The preliminary flood risk assessments will be used to identify areas which need to be considered in more detail through mapping and potentially the preparation of flood risk management plans. In order to assess flood risk it is necessary to identify both the probability and consequences of flooding.
Much of the research in Theme 1 of FLOODsite is relevant in the assessment of flood risk. In terms of assessing the probability of the flood hazard, the outputs of Task 2 provide up-to-date statistical tools for looking at the probability of extreme events both at a point and the variation spatially.
Where raised defences are used as flood mitigation measures in an area, it is important to recognise in quantifying the risk of flooding that all engineered structures will have a finite probability of failure at less than the design loading but also may have a performance which exceeds the design standard. Thus Task 4, Task 6 and Task 7 provide underpinning knowledge and methods to examine the reliability of existing flood defences that can form part of a flood risk assessment.
However, the existence of raised defences may be taken as an indication that risk maps and plans need to be prepared. In that case the contribution of the science in Task 4, Task 6 and Task 7 will be directly in these subsequent activities. Likewise it is not yet clear whether the flood damage estimation guidelines developed in Task 9 or the estimation of loss-of-life developed in Task 10 will be needed in preliminary assessments. If the preliminary flood risk assessment involves initial drafting of flood inundation and consequence maps, then other FLOODsite results are also relevant, see the page on the preparation of Flood Risk Maps.