Simulating tidal and storm surge hydraulics with a simple 2D inertia based model, in the Humber Estuary, U.K

Abstract

a b s t r a c tThe hydraulic modelling of tidal estuarine environments has been largely limited to complex 3D models that are computationally expensive. This makes them unsuitable for applications which make use of live data to make real/near time forecasts, such as the modelling of storm surge propagation and associated flood inundation risks. To address this requirement for a computationally efficient method a reduced complexity, depth-integrated 2D storage cell model (Lisflood-FP) has been applied to the Humber Estuary, UK. The capability of Lisflood-FP to reproduce the tidal heights of the Humber Estuary has been shown by comparing modelled and observed tidal stage heights over a period of a week. The feasibility of using the Lisflood-FP model to forecast flood inundation risk from a storm surge is demonstrated by reproducing the major storm surge that struck the UK East Coast and Humber Estuary on 5 December 2013. Results show that even for this 2013 extreme event the model is capable of reproducing the hydraulics and tidal levels of the estuary. Using present day flood defences and observed flooding extents, the modelled flood inundation areas produced by the model were compared, showing agreement in most areas and illustrating the model's potential as a now-casting early warning system when driven by publically available data, and in near real-time. The Lisflood-FP model used was incorporated into the CAESAR-Lisflood GUI, with the calibration and verification of the estuarine hydraulics reported herein being a key step in creating an estuary evolution model, capable of operating in the decadal to century timescales that are presently underrepresented in estuarine predictive capability, and ultimately developing a model to predict the evolution of flood risk over the longer term.

Investigating compound flooding in an estuary using hydrodynamic modelling: a case study from the Shoalhaven River, Australia

“…The model performance was evaluated through the entire 7.25-day simulation period using the statistical measures R 2 and E RMS as presented by Skinner et al (2015). In addition, peak water level differences were calculated by subtraction of the observed peak water level from the modelled peak water level.…”

“…The dynamic modelling approach utilises a hydrodynamic model to simulate the flow of floodwater resulting from various sources such as storm tides and riverine discharges. These models have been applied successfully in coastal flood risk assessments at different scales and with varying degrees of model complexity (Bates et al, 2005;Gallien et al, 2011;Breilh et al, 2013;Maskell et al, 2013;Skinner et al, 2015;Seenath et al, 2016;Ramirez et al, 2016;Vousdoukas et al, 2016). A comprehensive overview of different flood inundation modelling methods as well as recent developments can be found in Teng et al (2017).…”

Response to Anonymous Referee #1

“…Zheng et al (2013) have found the strongest dependence between storm surge and extreme rainfall at the eastern Australian coastline for storm events with a duration of 2-4 days. The expansion of the modelling can be challenging, because the availability of suitable data for validating hydrodynamic modelling results is known to be limited for various reasons (Smith et al, 2012). To ensure that future storm events are recorded in a comprehensive manner, we recommend collecting observational data of storm events in an organised way, similarly to Haigh et al (2015).…”

“…The dynamic modelling approach utilises a hydrodynamic model to simulate the flow of floodwater resulting from various sources such as storm tides and riverine discharges. These models have been applied successfully in coastal flood risk assessments at different scales and with varying degrees of model complexity (Bates et al, 2005;Gallien et al, 2011;Breilh et al, 2013;Maskell et al, 2013;Skinner et al, 2015;Seenath et al, 2016;Ramirez et al, 2016;Vousdoukas et al, 2016). A comprehensive overview of different flood inundation modelling methods as well as recent developments can be found in Teng et al (2017).…”

Modelling inundation patterns and sediment dynamics in the extensive floodplain along the Tonle Sap River

“…The CL model was developed using a hydrological and hydraulic model (flow routing) based on TOPMODEL (Beven & Kirkby, ) and a model for erosion and deposition based on the Wilcock and Crowe () equation. It has been developed with a stage/tidal function to model the tidal environment and has been successfully applied in tidal environments (Ramirez, Lichter, Coulthard, & Skinner, ; Skinner et al, ). In the TSR, the water flow and inundation area are mainly controlled by the water level of the MR (Fujii et al, ); thus, the stage/tidal function is clearly applicable, also in the reverse flow environment of the TSR by simply incorporating water level/water stage.…”