963-2015.pdf |
long_lat |
ENVELOPE(-76.998,-76.998,69.968,69.968) |
geographic |
Arctic Greenland Isortoq River |
geographic_facet |
Arctic Greenland Isortoq River |
genre |
Arctic Greenland greenlandic Isortoq |
genre_facet |
Arctic Greenland greenlandic Isortoq |
op_relation |
Hydrology and Earth System Sciences -- http://www.bibliothek.uni-regensburg.de/ezeit/?2100610 -- http://www.hydrol-earth-syst-sci.net/volumes_and_issues.html -- 1607-7938 https://doi.org/10.5194/hess-19-2963-2015 https://noa.gwlb.de/receive/cop_mods_00016046 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00016001/hess-19-2963-2015.pdf https://hess.copernicus.org/articles/19/2963/2015/hess-19-2963-2015.pdf |
op_rights |
uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/hess-19-2963-2015 |
container_title |
Hydrology and Earth System Sciences |
container_volume |
19 |
container_issue |
6 |
container_start_page |
2963 |
op_container_end_page |
2969 |
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1766342933933457408 |