Estimating River Surface Elevation From ArcticDEM. Issue 7 (6th April 2018)

• Record Type: Journal Article
• Authors: Dai, Chunli; Durand, Michael; Howat, Ian M.; Altenau, Elizabeth H.; Pavelsky, Tamlin M.
• Is Part Of: Geophysical research letters. Volume 45:Issue 7(2018)
• Page Start: 3107
• Page End: 3114
• Publication Date: 2018-04-06
• Subjects: river hydrology -- remote sensing -- satellite photogrammetry; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2018GL077379
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: ArcticDEM is a collection of 2‐m resolution, repeat digital surface models created from stereoscopic satellite imagery. To demonstrate the potential of ArcticDEM for measuring river stages and discharges, we estimate river surface heights along a reach of Tanana River near Fairbanks, Alaska, by the precise detection of river shorelines and mapping of shorelines to land surface elevation. The river height profiles over a 15‐km reach agree with in situ measurements to a standard deviation less than 30 cm. The time series of ArcticDEM‐derived river heights agree with the U.S. Geological Survey gage measurements with a standard deviation of 32 cm. Using the rating curve for that gage, we obtain discharges with a validation accuracy (root‐mean‐square error) of 234 m 3 /s (23% of the mean discharge). Our results demonstrate that ArcticDEM can accurately measure spatial and temporal variations of river surfaces, providing a new and powerful data set for hydrologic analysis. Plain Language Summary: Arctic rivers are poorly observed despite their potential sensitivity to climate change and importance to global hydrology. This is due to the sparsity of gages and lack of a reliable space‐based method for measuring river stage and discharge. Here we demonstrate that ArcticDEM, a collection of openly available repeat Digital Surface Models derived from submeter resolution satellite imagery, provides a powerful new data source for measuring river surface elevations and discharge from space. We apply these data near the Tanana River, Alaska, and compare ArcticDEM results to airborne and ground observations finding that ArcticDEM is able to detect short‐term variability in river height. Thus, ArcticDEM enables remote sensing measurements of currently unobserved rivers, improving our understanding of Arctic hydrology. Key Points: ArcticDEM provides a new data source for measuring river water surface elevations without the need for in situ data This paper presents an improved method of classifying water body through the combination of image entropy and brightness thresholding The precision of ArcticDEM water surface elevations is 32 cm over a 1‐km reach, and the accuracy of discharge is 234 m 3 /s