Computer models of water flow (known as hydraulic models) help us understand where flooding is likely to happen and how bad that flooding might be. The SeriousGeoGames Lab has been involved in the use of hydraulic models to understand flood risk in estuaries – environments where rivers interact with the tides of the sea.
We tested the newly developed tidal input options in the CAESAR-Lisflood model to test the model’s ability to simulate tidal flows in the Humber Estuary, UK. The models was found to reproduce water levels across the estuary well, including for the extreme water levels and flooding caused by the the December 5th 2013 storm surge. This is the model used in our Humber in a Box activity.
Skinner, C.J., Coulthard, T.J., Parsons, D.R., Ramirez, J.A., Mullen, L. and Manson, S., 2015. Simulating tidal and storm surge hydraulics with a simple 2D inertia based model, in the Humber Estuary, UK. Estuarine, Coastal and Shelf Science, 155, pp.126-136. [Free version]
This method was further tested to assess flood risk in other areas, compared to results from using as simpler modelling method. It was found that using the CAESAR-Lisflood models simulated more accurate predictions of flooding.
Ramirez, J.A., Lichter, M., Coulthard, T.J. and Skinner, C., 2016. Hyper-resolution mapping of regional storm surge and tide flooding: comparison of static and dynamic models. Natural Hazards, 82(1), pp.571-590. [Free version]
In the Humber, the tides are dominant having a much greater role in the water levels than the rivers that drain into it. For smaller estuaries, this is not the case and rivers have a relatively larger influence on water levels. Floods in particular can impact water levels in estuaries and the level of detail used to represent the river flows changes the accuracy of the results.
Robins, P.E., Lewis, M.J., Freer, J., Cooper, D.M., Skinner, C.J. and Coulthard, T.J., 2018. Improving estuary models by reducing uncertainties associated with river flows. Estuarine, Coastal and Shelf Science, 207, pp.63-73. [Free version]