Mohamed Ismaiel Ahmed, Kevin Shook, Alain Pietroniro, Tricia Stadnyk, John W. Pomeroy (2022). Towards more effective representation of the variable contributing area in hydrologic models: 1. Model specific approach. Proceedings of the GWF Annual Open Science Meeting, May 16-18, 2022.

The northern prairie region of North America is known for its poorly defined drainage system, which is partly due to the existence of millions of surface depressions that intercept the lateral movement of surface runoff leading to variable contributing areas for streamflow generation and wetland recharge and substantial non-contributing areas. A few approaches have been attempted to represent these depressions to estimate the contributing area in hydrological models. However, these approaches are either simplistic and do not accurately represent the variable contributing area, or are very computationally demanding, which limits their general applicability. This is the first of a series of studies aiming to improve the representation of the variable contributing area in various hydrological and land surface models. In this study, a variable contributing area is implemented in the Hydrological Predictions for the Environment (HYPE) model. The internal lake module of HYPE has been replaced with the recently developed Hysteretic and Gatekeeping Depressional Model (HGDM) to estimate the variable contributing fractions of sub-basins. The modified model showed significant improvements in simulating streamflows from the agricultural and wetland dominated Smith Creek Research Basin in Saskatchewan, Canada. The model specific approach proposed here can be used with any model that has its own lake module. Efforts are being made to move towards more agnostic methods to implement HGDM in any hydrological model.

AOSM2022 Core modelling First Author: Mohamed Ismaiel Ahmed, Postdoctoral associate Additional Authors: Kevin Shook, Research Scientist; Alain Pietroniro, Professor and Schulich Chair in Sustainable Water Systems in a Changing Climate; Tricia Stadnyk, Associate Professor and Tier II CRC in Hydrologic Modelling; John W. Pomeroy, Distinguished Professor and Canada Research Chair in Water Resources and Climate Change;