Vermelding onderdeel organisatie

April 13, 2023

1

Effect of Climate Change on Urban Water System Design

Estimates Based on KNMI ’06 Climate Scenarios.

Yanina Romero

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Overview - Question - Method - Results - Conclusion

• Overview - climate change, urban water problems

• Question - climate scenarios, research question

• Methodology - tools, data selection process• Results - precipitation correlations, model

results• Conclusion - statements, further research

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Overview – Question - Method - Results - Conclusion

• CO2 emissions → greenhouse effect → global warming

• Humans are cause – 90% certainty (IPCC report)• Global warming effects irreversible – don’t

make it worse!

• Measures being taken to reduce CO2 emissions

• Climate scenarios –Consistent image of a possible future climate.

Climate Change

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Main Factors that Determine NL Climate

• Coastal location and prevailing westerly wind: sea climate• Westerly wind: mild and wet summers and

winters• Easterly wind: relative cold winters and

warm and dry summers

• Average global temperature• Warm golf stream: approx. +3 °C

Overview – Question - Method - Results - Conclusion

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August 2006Overview – Question - Method - Results - Conclusion

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Overview – Question - Method - Results - Conclusion

Schematic Overview of the Four KNMI’06 Climate Scenarios

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KNMI’06 scenarios: 2050 relative to 1990KNMI’06 scenarios: 2050 relative to 1990

Overview – Question - Method - Results - Conclusion

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• KNMI’06 climate scenarios given on a daily basis

• KNMI/RIONED assumption • Looking at the past to see the future• Research question –

Does the intensity of extreme hourly rainfall change in the same way as that

of daily rainfall?

Overview – Question - Method - Results - Conclusion

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Time duration of data sets

• Available -10-minute, hour, daily• Most relevant 10-minute data, but un-validated• Cannot use 10-minute then compare hour to daily data

Hourl

y

Daily

Overview – Question - Method - Results - Conclusion

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• What climate parameters affect the intensity of extreme precipitation?

• At the same time, need to be linked to climate scenario variables.

• Climate parameters – wind, humidity, pressure, temperature, radiation

• Sea-surface temperature (SST) for coastal cities• Correlations with precipitation – maximum daily

temperature and circulation

Overview – Question - Method - Results - Conclusion

Correlation and Selection of Climate Parameters

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• Climate scenario steering parameter – G-west• ERA-40 database (1957-present)• Make these type of plots to show relations• More scatter plots

Source: G. Lenderink, KNMI

Hourly

Daily

Pre

cip

itati

on

G-west

Overview – Question - Method - Results - Conclusion

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• Regional climate models (RCMs) input for climate scenarios

• Link precipitation to G-west• Compare daily precipitation to hourly

precipitation• Even more scatter plots...

Overview – Question - Method - Results - Conclusion

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• Temperature vs. hourly and daily precipitation are similar• Higher temperatures, higher maximum precipitation – warmer days

Hourly Daily

Overview – Question - Method - Results - Conclusion

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• G-west versus hourly and daily precipitation are similar• Maximum precipitation, lower G-west

Daily

Overview – Question - Method - Results - Conclusion

Hourly

Overview – Question - Method - Results - Conclusion

• Extreme events occur during warmer temperatures (>20 °C)

• Warmer days occur during summer months (MJJAS)• Focus on these months

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• Focus on extreme events – important for urban water system

• Took annual and seasonal maximums

Overview – Question - Method - Results - Conclusion

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• Annual maximum plots • No relation for temperature versus hourly and daily precipitation• Temperature domain is the same for both

Hourly Daily

Overview – Question - Method - Results - Conclusion

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• Apparent difference between hourly and daily • However, low correlation coefficient for both• Could use more data points • Use other methods?

Hourly Daily

Overview – Question - Method - Results - Conclusion

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Overview – Question - Method - Results - Conclusion

• Try another method to compare• Still hard to get a view of extremes• Try to look at this for one season (MJJAS)• Try taking out 0 rainfall days • Will find ratio between distributions

Daily Hourly

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• Try another method to compare• Still hard to get a view of extremes• Try to look at this for one season (MJJAS)• Try taking out 0 rainfall days • Will find ratio between distributions

Overview – Question - Method - Results - Conclusion

Daily Hourly

Overview – Question - Method - Results - Conclusion

• Find ratio of 99% and 95% daily/hourly

• Used to project ratios for ∆Tmax

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Overview – Question - Method - Results - Conclusion

• Find ratio of 95% and 99% daily/hourly• Use to project ratios for ∆G-west

• Assumption that Tmax and G-west independent

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• Based on projected ∆G-west and ∆Tmax, ratio determined

• Applied to projected daily precipitation values to get maximum hour precipitation

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date history

prec maxhp

19940810 31.3 39.5 34.1

20030610 27 32.9 32.6

20060705 26.7 33 32.7

20020709 27.4 34 31.9

19930518 27.9 32.9 27.9

20050729 59.7 74.9 20

19980611 55.2 67.3 26.4

20040623 43.9 53.5 10.5

20020820 43.8 55.7 25.1

19980914 42.2 52.7 7.1

Overview – Question - Method - Results - Conclusion

2050 W Scenario

Overview – Question - Method - Results - Conclusion

• Based distribution on rainfall distribution of historical date• Depending on historical event, maximum hour precipitation varies

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Overview – Question - Method - Results - Conclusion

• Used projected hourly precipitation results for model of Almere Haven

• Largest effect with extreme hour events (>30 mm)April 13, 2023 25

Overview – Question - Method - Results - Conclusion

• 2050 W for 09-14-1998

• Less effect with over the day distributed event

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Overview – Question - Method - Results - Conclusion

• 2050 W for 08-10-1994

• Large effect for extreme hour event

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Preliminary Conclusions

• Based on the results of this research, reason to assume different change in hourly precipitation values compared to daily values.

• However, it would be interesting to do continuing research in this.

Overview – Question - Method - Results - Conclusion

Conclusion

• Daily to hour projections made for climate scenarios

• Substantial amount of water on street with precipitation of 30 mm/hour

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Overview – Question - Method - Results - Conclusion

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Overview – Question - Method - Results - Conclusion

• Further research for non-coastal cities – precipitation/G-west

• Project to digitize historical 5-10 minute data• Perhaps same analysis for 10-minute data • Risk analysis of urban water system (Monte Carlo)• Determine return periods of hour projections• Further research for precipitation/climate variable

relations• Continued research on climate change

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