Implications of lateral groundwater flow across varying spatial resolutions in global land surface modeling
Akhter, T., Pokhrel, Y., Felfelani, F., Ducharne, A., Lo, M., et al. (2025). Implications of lateral groundwater flow across varying spatial resolutions in global land surface modeling. Water Resources Research, doi:https://doi.org/10.1029/2024WR038523
| Title | Implications of lateral groundwater flow across varying spatial resolutions in global land surface modeling |
|---|---|
| Genre | Article |
| Author(s) | T. Akhter, Y. Pokhrel, Farshid Felfelani, A. Ducharne, M. Lo, R. Reinecke |
| Abstract | Accurate groundwater representation in land surface models (LSMs) is vital for water and energy cycle studies, water resource assessments, and climate projections. Yet, many LSMs do not consider key processes including lateral groundwater flow and aquifer pumping, especially at the global scale. This study simulates these processes using an enhanced version of the Community Land Model (CLM5) and evaluates their roles at three spatial resolutions (0.5°, 0.25°, 0.1°). Results show that lateral flow strongly modulates water table depth and capillary rise at all resolutions. The magnitude of mean lateral flow increases from 25 mm/year at 0.5° to 36 mm/year at 0.25°, and 52 mm/year at 0.1° resolution, with pumping inducing lateral flow even at 0.5° (∼50 km), a typical grid size in global LSMs. Further, lateral flow alters runoff in regions with high recharge and shallow water table (e.g., eastern North America and Amazon basin), and soil moisture and ET in regions with comparatively low recharge and deeper water table (e.g., western North America, central Asia, and Australia) through enhanced capillary rise. Runoff alteration by lateral flow increases substantially with resolution, from a maximum of 15 mm/month at 0.5° to 20 mm/month and 25 mm/month at 0.25° and 0.1°, respectively; the impact of resolution on soil moisture and ET is less pronounced. While the model does not fully capture deeper water tables—warranting further enhancements—it provides valuable insights on how lateral groundwater flow impacts land surface processes, highlighting the importance of lateral groundwater flow and pumping in global LSMs. |
| Publication Title | Water Resources Research |
| Publication Date | Jul 1, 2025 |
| Publisher's Version of Record | https://doi.org/10.1029/2024WR038523 |
| OpenSky Citable URL | https://n2t.net/ark:/85065/d7fj2n7f |
| OpenSky Listing | View on OpenSky |
| RAL Affiliations | HAP |