Paul is a hydrologist by background, but has widespread research interests in risk, resilience, uncertainty, governance and decision-making in relation to natural hazards and global water issues . He has published over 140 papers in international peer-reviewed journals, and these were cited over 700 times in 2013 according to the ISI Web of Knowledge. He currently has an ISI H-index of 37. For a full publication list see here.
Paul's main science contribution has been to improve the prediction of flood inundation through the development of new computer models, the use of data from new airborne, satellite and ground sensors and through the better characterization of risk and uncertainty. For a video of Paul talking about his research see here.
He has held Visiting Scientist positions at Princeton University, Dept. of Civil Engineering, Laboratoire National d'Hydraulique, Paris, the EU Joint Research Centre, Ispra, Italy and NASA Jet Propulsion Laboratory.
He also undertakes significant International collaboration, including work with the French National Space Agency (CNES), Instituto Nacional de Pesquisas da Amazônia in Brazil, as well as numerous universities in the US and Europe.
He is also on the working group of the Royal Society's working group looking at human resilience to climate change and disasters (http://royalsociety.org/policy/projects/resilience-climate-change).