Influence of changes in rainfall and soil moisture on trends in flooding
C Wasko, R Nathan
Journal of Hydrology | Elsevier | Published : 2019
© 2019 Elsevier B.V. Despite the expectation that increases in rainfall with climatic change will result in increases in pluvial flooding, there is more historical evidence for decreases in flood magnitude. In Australia, as in many other parts of the world, flood magnitudes are mostly decreasing, despite increasing rainfall extremes. Here, we show how changes in soil moisture have led to decreasing flood magnitudes while rainfall extremes have been increasing. Using gauged streamflow, catchment average rainfall, and modelled soil moisture data across Australia we confirm that streamflow peaks (or floods) that occur at least once a year are strongly related to both the peak rainfall causing t..View full abstract
The HRS streamflow data set is publicly available from www.bom.gov.au/hrs. Gridded rainfall from AWAP is freely available from http://www.csiro.au/awap/and gridded AWRA-L soil moisture is freely available upon request from http://www.bom.gov.au/water/landscape/. The authors thank Keirnan Fowler for provision of catchment boundaries, Tim Peterson for rainfall extraction code, Andrew Frost for code to extract soil moisture data from AWRA-L, and Murray Peel and Andrew Western for analysis suggestions. Conrad Wasko acknowledges support from the University of Melbourne McKenzie Postdoctoral Fellowship scheme.