MESH - A Community Hydrology - Land Surface Model


In attendance at NHRC or by webex:

Chris Marsh, Dan Princz, Yonas Dibike, Fuad Yassin, Hammad Javid, Jeff Wong, Kurt Kornelsen, Moges Mamo, Luis Morales Marin, Paul Bartlett, Saman Razavi, Rajesh Shrestha, Chris Spence, Rehan Anis, Shervan Gharari, Matt Macdonald, Ala Bahrami, Mohamed Elshamy, Frezer Awol, Razi Sheikholeslami, Ric Soulis, Nic Wayand, Bruce Davison

Background:

This is part of an ongoing series of presentations organized to discuss progress in the collaborative large-scale modelling efforts between Environment and Climate Change Canada and the University of Saskatchewan. The presentations focus on individual large-scale modelling projects being undertaken by various members of the large-scale modelling community in Canada. The people who are invited to these meetings include representatives from Environment and Climate Change Canada, the University of Saskatchewan, and a few other individuals who have an interest in large-scale modelling activities in Canada.

Abstract: Modelling the hydrology and streamflow of the Mackenzie River Basin (MRB)

Accurate simulation of river streamflow is essential for water resources management and climate change impact studies. Hydrological models often route the streamflow using simple hydrological routing techniques that does not consider the characteristics of river channels or complex morphology present in certain rivers. Yet, for large river systems, as well as for regional and global modelling, routing effects can have a very significant impact on the magnitude of flood peaks and the timing of flows to seas and oceans. In this study, an approach to couple the MESH (Modélisation Environmentale Communautaire-Surface and Hydrology) model, which embeds the Canadian land surface scheme (CLASS), with a one-dimensional river hydraulic model (River-1D) of the main Mackenzie river and the 3 of its main tributaries (Peace, Athabasca, and Slave) is reported.  Inflows at designated locations on those rivers are generated by the MESH hydrologic model run at 0.125° spatial resolution and 30 minutes temporal resolution. The MESH model of the MRB has been calibrated for parts of the basin and a number of the existing lakes have been incorporated in the model to improve the simulations of streamflow. The one-dimensional hydraulic model simulates the routing along the river in a one-way coupling mode with due consideration to river ice processes including freeze-up and break-up. This approach improves the accuracy of river flow simulations along the main stem of the Mackenzie and its main tributaries and allows for studying sediment transport and dynamic events, such as dam breaches or ice jam release and formation events.

Introduction:

Bruce Davison welcomed everyone to the meeting and said a few words to set the stage for Mohamed Elshamy's presentation.

Summary:

Mohamed gave his presentation on hydrological modelling of the Mackenzie River Basin with MESH. Mohamed’s presentation can be found here

The webex of the meeting can be found here: https://pwgsc-nh.webex.com/pwgsc-nh/ldr.php?RCID=8669a32df721a635790cd1bbd4b1f8f1

At the end of the presentation, Al Pietroniro congratulated Mohamed on his work and highlighted that Mohamed has made a lot of progress. Al noted that the difference in streamflow volume between MESH and MESH + MRBHM was strange and needed further investigation. He also noted Mohamed's work to use MESH's default stage-discharge relationship for lakes and suggested that a paper could focus on this aspect of the work, indicating that stage-discharge relationships for lakes just don't work.

Saman asked about the ice jam capabilities of MESH. Mohamed responded that MESH does not deal with ice jams, but the MRBHM might. Hammad indicated that he would be working to bring the RIVICE-1D model into MESH and that Prabin has already begun linking the models. Al suggested that a good first step would be to try to form ice first, then see if the model can even replicate ice thickness throughout the ice-up season into the recession period.

Yonas asked why Mohamed had only focused on streamflow instead of including other aspects like SWE, evaporation or other state variables. Mohamed responded by saying that this was a good point that would be part of future work. Al also responded saying that comparing to other parts of the water budget is part of the overall strategy and that Mohamed's work was a good step in the right direction. He also highlighted the general lack of data regarding other aspects of the water cycle. Al also talked about the need to look at scaling... in other words, can we upscale from the WECC observatories to the basin-scale. Al also talked about the need to deal with fill-and-spill processes in the eastern part of the MRB. Mohamed pointed out that Ala is also looking at GRACE and SWE on the Liard.

Ric Soulis, who led some of the pioneering work with MESH (WATCLASS) on the Mackenzie, congratulated Mohamed on his work and highlighted the iterative process that has taken place over the decades. Ric indicated that the next step was to look again at the physical processes, as they are represented in the model, to identify weaknesses.

The meeting was concluded.

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