Relative importance of hydrological uncertainities

The Flood Hydrology Improvements Programme secured a Strategic Outline Case approval from LPRG in April 2021. We are now progressing the development of a number of Review/Initial Assessment type projects to highlight the scale of operational hydrology challenges and the require improvements for the Environment Agency. The Relative Uncertainty in the Modelling Chain project is one of the key subject areas required to assist in the compilation of our Full Business Case. This project will be delivered in three work packages.

Work Package 1 - Carry out a literature review of recent scientific research and current best practice to identify the different sources of uncertainty that are evident throughout the whole flood modelling chain (i.e. from input data to decision). Evidence should be gathered to indicate the potential scale of the different uncertainties and how and why this can vary.

Work Package 2 - Use a series of high profile case studies to illustrate the significance of hydrological uncertainty within the flood modelling chain and how this varies depending on the catchment type, flood source and/ or modelling approach.

Work Package 3 - Summarise the findings and identify the key sources of uncertainty which can affect the accuracy of the final flood estimate (in terms of peak flow, volume and timing) and in turn influence the final decision making. Recommendations will be made as to where we should focus our efforts to minimise the hydrological uncertainty in the future.