The opposing factors controlling change in warming related future flood extremes

It is well accepted that warmer temperatures lead to greater moisture holding capacity for the atmosphere, resulting in bigger downpours, creating larger design precipitation intensities and possibly less secure flood infrastructure. It is also known that higher temperatures increase evaporation rates and hence dry soils quicker than before. This presentation discusses the role each of these controls plays in natural and urbanised catchments. It is shown that one of these two tends to dominate depending on a range of factors, including catchment attributes, as well as how extreme the design problem is. This presentation uses examples from four urban catchments spread across three continents as well as over 200 natural catchments representing various climatic zones in Australia to form its conclusions.