The biggest threat ever
The huge floods in Geelong in 1995 were caused by major flows in only a small area of the Barwons' huge catchment. But noone outside our territory , just as with the Gippsland floods over 10 years later seemed to know clearly what the return period really was .
On shore Easterlies were the key . They are rare down here but are still clearly influential in producing higher than ARR&R curve daily rainfall return estimates. We discovered that well before 1995, but it was news to many ( won't name them here ) who thought ARR&R design curve methods to be key to RP 's in design with flood water.
The floods currently affecting the east coast of Australia are being "talked up" almost every hour ( . "the biggest, the most unusual ever ". Careless talk needs to, like justice, be quickly killed if it is not to be come gospel. If agencies are still arguinng about answers, the public will be confused and easily led. What do you think is happening ? .
Localized geomorphic planning (based on soils shapes and substance on the ground ) provided us over 20 years ago with more reliability in rainfall estimates, runoff prediction and risk elements ( eg nature of bedload and debris) in a particular situation. The soil and slope elements alone require substantial integration beyond the arithmatic simplicities of water column measurements and estimates . We also found a way to explain why the BOM should not have dismissed the very high 24 hour totals recorded at both Benwerrin and Tanybyrn ( as they did) , using rainfall physics and orographic effects .
BOM rainfall estimates are not reliable simply because there are not enough of them where they are needed and the volunteers who man them are not always trusted ( you heard it first from EA)
The questions are
- Are agencies all across Australia still relying on an series of modelling curves and measurement scatter that doesn't take into account the specific geomorphic driver dimensions in a situation?
- Above aside , what are governmnets doing to ensure clarity of risk in any situation ? Clearly it is easier and tempting ( the way the press and polys treat a threat story ) for some to conclude that the Gippsland floods in 2007 and Toowoomba Ipswich flows in 2011 were thousand year floods( 1in 1000, 1in 5000 or 10000 etc ) when infact they should, like we do in the Otways, expect then much more often than that .The above flood in Geelong was caused by what we estimate was a 1:100 yr event or less . BW estimates over over 1in 1000 don't make sense in light of poor measurement records , inadequate researchthat considers actual catchment elements and their contribution.
- For insurance and drama and news purposes, is it easier to blame God rather than clear up our own areas of predjudice , ignorance and fear ? Are Governments and the media playing on fear ?
- At what cost do authorities dismiss realistic risk estimates?
- Why shouldn't people who choose to live / sell blocks in a high risk area pay extra or appropriate insurance?
- Why should we all pay for what appears to be a range of personal, local government and developer failures? ( the question of levies)
- As the Political Parties seem to be unified in support of levies,are we all then by implication to blame for a lack of real accountability ( in say planning ) here?
- Will insurance work for anyone in ten years if individual people are not held responsible for taking risky choices ?
- Is this casual acceptance of levies a powerful example of unsustainable approaches to risk management and insurance ? Governments who encourage risk takers instead of really warning them
- The BOM ( January 29th 2013)are currently asking for people to help collect climate data "to improve the climate record " Bit of a skew in the data? What value is "now and future data " when we aren't taking seriously the past and its history ( incl geomorphology) . Good to see that at last they are reviewing historical records more closely but is it a bit late to take the voluntary hours of thousands of Australians serioulsy?( esp friends who ONCE lived worked and recorded rain each day on the Otway and other ridges) Will BOM acknowledge that the data collection on climate has been poor and that a review of old data in the light of geomorphic and high implication error factors would be an important "now type" use of public money?
Labels: BOM records, correct return period advice, exaggeration of risk, flood levies, floods, incomplete assessment of risk, insurance, insurance advice, levees, levies, poor targeting of risk, unseen risks