Publication Details |
| Category | Text Publication |
| Reference Category | Journals |
| DOI | 10.1029/2024WR038183 |
Licence  |
|
| Title (Primary) | A novel stream network upscaling scheme for accurate local streamflow simulations in gridded global hydrological models |
| Author | Shrestha, P.K.; Samaniego, L.
; Rakovec, O.
; Kumar, R.
; Thober, S.
|
| Source Titel | Water Resources Research |
| Year | 2025 |
| Department | CHS |
| Volume | 61 |
| Issue | 6 |
| Page From | e2024WR038183 |
| Language | englisch |
| Topic | T5 Future Landscapes |
| Data and Software links | https://doi.org/10.5281/zenodo.6840021 |
| Keywords | global streamflow; SCC; catchment conservation; scalability; D8; mHM |
| Abstract | Large-scale hydrological models are progressing toward sub-kilometer resolutions to achieve “locally relevant hydrological simulations.” However, grid-based domain representations introduce significant errors in streamflow within small catchments, a challenge that remains unresolved by state-of-the-art modeling schemes, such as 8-directional gridded routing (D8). Here, we introduce the Subgrid Catchment Conservation (SCC) scheme to enhance streamflow estimation at any location within the domain using a coarse resolution (i.e., 1 km or more), continental scale, grid-based hydrological model (HM). Gridded HMs not preserving the DEM-reference (or subgrid) catchment area is usually referred as the catchment size problem. SCC allows multiple outflow from grid cells, a key feature that preserves the subgrid catchment area of all points of interest across scales. SCC is a general concept; however, for demonstration purposes, it has been implemented in the mesoscale hydrological model, mHM. We employ a global setup with 62 large-scale domains encompassing 5,256 streamflow gauging stations, and a regional setup encompassing 187 stations in the Rhine river basin. We found that the widely used D8 scheme's efficacy diminishes drastically for catchments under 30 times the grid size. SCC demonstrates remarkable consistency in streamflow in the regional experiment with nine out of 10 stations exceeding the mean flow benchmark (KGE −0.41) across 1–100 km model resolutions. In addition, SCC's ability to resolve multiple points of interests in a grid leads to greater modeling flexibility. By addressing the catchment size problem, SCC marks a significant advancement for global-scale simulations producing locally relevant streamflow. |
| Persistent UFZ Identifier | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=30833 |
| Shrestha, P.K., Samaniego, L., Rakovec, O., Kumar, R., Thober, S. (2025): A novel stream network upscaling scheme for accurate local streamflow simulations in gridded global hydrological models Water Resour. Res. 61 (6), e2024WR038183 10.1029/2024WR038183 |
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