Global River Topology (GRIT): A Bifurcating River Hydrography

Journal Article · Thu May 15 00:00:00 EDT 2025 · Water Resources Research

DOI:https://doi.org/10.1029/2024WR038308· OSTI ID:2570883

Wortmann, Michel ^[1]; Slater, Louise ^[2]; Hawker, L. ^[3]; Liu, Y. ^[2]; Neal, J. ^[3]; Zhang, B. ^[2]; Schwenk, Jonathan Paul ^[4]; Allen, George ^[5]; Ashworth, Phil ^[6]; Boothroyd, R. ^[7]; Cloke, H. ^[8]; Delorme, P. ^[9]; Gebrechorkos, S. H. ^[10]; Griffith, H. ^[11]; Leyland, J. ^[12]; McLelland, S. ^[13]; Nicholas, A. P. ^[14]; Sambrook‐Smith, G. ^[15]; Vahidi, E. ^[14]; Parsons, D. ^[16] ; Darby, S. E. ^[12]

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1. Univ. of Oxford (United Kingdom); European Centre for Medium‐Range Weather Forecasts (ECMWF), Reading (United Kingdom)
2. Univ. of Oxford (United Kingdom)
3. Univ. of Bristol (United Kingdom)
4. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
5. Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)
6. Univ. of Brighton, Sussex (United Kingdom)
7. Univ. of Liverpool (United Kingdom)
8. Univ. of Reading (United Kingdom)
9. École Normale Supérieure (ENS), Paris (France). Laboratoire de Géologie (LG); Paris Sciences et Lettres University (PSL) (France)
10. Univ. of Oxford (United Kingdom); Univ. of Southampton (United Kingdom)
11. JBA Consulting, Skipton (United Kingdom)
12. Univ. of Southampton (United Kingdom)
13. Univ. of Hull (United Kingdom)
14. Univ. of Exeter, Devon (United Kingdom)
15. Univ. of Birmingham (United Kingdom)
16. Loughborough Univ. (United Kingdom)

Existing global river networks underpin a wide range of hydrological applications but do not represent channels with divergent river flows (bifurcations, multi‐threaded channels, canals), as these features defy the convergent flow assumption that elevation‐derived networks (e.g., HydroSHEDS, MERIT Hydro) are based on. Yet, bifurcations are important features of the global river drainage system, especially on large floodplains and river deltas, and are also often found in densely populated regions. Here we developed the first raster and vector‐based Global RIver Topology that not only represents the tributaries of the global drainage network but also the distributaries, including multi‐threaded rivers, canals and deltas. We achieve this by merging a 30 m Landsat‐based river mask with elevation‐generated streams to ensure a homogeneous drainage density outside of the river mask for rivers narrower than approximately 30 m. Crucially, we employ the new 30 m digital terrain model, FABDEM, based on TanDEM‐X, which shows greater accuracy over the traditionally used SRTM derivatives. After vectorization and pruning, directionality is assigned by a series of elevation, flow angle and continuity approaches. The new global network and its attributes are validated using gauging stations, comparison with existing networks, and randomized manual checks. The new network represents 19.6 million km of streams and rivers with drainage areas greater than 50 km² and includes 67,495 bifurcations. With the advent of hyper‐resolution modeling and artificial intelligence, GRIT is expected to greatly improve the accuracy of many river‐based applications such as flood forecasting, water availability and quality simulations, or riverine habitat mapping.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: Natural Environment Research Council (NERC); USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 2570883
• Report Number(s): LA-UR--25-22772; 10.1029/2024WR038308; 1944-7973
• Journal Information: Water Resources Research, Journal Name: Water Resources Research Journal Issue: 5 Vol. 61; ISSN 1944-7973; ISSN 0043-1397
• Publisher: American Geophysical Union (AGU)
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES