Estimating design floods in a warming climate – gaps, challenges, and the way forward

A lot has been said and written about climate change and how it may make floods more frequent and extreme. In this 
talk I outline what needs to change in a warmer climate for design floods to change, present data based (as opposed 
to model based) evidence for all the changes till date, and present what I feel is the sensible way design flood 
estimation should be approached in this new climate we are in. Specifically, I show evidence for clear changes in 
the spatial and temporal patterns associated with extreme storms, along with an increase in design intensities for 
shorter duration events. These changes present the clearest evidence till date that design flood magnitudes for 
urban catchments across the world are increasing, a change that needs to be accepted and factored into our planning 
guidelines urgently given the implications this has to our existing stormwater infrastructure and society in general.

Some of the recent publications that will form the basis for much of this talk are:

Wasko, C. and A. Sharma (2015). "Steeper temporal distribution of rain intensity at higher temperatures within 
Australian storms." Nature Geoscience 8(7): 527-529.
Wasko, C., A. Sharma and F. Johnson (2015). "Does storm duration modulate the extreme precipitation-temperature 
scaling relationship?" Geophysical Research Letters 42(20): 8783-8790.
Wasko, C., A. Sharma and S. Westra ( 2016). "Reduced spatial extent of extreme storms at higher temperatures." 
Geophysical Research Letters 43: 4026–4032.
Woldemeskel, F. and A. Sharma (2016). "Should flood regimes change in a warming climate? The role of antecedent 
moisture conditions." Geophysical Research Letters 43.
              
More details about me are available at my LinkedIn page - https://au.linkedin.com/in/ashish-sharma-57711b55