Overdue that I updated the chart for my Perth dams catchment May-Oct rain index
July 2021 was a big month for Perth dam catchments rain and I blogged –
Bickley in Perth Hills wettest year since 1996
Overdue that I updated the chart for my Perth dams catchment May-Oct rain index
July 2021 was a big month for Perth dam catchments rain and I blogged –
Bickley in Perth Hills wettest year since 1996
My screen shows the bars for 2020 & 2021 cut off – so –
To see the chart fully – try this link – you may have to download it – it was posted as a jpg file.
Ever since I updated the wordpress version editing text – adding links – adding images – whatever – is a timewasting pain in the butt –
Does this mean that Perth won’t be a ghost city?
2004 Tim Flannery predicted that ‘Perth will be the 21st century’s first ghost metropolis. (2007: ‘Brisbane and Adelaide – home to a combined total of three million people – could run out of water by year’s end.’ )
Here is a press article from 2004 quoting Dr Tim Flannery talking about Perth climate & water shortage.
www.warwickhughes.com/agri16/17perthwilldie.jpg
Have readers noticed Perth region has several stations that have topped the August mean rain already? Thats by 10th August – a third of a month –
www.australianweathernews.com/data/DS1_09.HTM
Also note great info from Chris Gillham at my earlier blog –
ScoMo helpless in face of flood anger at Lismore
www.warwickhughes.com/blog/?p=6878
Page by Chris –
waclimate.net/rainfall-insurance/index.html
Chris mentions a BoM report –
Special Climate Statement 76 – Extreme rainfall and
flooding in south-eastern Queensland and eastern New
South Wales – 25 May 2022
Cunningly released quietly after the Fed Election.
There’s a link on that page to the BoM report, which mostly confirms the floods were not due to climate change but nevertheless states:
“Observations show that there has been an increase in the intensity of heavy rainfall events in Australia. The intensity of short-duration (hourly) extreme rainfall events has increased by around 10 per cent or more in some regions in recent decades, with larger increases typically observed in the north of the country.”
On my page I note … “It is doubtful the bureau has hourly rainfall records from its weather stations dating back more than a few decades, and hourly rainfall is responsible for localised flash flooding rather than broad regional flooding as caused by daily rainfall. It is noteworthy that the bureau cites unknown hourly recordings not readily accessible to the public, rather than daily recordings as used in this analysis.”
The Institute of Public Affairs has published a report on this NSW/Queensland flood analysis … www.waclimate.net/rainfall-insurance/ipa-report.pdf
Jennifer Marohasy and I have also put a joint submission to the NSW flood inquiry … www.waclimate.net/rainfall-insurance/nsw-inquiry-submission.pdf
It’ll be interesting to see if the inquiry makes the submission public (they have permission) or if the media pays any attention should they do so.
As my page states, the 2022 climate change election was strongly influenced by fresh voter television memories of the floods, resulting in the restructure of Australia’s parliament with Greens and teals turfing the Morrison Government by claiming a swag of seats.
A few weeks before the election the Climate Council also grabbed headlines with a report claiming that one in 25 Australian homes will be uninsurable by 2030 because of climate change. The report nominates 27 locations that are the most vulnerable in Australia to an increasing frequency and volume of flood events.
My analysis of those 27 locations counts the historic frequency and mm volume of 90th percentile rainfall days (10% wettest ever), the 95th percentile (5% wettest ever) and the 99th percentile (1% wettest ever). The results show …
Wettest 10% rainfall days
1915-1999 average pa frequency = 9.55
2000-2021 average pa frequency = 8.58
Wettest 5% rainfall days
1915-1999 average pa frequency = 4.82
2000-2021 average pa frequency = 4.29
Wettest 1% rainfall days
1915-1999 average pa frequency = 0.98
2000-2021 average pa frequency = 0.91
i.e. the reduced frequency of extreme rainfall days shows climate change isn’t increasing the flood risk, and it’s a pity that many voters believed otherwise when they decided it was time to create a green parliament.
Since we’re talking extreme percentiles, more important research on my page at www.waclimate.net/aws-corruption.html shows that at 70 of the 105 ACORN automatic weather stations, in the five years before and after installation their one second sensitive temperature probes registered a 27.9% increase in 90th percentile (hottest 10%) days, a 37.6% increase in 95th percentile (hottest 5%) days, and a 56.0% increase in 99th percentile (hottest 1%) days.
If anybody wants to know what’s really been happening with extreme rainfall and extreme temperatures, explore www.waclimate.net