THE 2053 SOUTH QUEENSLAND FLOOD

摘要

A ‘roadshow’ of flood engineers in the early 1980s‘prophesised’ the flooding that occurred in South EastQueensland (SE QLD) during 2011 to 2015. The eventsof 2011 to 2015 may have given increased credibilityto a long-held notion that SE QLD may be subject toa 40-year flood cycle. This paper examines the dataon flooding within the ten major SE QLD catchments,bounded by three mountain ranges and comprising morethan 63,000 km2. The purpose was to test the existenceand the strength of any regularity to flooding in this wellpopulatedregion of Australia. The approach identifiesthe flooding that occurred during predetermined fiveyearperiods that were 35 years apart – the 40-yearcycle – and the flooding that occurred outside of thesenominated 5 year periods. The basic statistics wereweighted for the length of flood record, catchment area,ranking of flood, and a combination of these factors. Theresults indicate that 69-87% of major floods in SE QLDhave occurred within a set of five year periods exactly35 years apart. No explanation is offered at this stage ofthe research. The implications for traditional hydrologicmethods are outlined.