Robert Muir

[Robert Muir @RobertMuir_PEng]

Missing & remembering you Allan Riley - thank you for sharing your story Al, dad, gramps ... https://t.co/vZTOW7JiYb #RemembranceDay #LestWeForget #BattleoftheAtlantic

[Robert Muir @RobertMuir_PEng]

@therealmrbench @BonnieCrombie Often media & sometimes politicians get it wrong when it comes to what causes flooding - sometimes they do corrections when they look at the data: https://t.co/LF8qLXigYf but often flooding is still blamed on more intense/frequent storms NOT observed in S.Ontario or Canada data

[Robert Muir @RobertMuir_PEng]

@therealmrbench @BonnieCrombie The climate in terms of extreme rainfall has not changed in 30 years based on @environmentca Engineering Climate Datasets for Southern Ontario, including Mississauga/ Pearson A climate station https://t.co/vgo3P04fPQ

[Robert Muir @RobertMuir_PEng]

@RogerPielkeJr @StephenMStrader Disappointing how the article got that concept wrong.

[Robert Muir @RobertMuir_PEng]

@RogerPielkeJr Thanks Roger. Similar trends in Canada based on long term @environmentca data: https://t.co/Pc5aHVrQzL ... some report on a shorter time periods starting in the late 1940's or 1970's and miss the earlier highs: https://t.co/kKvvXUcPV2 @TorontoStar #climatechange #extremeweather

[Robert Muir @RobertMuir_PEng]

@gavenuti @350Canada @JustinTrudeau Can @350Canada or @JustinTrudeau point to data showing wind or other extreme weather is hitting 'harder' and 'more often'? The @Canada in a Changing Climate Report did not have any analysis of extreme wind & said no evidence of observed more extreme rain (https://t.co/dRUxD8Cfle)

[Robert Muir @RobertMuir_PEng]

@gavenuti @350Canada @JustinTrudeau Recent storm was a tragedy. But the NRC's recent benefit cost guideline for flood control shows that extreme rainfall has not been increasing across Canada (https://t.co/7YGPeRMZbb) & @environmentca AHCCD data shows many city extreme temps not increasing (https://t.co/Pc5aHVrQzL

[Robert Muir @RobertMuir_PEng]

@mdhDuBois @arbol_y_agua Hi Marccus, here is a link: https://t.co/TbtP3Gsshc - GSI costs are in Appendix F Annex F1. I'd think depending on local goals & benefits pursued, & varied site constraints (sanitary I&I/chlorides in WHPAs/shallow rock...) or opportunities, different approaches are preferred.

[Robert Muir @RobertMuir_PEng]

@highlyanne @nanditabasu2 @StormWater_TO @NPR @EcoGreenQueen @PSUstormwater @mdhDuBois Not sure how GI can "take the top off big events" ? Sized to handle frequent small events GI gets filled in the rising limb of hydrographs & volume is not available for peak shaving. A better argument could be to reduce volumes cumulatively. Conveyance for big events is needed.

[Robert Muir @RobertMuir_PEng]

@highlyanne @NPR @EcoGreenQueen @PSUstormwater @mdhDuBois Unfortunately not a solution for most urban flooding challenges (50+ year old systems built to low standards) where conveyance/control of larger events is needed. Retrofitting large areas financially not sustainable (re lifecycle costs) - Ontario example: https://t.co/KeKwKc7gLz

[Robert Muir @RobertMuir_PEng]

@AndrewSiffert @IPCC_CH Hi Andrew, the new @NRC_CNRC cost benefit guideline for flood control reviews rain intensities in Canada. Overall 100-year intensities decreased especially over short durations. In southern Ontario, since 1990 100-year intensities are overall unchanged: https://t.co/7YGPeRMZbb

[Robert Muir @RobertMuir_PEng]

@terencecorcoran Good point Terence. Flood peaks are up and down in Canada (https://t.co/AWlYzxeOQI). @Canada 2021 National Issues report explains increased losses since the 1980's were due to 'growing exposure and rising asset values': https://t.co/6u6cNZhCR4 #flooding #climatechange

[Robert Muir @RobertMuir_PEng]

@RogerPielkeJr Unfortunate 'trickle-down effect' is that tools like https://t.co/isdmRNYfJC from @environmentca use scenarios to guide other analysis, but with no consideration of the implausibility.

[Robert Muir @RobertMuir_PEng]

@gavenuti @ClimateReality The National Research Council of Canada's new cost-benefit guideline for flood control reviews trends and shows some regions have flat or decreasing trends: https://t.co/7YGPeRNx0J - overall, 100-year storms are not more severe based on @environmentca Engineering Climate Datasets

[Robert Muir @RobertMuir_PEng]

@vaughanvoice22 @treebeing @patrickbrownont @StormhunterTWN @BEMOprepared @regionofpeel @CityBrampton @BramptonFireES @PeelPolice @Peel_Paramedics @CNRC_NRC With climate change winter min, mean & max temps are up https://t.co/pqsMxFQbjQ which increases winter infiltration (shorter frozen periods), increasing winter flow but lower spring peaks - points to lower risk (re peaks). @GuelphEng shows this for urban & rural systems too

[Robert Muir @RobertMuir_PEng]

@vaughanvoice22 @treebeing @patrickbrownont @StormhunterTWN @BEMOprepared @regionofpeel @CityBrampton @BramptonFireES @PeelPolice @Peel_Paramedics @CNRC_NRC Warmer winters can result in smaller spring peaks (lower flood risk) in melt-dominated systems - check out: https://t.co/AWlYzxeOQI (Canada) or: https://t.co/x5OJzYo0vA (southern Ontario) - warmer means more winter infiltration & smaller snowpack = smaller peaks. Hope that helps

[Robert Muir @RobertMuir_PEng]

@treebeing @patrickbrownont @StormhunterTWN @BEMOprepared @regionofpeel @CityBrampton @BramptonFireES @PeelPolice @Peel_Paramedics @vaughanvoice22 Homes have a variety of berms (dykes) flanking the Credit River, dating back decades due to the known risk (see streetview). When CHIC designed 407 ETR crossing downstream in the 1990's this risk was already well known.

[Robert Muir @RobertMuir_PEng]

@treebeing @patrickbrownont @StormhunterTWN @BEMOprepared @regionofpeel @CityBrampton @BramptonFireES @PeelPolice @Peel_Paramedics @vaughanvoice22 Not climate change - its inadequate historical flood hazard management. This has been a high risk flood damage centre for a very long time. Existing berms protecting those properties have limits. Homes would not be built there (in a regulated floodway) under today's standards.

[Robert Muir @RobertMuir_PEng]

@vaughanvoice22 @treebeing @patrickbrownont @StormhunterTWN @BEMOprepared @regionofpeel @CityBrampton @BramptonFireES @PeelPolice @Peel_Paramedics Recent National Research Council of Canada @CNRC_NRC guidelines on flood control cost-benefit analysis do not show changes in significant rainfall in southern Ontario: https://t.co/7YGPeRMZbb. Impervious surfaces must be well-managed to avoid more risk: https://t.co/rIFMY25M0o

[Robert Muir @RobertMuir_PEng]

@RogerPielkeJr Good to know as many estimate extreme rain shifts w/ temperature. So why does @Canada plot RCP 8.5 as default scenario that paper shows "lies far outside the range of plausible scenarios", and has no option for more plausible SSP 3.4 range (@Canada calls RCP 4.5 'low carbon').