frequency of heavy storms in Illinois Dr. Momcilo Markus Principal - - PowerPoint PPT Presentation

▶
frequency of heavy storms in
SMART_READER_LITE
LIVE PREVIEW

frequency of heavy storms in Illinois Dr. Momcilo Markus Principal - - PowerPoint PPT Presentation

Dec 09, 2022 324 likes •941 views

Accounting for the changing frequency of heavy storms in Illinois Dr. Momcilo Markus Principal Research Scientist, Illinois State Water Survey Research Assoc. Prof., Dep. of Nat. Res. and Environ. Sci. Research Assoc. Prof., Dep. of Agric. and

slide-1
SLIDE 1

Accounting for the changing frequency of heavy storms in Illinois

  • Dr. Momcilo Markus

Principal Research Scientist, Illinois State Water Survey Research Assoc. Prof., Dep. of Nat. Res. and Environ. Sci. Research Assoc. Prof., Dep. of Agric. and Biol. Eng. University of Illinois at Urbana-Champaign

slide-2
SLIDE 2

BEYOND THE BASICS SEMINAR 2020: DESIGNING FOR AN UNCERTAIN FUTURE

slide-3
SLIDE 3

Work on updating Bulletin 70 was supported by the Illinois Department of Commerce and Economic Opportunity under Grant No. 08-355061 and funded by the U.S. Department of Housing and Urban Development’s Community Development Block Grants Award No. B-08-DI-17-0001. Coordinated with IDNR Office of Water Resources. Sally McConkey, David Kristovich, Brian Kerschner, Mary Richardson, Wes Cattoor, Loren Wobig, Kexuan Ariel Wang, Lu Jin, Shaoxuan Guo, Shailendra Singh, Tom Over, Annie Peiyong Qu, Francina Dominguez, Ryan Shriver, and Lisa Sheppard

Acknowledgments

slide-4
SLIDE 4
  • Dr. Jim Angel

Illinois State Climatologist

slide-5
SLIDE 5

What is Bulletin 70?

  • Report containing the expected rainfall amounts

for selected storm durations and return periods (for example, the 24-hour, 100-year storm for a site in Illinois).

  • Many state and local agencies in Illinois required

the use of Bulletin 70 for design work after its publication in 1989.

  • The original Bulletin 70 needed to be updated

due to the observed increases in frequency and amounts of heavy rainfall events.

slide-6
SLIDE 6

IDCEO funded project on updated Bulletin 70 resulted in two reports

Angel, J. and M. Markus. 2019. Frequency Distributions of Heavy Precipitation in Illinois: Updated Bulletin 70. Illinois State Water Survey Contract Report 2019-05, Champaign, IL. Markus M., J. Angel, K. Wang, B. Kerschner, and S. Singh. 2019. Frequency Distributions of Heavy Precipitation in Illinois: Spatiotemporal Analyses. Illinois State Water Survey Contract Report 2019-10, Champaign, IL.

slide-7
SLIDE 7
slide-8
SLIDE 8
slide-9
SLIDE 9

WHAT IS UPDATED BULLETIN 70?

slide-10
SLIDE 10

“Updated Bulletin 70” = Two reports published in 2019

slide-11
SLIDE 11

“Updated Bulletin 70” = Two reports published in 2019

BULLETIN 75

slide-12
SLIDE 12

“Updated Bulletin 70”= Bulletin 75 (to be published in March 2020)

slide-13
SLIDE 13

Historical evolution of rainfall frequency standards

  • TP-40 (Hershfield, 1961)
  • Bulletin 70 (Huff and Angel, 1989)
  • Bulletin 71 (Huff and Angel, 1992)
  • NOAA Atlas 14 (Bonnin et al. 2004)
  • Angel, J. and M. Markus. 2019. Frequency Distributions of

Heavy Precipitation in Illinois: Updated Bulletin 70. Illinois State Water Survey Contract Report 2019-05, Champaign, IL.

  • Markus M., J. Angel, K. Wang, B. Kerschner, and S. Singh.
  • 2019. Frequency Distributions of Heavy Precipitation in

Illinois: Spatiotemporal Analyses. Illinois State Water Survey Contract Report 2019-10, Champaign, IL.

  • Bulletin 75
slide-14
SLIDE 14

2 4 6 8 10 12 14 16 18 1900 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 Maximum daily precipitation in inches

Aurora

Annual Maximum Daily Rainfall

(none of the 10 largest values at Aurora were observed prior to 1950)

TP40 ISWS Bulletin 70 NOAA Atlas 14 ISWS Bulletin 75

slide-15
SLIDE 15

2 4 6 8 10 12 14 16 18 1900 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 Maximum daily precipitation in inches

Aurora

Annual Maximum Daily Rainfall

(none of the 10 largest values at Aurora were observed prior to 1950)

TP40 ISWS Bulletin 70 NOAA Atlas 14 ISWS Bulletin 75

slide-16
SLIDE 16

1986-2015 minus 1901-1960 NCA4

https://science2017.globalchange.gov/

Change in Annual Precipitation

slide-17
SLIDE 17

Change in the top 1% of extreme precipitation (the 99th percentile)

https://science2017.globalchange.gov/

slide-18
SLIDE 18
slide-19
SLIDE 19

Cedar Rapids, IA, July 2008

slide-20
SLIDE 20

Grand Forks, ND, April 1997

slide-21
SLIDE 21

Des Plaines River April 18, 2013

On average, over the past 20 years in the U.S., flooding has claimed over 90 lives annually

Courtesy of Clayton Ballerine, ISWS

slide-22
SLIDE 22

Stationarity of heavy rainfall

  • Traditional assumption: Future variability will be like past
  • variability. This assumption is called “stationarity.”
  • In the light of climate change, assumption of stationarity may

not be appropriate for precipitation frequency analysis.

slide-23
SLIDE 23

Nonstationarity of heavy rainfall

slide-24
SLIDE 24

Nonstationarity of heavy rainfall

2020

slide-25
SLIDE 25

Our Solution to Observed Changes

  • Use 1948-2017 data to better represent

the current, wetter climate

  • Three times as many stations are

available from 1948 onward

  • Include a Bulletin 70 style adjustment by

giving more weight to the second half of the record

slide-26
SLIDE 26 .1 .2 .5 1 2 3 5 10 20 30 40 50 60 70 80 90 95 99 99.9 10 20 30 40

Precipitation (cm) Non-exceedence probability

Observed GLO (Single Site) WAK (Single Site) GLO (6 Sites) WAK (6 Sites) GLO (12 Sites) WAK (12 Sites)

24-Hour Precipitation Annual Maximum Frequency Analysis Results for Aurora, IL.

Markus, M., Angel, J.R., Yang, L. and Hejazi, M.I., 2007, Changing estimates of design precipitation in Northeastern Illinois: Comparison between different sources and sensitivity analysis, J. Hydrology, 347(1-2):211-222.

L-Moments Software

slide-27
SLIDE 27

10 Regions in Illinois

slide-28
SLIDE 28

176 Daily Precipitation Stations 1948-2017

slide-29
SLIDE 29

73 Hourly Precipitation Stations 1948-2017

slide-30
SLIDE 30

Process

  • Obtained and QC’d the data
  • Selected stations based on availability and

length of record

  • Calculated the expected precipitation at

selected return periods for 1 to 10 days using L-moments

slide-31
SLIDE 31

Quality Control

https://www.scirp.org/journal/PaperInformation.aspx?paperID=67664&

slide-32
SLIDE 32

Process

  • Adjusted the results from the annual

maximum series into a partial duration series using a standard approach (Langbein’s equation (1949))

  • Converted the constrained to

unconstrained using standard conversions

slide-33
SLIDE 33

Process …

  • Averaged

the station frequency values into a regional frequency analysis (RFA)

slide-34
SLIDE 34

TP-40 (Hershfield, 1961)

slide-35
SLIDE 35

NOAA Atlas 14 (Bonnin et al. 2004)

slide-36
SLIDE 36

Process

  • Calculate frequencies for sub-daily

durations using conversion factors due to limitations of hourly data

slide-37
SLIDE 37

Adjustment for Non-Stationarity

  • Ratio of the 1983-2017 RFA divided by the

1948-1982 RFA

slide-38
SLIDE 38

Confidence Intervals

slide-39
SLIDE 39

Old and New 100-Yr, 24-Hour Storm

OLD NEW

slide-40
SLIDE 40

New vs Bulletin 70 Differences in inches

slide-41
SLIDE 41

New vs NOAA Atlas 14 Differences in inches

slide-42
SLIDE 42
  • Volume I of the NCA4
  • Precipitation will continue to

increase (medium confidence)

  • Heavy precipitation events will

increase in frequency and amounts (high confidence)

https://science2017.globalchange.gov/

slide-43
SLIDE 43

Nonstationarity of heavy rainfall

2020

slide-44
SLIDE 44

Climate modeling

A climate model = an atmosphere model, an ocean model, a land model, and a sea ice model. Inputs = the concentration of greenhouse gases, the intensity of sunlight, the amount of deforestation, and volcanoes that should erupt during the simulation. Outputs = atmospheric pressure, ocean salinity, forest cover, temperature, precipitation, clouds,…

slide-45
SLIDE 45

Climate Modeling

The concentration of greenhouse gases, the intensity of sunlight, the amount

  • f deforestation, and

volcanoes that should erupt during the simulation An atmosphere model, an

  • cean model, a

land model, and a sea ice model. Atmospheric pressure, ocean salinity, forest cover, temperature, precipitation, clouds,…

Outputs Inputs Model

slide-46
SLIDE 46
slide-47
SLIDE 47

100-yr 24-hour rainfall Consistency with other approaches

slide-48
SLIDE 48

100-yr 24-hour rainfall Consistency with other approaches

slide-49
SLIDE 49

Differences between projected 100-year, 24-hour isohyetals for late-21st century and those based on NOAA Atlas 14

These results are not designed for operational use, nor do they replace the existing sources

slide-50
SLIDE 50
slide-51
SLIDE 51

Projected flooding in Cook County, IL

The 1% Annual Chance (100-year) floodplains of Upper Salt Creek (left) and Stony Creek (right) respond very differently to changes in extreme precipitation, highlighting the need for climate modeling and mapping of impacts at a local scale. SRES A2 for Mid-Century (2046-2065) and to Late-Century (2081-2100).

Managing Increases in Extreme Precipitation

In Cook County, IL: The 100-year rainfall in 2050 is The 165-year rainfall today The 100-year rainfall in 2100 is The 250-year rainfall today

SRES A2. 24-hour Precipitation

slide-52
SLIDE 52

Final thoughts on Bulletin 75

  • The frequency estimates in the bulletin represent

the present time. Climate studies indicate that the trends will continue in the future.

  • As a result of the increasing rainfall, the structures

designed based on the 2020 Bulletin 75 may not be adequate for future (e.g. 2050) rainfall magnitudes.

  • Thus, similar studies using the projected climate

modeling data need to be performed to determine future rainfall frequencies.

slide-53
SLIDE 53

Questions/comments?

slide-54
SLIDE 54

European Experiences

slide-55
SLIDE 55

Changes in Water Quantity and Quality, NCA (2018)

  • Significant changes in water quantity and quality are evident

across the country. These changes, which are expected to persist, present an ongoing risk to coupled human and natural systems and related ecosystem services.

  • Variable precipitation and rising temperature are

intensifying droughts, increasing heavy downpours, and reducing snowpack. Surface water quality is declining as water temperature increases and more frequent high- intensity rainfall events mobilize pollutants such as sediments and nutrients.

slide-56
SLIDE 56

Nutrient Loadings: Contributing factors

CLIMATE VARIABILITY WATERSHED MANAGEMENT NUTRIENT LOADINGS

  • NPS nutrient loads depend not only on BMPs, but also
  • n climate.
  • As a result, success in achieving the nutrient reduction

goals depends on climate.

slide-57
SLIDE 57
slide-58
SLIDE 58

Gaps in Existing Knowledge Tools for balancing the costs of underpreparing versus

  • verpreparing for storms/floods

in a future that may not be well predicted by the past are needed.

slide-59
SLIDE 59

Rainfall frequency sources TP-40, ISWS Bulletin 70, NOAA Atlas 14

slide-60
SLIDE 60
slide-61
SLIDE 61