Flood Forecasting
Itchen Catchment NFFS Configuration
Keywords: PDM Hydrologicat Analysis and Review, KW Hydrological Flood Routing, Flood Forecasting, ISIS Hydrodynamic Modelling, Tidal Modelling/Forecasting
Itchen Catchment Map.
Client, Architect & Other Organisations
EA Southern Region
Description - Itchen catchment Flood Forecasting Model
The Itchen catchment NFFS configuration involved the checking and assimilation of four types of flood forecasting module for the Itchen catchment which is highly permeable and thus well suited to continuous simulation modelling. Levels in the downstream reaches of the model are influenced by tidal effects and the model was configured to include astronomical tide levels as well as predicted surge from the CS3 model.
Description - Scope of Work
Edenvale Young (then Edenvale Modelling Services) were commissioned to incorporate the Itchen catchment into the Southern Region configuration of the Environment Agency's National Flood Forecasting System. The project included: The review and subsequent modification of the basic hydrological and hydraulic models supplied by Halcrow.
Four models were supplied which overlapped considerably and these were consolidated into two during the study. Analysis was undertaken of the ungauged catchment inflows and rating curves for gauged inflows. The modified hydrological and hydraulic models were then incorporated into the Southern Region NFFS configuration together with the Delft Hydraulics Error Correction Module implemented at each of the pre-defined forecasting points. NFFS Web Server reports were also configured as required.
Edenvale Young checked the calibration and the hydrological and hydraulic models were verified successfully using real data. The catchment models and configuration files were supplied to EA Southern Region and the catchment has been operational since May 2007.