http://water.usgs.gov/floods/events/2015/Joaquin/HolmesQA.html
Is this flood due to climate change?
USGS research has shown no linkage between flooding (either increases or decreases) and the increase in greenhouse gases. Essentially, from USGS long-term streamgage data for sites across the country with no regulation or other changes to the watershed that could influence the streamflow, the data shows no systematic increases in flooding through time.
A much bigger impact on flooding, though, is land use change. Without proper mitigation, urbanization of watersheds increases flooding. Moreover, encroachment into the floodplain by homes and businesses leads to greater economic losses and potential loss of life, with more encroachment leading to greater losses.
…
Is this flooding in South Carolina truly a 1000-year flood?
While this certainly was a catastrophic flood with lots of damage and tragic loss of life, USGS provisional data and preliminary analysis show NO indication that a 1000-year flood discharge occurred at any USGS streamgages. However, based on that analysis, it does appear that the USGS streamgage on the Black River at Kingstree, SC and the one on the Smith Branch at Columbia, SC both measured peak floods in the neighborhood of a 500-year flood. Currently, there appear to be a few more streamgages experiencing a 25-year to 50-year flood, but the majority of USGS streamgages had flood peaks that were less than 10-year floods. USGS will have more accurate estimates of the flood probabilities out in the coming months, as the engineers and scientists in South Carolina take time to do more careful analysis of the statistics.
…
I heard that the river flow through downtown Columbia was 4 times the historic maximum; maybe that was close to the 1000-year flood?
The provisional peak flood flow that USGS measured for the Congaree River in Columbia was 185,000 cubic feet per second (cfs) on Sunday, October 4, 2015. The maximum recorded in history was 364,000 cfs in 1908, which is almost double what was experienced in this current flood.
In the 1930s, though, reservoirs were built in certain parts of the Congaree watershed upstream of Columbia, which makes a flood of 364,000 cfs unlikely. However, even in the 75 years since the construction of those reservoirs (see the peak record here), there have been floods that approach the 2015 flood. For example, in 1964 the peak discharge was 142,000 cfs, and in 1977 the peak discharge was 155,000 cfs.
So, if only the data from last 75 years are considered, this flood is the largest in that period, but not four times the historic maximum.
#
More here: http://water.usgs.gov/floods/events/2015/Joaquin/HolmesQA.html
#
Related Link:
Real Science website on alleged 1000 year weather events: ‘Your odds of winning the lottery are low. Odds of someone winning the lottery are good.
Many climate experts don’t understand the difference.’
3 Responses
For too many years now, we have been bombarded with one climate scare after another. They always are shown to be false. Yet more of the same happens again and again and again. Well, the time has come to tell the “boy” to “stop crying wolf”.
How can this be done?
Imagine if we could bring together in, say, London, all the world’s prominent climatologists who believe it is essential that all the climate science is assessed, not just the science relating to ‘man-made warming’, which is what the IPCC does? Imagine holding such a gathering prior to Paris COP21 in December, at which the global media is presented with the real climate facts and observations that contradict the alarmist claims… about CO2, about surface instrument temperature data, about satellite temperature data, about model trends and actual trends, about sea levels, about Arctic ice, about Antarctic ice, about hurricanes, about so called “ocean acidification”, about numerous alarmist predictions, etc etc etc.?
What an incredible impact it would have on Paris COP21. It would be equivalent to the impact the “climategate emails” had in Copenhagen back in November/December 2009… probably more so.