Cited by 156Hydrology and Sediment Transport ProcessesFlood Risk Assessment and ManagementRemote-Sensing Image Classification

The DOI matches its Crossref record; 28 of the 28 references it cites were found in a registry or an index; none of the 33 sources its claims cite is checked for support yet.

RivWidthCloud: An Automated Google Earth Engine Algorithm for River Width Extraction From Remotely Sensed Imagery

Open access
Yang, Xiao, Pavelsky, Tamlin M., Allen, George H., Donchyts, Gennadii·2020·IEEE Geoscience and Remote Sensing Letters

Abstract

The wetted width of a river is one of the most important hydraulic parameters that can be readily measured using remote sensing. Remotely sensed river widths are used to estimate key attributes of river systems, including changes in their surface area, channel storage, and discharge. Although several published algorithms automate river network and width extraction from remote sensing images, they are limited by only being able to run on local computers and do not automatically manage cloudy images as input. Here we present RivWidthCloud, a river width software package developed on the Google Earth Engine cloud computing platform. RivWidthCloud automatically extracts river centerline and widths from optical satellite images with the ability to flag observations that are obstructed by features like clouds, cloud shadows, and snow based on existing quality band classification. Because RivWidthCloud is built on a popular cloud computing platform, it allows users to easily apply the algorithm to the platform’s vast archive of remote sensing images, thereby reducing the users’ overhead for computing hardware and data storage. By comparing RivWidthCloud-derived widths from Landsat images to in situ widths from the U.S. and Canada, we show that RivWidthCloud can estimate widths with high accuracy (root mean square error: 99 m; mean absolute error: 43 m; mean bias: −21 m). By making RivWidthCloud publicly available, we anticipate that it will be used to address both river science questions and operational applications of water resource management.

Overview

AI snapshot

Written from the paper’s full text.

TL;DR

RivWidthCloud is a Google Earth Engine software package that automatically extracts river centerlines and widths from optical satellite imagery, including partially cloudy images, by adapting RivWidth and adding quality flags. Validation against same-day in situ widths from U.S. and Canada Landsat data shows high accuracy (RMSE 99.2 m; MAE 43.1 m; mean bias −20 m).

Key findings

  • RivWidthCloud extracts river centerlines and widths in three main steps: river mask, centerline, and width measurement; it uses GRWL to distinguish river pixels from nonriver water, checks connectivity to GRWL centerlines within a default 4-km radius, and removes islands smaller than a default ∼0.3 km².
  • It provides quality flags for cloud, cloud shadow, snow/ice, and topographic shadow; a nonzero flag suggests the width measurement may be impacted by that condition.
  • Validation used 1514 valid flag-free widths from Landsat images with same-day in situ measurements for 1984–2018, across the U.S. (492 stations with 1476 widths) and Canada (27 stations with 38 widths); RMSE was 99.2 m, MAE 43.1 m, and mean bias −20 m.
  • Unlike RivWidth, RivWidthCloud preserves each channel’s own centerline and measures each channel’s width separately rather than outputting a single centerline with total flow width summed across all channels.

Methods

  • Design: a Google Earth Engine implementation of RivWidth that works in principle with any remote sensing product providing water and obstruction classifications, but is described and validated using Landsat TM, ETM+, and OLI imagery.
  • River mask: spectral water classification with reported ∼97% accuracy using MNDWI, NDVI, and EVI thresholds; channel mask is all water pixels connected to GRWL river centerlines within a default 4-km radius; islands below ∼0.3 km² are removed.
  • Centerline and width: distance transform, gradient convolution, thresholding gradient values <0.9, and skeletonization produce a 1-pixel-wide centerline; spurious branches are trimmed by removing 500 pixels (∼1500 m for Landsat) or the segment length to the next confluence, whichever is shorter; widths are calculated along orthogonal directions using a 9 × 9-pixel kernel and w = w_m × u. Validation compares Landsat-derived widths to USGS and Water Survey of Canada same-day in situ widths.

Limitations

  • Stated: default centerlines do not guarantee connectivity at confluences; connectivity can be enforced by calculating the centerline from the river mask via skeletonization only, but this is slow and could exceed available GEE computational resources over large areas.
  • Stated: width accuracy depends on water classification and on cloud/shadow/snow/ice flagging accuracy; the error assessment is likely conservative because it does not account for in situ measurement errors or mismatches between in situ and satellite measurement locations where width changes rapidly.
  • Evident from the text: validation is limited to U.S. and Canada gauging stations and Landsat imagery, and RivWidthCloud is currently implemented only for Landsat products, though the authors state it can be expanded to other products such as Sentinel-2 or MODIS.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1109/lgrs.2019.2920225

Cites

28 of 28 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Verification

Claims the paper makes

22 Own interpretation · 15 Sources not found · 4 No basis given · 3 Own result

Show all 22 claims

  • It may state two separate claims as one. 13
  • Probably not a substantial claim. 10
22 of 22
  • The paper relies on this without support.

    Many satellite-based river discharge estimation methods that use river observations require river width as input.

    “Among various satellite-based river discharge estimation methods that use river observations, many require river width as input.”
  • The paper relies on this without support.

    Landsat has a long mission history.

    “Because of its accurate cloud classification algorithm [17] and its long mission history, we describe and validate RivWidthCloud using data from the Landsat program, specifically imagery from the Thematic Mapper (TM), Enhanced TM Plus, and Operational Land Imager instruments.”
  • The paper relies on this without support.

    The methods for classifying water and the accuracy of such classifications vary among remote sensing products.

    “The methods for classifying water and the accuracy of such classifications vary among remote sensing products.”
3 of 3

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

3 of 3

Citations

Cites

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Metadata

Authors
Yang, X., Pavelsky, T. M., Allen, G. H., & Donchyts, G.
Affiliations
  • University of North Carolina at Chapel Hill (US)
  • Texas A&M University (US)
  • Deltares (NL)
Venue
IEEE Geoscience and Remote Sensing Letters
Published
2020-02
Volume
17
Issue
2
Pages
217-221
ISSN
  • 1545-598X (ISSN-L)
  • 1558-0571
OpenAlex
W2955998290
Cited by
156
References
26
Citations by year
2026: 31 · 2025: 26 · 2024: 21 · 2023: 18 · 2022: 16 · 2021: 24 · 2020: 19
FWCI
10.62
Type
journal article
Language
en
Open access
Locations
  • IEEE Geoscience and Remote Sensing Letters (publishedVersion)
  • Carolina Digital Repository (University of North Carolina at Chapel Hill) (submittedVersion)
  • UNC Libraries
Funders
Jet Propulsion Laboratory
Topics
  • Physical Sciences › Earth and Planetary Sciences › Earth-Surface Processes › Hydrology and Sediment Transport Processes
  • Physical Sciences › Environmental Science › Global and Planetary Change › Flood Risk Assessment and Management
  • Physical Sciences › Computer Science › Computer Vision and Pattern Recognition › Remote-Sensing Image Classification
Keywords
cloud detection, cloud shadows, Landsat imagery, Google Earth Engine, cloud computing, automated image processing, water resources management

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