1. Current needs

3. End Users • Owners and Managers of “wet infrastructure” • Flood protection dykes and levees • Usually some level of Government • With reactive intervention by higher levels of Government after a failure • Most significant dams are in “public ownership” • Relatively small number of dams in private ownership • Public • Want to be assured of their safety in the vicinity of the structure • Public policy makers • Politicians want the same assurances as the Public

4. The form of the problem of interest Simulation of Tous Dam Failure Type Scenario

5. Can the problem be solved by science?

6. To manage catastrophic flood risks

7. Basis for international co-operation…. • Problem often has international dimensions • Physical effects can cross national boundaries • Effects in one country have “knock-on” effects in other distant countries • Physics of phenomena independent of culture and politics • Possibly local variations of general problem of physics • Problems of concern too large for individual dam owner or authority responsible for integrity of flood protection structures

8. Scientific needs • For general political and societal acceptance • Confirmatory research • Independently reproducible: necessary condition • Creation of a sufficiently large body of supporting evidence • Independent review by those who are sceptical • Contradictory research • Independently challenged: necessary condition • Demonstration that a sufficiently large search for errors and weaknesses has been carried out • Independent review by those who are not sceptical • Broadly based peer review and acceptance • By the wider scientific community: necessary condition

9. Simplification • Need to be clear what is being simplified: • Are we simplifying • “the problem”, or, • “the way of solving” the problem • Uncertainty is a complex phenomenon • There is a need to distinguish between

10. Some sobering thoughts….. • Many of the phenomena involved fall into the domain of “trans-science” • “Trans-science”: there are questions that can be asked of science, but cannot yet be answered by science • Research necessarily dominated by “uncertainty” • Making it necessary to work in the domain of probability • Probabilistic reasoning is difficult, • Probabilistic reasoning is not intuitive. • Which means that there is no “simple and practical” way to properly formulate a scientific solution!