Rapid evidence assessment of the use of emulators in flood risk analysis
This report assesses how emulators are used in flood risk activities
Documents
Summary
This report aims to provide a rapid evidence assessment of how emulators are used in flood risk activities. It reviews evidence of and different approaches to emulator use.
An emulator may be viewed as a “black box” - a system where the inputs and outputs are known, but where the inner workings of the model are simplified.
They are used extensively for flood risk modelling and analysis. For a selected set of input values, they provide an alternative approach to using many numerical models that require a lot of computational resource.
While emulators can be more resource efficient, they can produce errors. Therefore, they need more scrutiny and testing before they can be widely adopted within the Environment Agency and other Risk Management Authorities.
Findings
The main findings of our review indicate that:
- there are different ways of developing emulators dependent on the required predictive limits and data available
- emulators are currently used more widely within coastal modelling, than in hydrological or hydraulic modelling
- the use of emulators to consider the consequences of flooding has been limited, as these areas are already computationally efficient
- it is important to consider the accuracy and uncertainty of any emulator in the context of the overall analysis
- emulators have been used for flood risk analyses in combination with other approaches
Conclusions
The findings provide a guide for those unfamiliar with emulators and who would like to know more about their application and use. They also provide evidence of how and where emulators are used in wider industry. The report provides a useful starting point should the Environment Agency consider using emulators in future flood risk analyses.
Project Information
Project manager: Ian Perkins and others
This project was commissioned by the Environment Agency’s FCRM Directorate, as part of the joint Flood and Coastal Erosion Risk Management Research and Development Programme.