The 2008 Morpeth Flood: Continuous Simulation Model for the Wansbeck Catchment (original) (raw)

2011, Newcastle university

The town of Morpeth, which lies in the Wansbeck catchment, experienced a catastrophic flood on the 6th September, 2008 which has resulted in this research. Occurrence of similar catastrophic floods around the world has increased the interest of the scientific community in using an alternative method i.e. continuous simulation to estimate flood risk. This method is completely different from current standard methodology [e.g. Flood Estimation Handbook (FEH)] in the UK for estimating flood risk. So, this study has examined the methodology used to develop a continuous simulation approach for the Wansbeck catchment and then made the model for upstream storage (near Mitford Hall and Font Ford Lodge) to reduce flood risk in the town of Morpeth. A previous study of the catchment has investigated the possibility of utilizing Lightwater storage to reduce flood risks to the town. The approach was to use data from 100 years of rainfall and to simulate the rainfall-runoff model to obtain the most significant flood. Then unsteady 1D hydraulic river model with and without Lightwater storage was modelled. Therefore, in this project, in order to show a fuller picture of a flood hydrograph, 24 ensemble rainfall model (during the event) with high resolution for every 5 minutes has been used to input rainfall- runoff and 1D river model during continuous simulation. During this project, an analysis of rainfall around the Wansbeck catchment has been made by using the 24 forecast ensemble rainfall model. Furthermore, a calibrated SHETRAN model has used the rainfall to simulate a rainfall-runoff model for every 15 minutes. The SHETRAN model was applied because it is a physically based, spatially- distributed modelling system for water flow, sediment and solute transport in the catchment. Hence the peak-flows hydrograph simulated by maximum, medium and minimum rainfall has been used as inputs for the NOAH 1D model with and without storage. Detailed results are shown during the project.