THE RELEVANCE OF OLD FLOODS

TO MODERN HYDROLOGY

Geographisches Institut | Johannes Gutenberg-Universität Mainz | May 18, 2017

HOW MUCH TIME IS NEEDED

TO TRULY KNOW A RIVER?

THE RHINE IN MAINZ

Source: Fredrik Von Erichsen/AFP/Ge!y Images

THE MISSISSIPPI IN MINNEAPOLIS

THE MISSISSIPPI DURING THE 1988 DROUGHT

WINNIPEG, CANADA

THE RED RIVER OF THE NORTH

THE RED RIVER OF THE NORTH

Source: Morningstarphoto

0.5 METRES PER KILOMETER

THE RHINE THE RED0.08 METRES PER KILOMETER

STREAM GRADIENT

LAKE AGASSIZ

1950

DURING EXTREME CASES, THE FLOOD ZONE OF THE RED RIVER CAN EXTEND 40 KM WIDE.

“ ”BACK IN 1997, THE WATER SPILLED ONTO THE FLAT PRAIRIE

LIKE AN OPEN BOTTLE OF CHOCOLATE MILK

THAT HAD TIPPED OVER ON THE KITCHEN TABLE.

Roy MacGregor The Globe and Mail, August 7, 2015

Source: Greg Brooks

1997

River diversion

Main channel

Source: Dr. Greg Brooks, Geological Survey of Canada

IN THE 1960s, WINNIPEG BUILT A 47-KM LONG DIVERSION CHANNEL THAT DIVERTS RED RIVER AROUND THE CITY.

GRAND FORKS, NORTH DAKOTA

THE 1997 RED RIVER FLOOD (AND FIRE) CAUSED MORE THAN $3.5 BILLION IN DAMAGES.

WINNIPEG GRAND FORKS

RIVER MEMORY

FLOODS — BY THEIR NATURE — ARE RARE

EVENTS.

EVALUATE VULNERABILITY

JUDGE INFRASTRUCTURE

BE MORE AWARE OF NATURE’S POTENTIAL

A DEEP ‘RIVER MEMORY’ IS ESSENTIAL TO:

2UNCOVERING ANCIENT FLOODS

1GAUGING FLOOD RISKS

Source: Roland Schlager/EPA

Source: AON Benfield, 2016 Annual Global Climate and Catastrophe Report

FLOODS HAVE BEEN THE COSTLIEST PERIL FOR THE PAST 4 CONSECUTIVE YEARS,

AND CAUSED $62B IN LOSSES

GLOBALLY IN 2016.

Source: Guha-Sapir et al, 2015, Annual Disaster Statistical Review 2015.

OVER THE PAST DECADE FLOODS KILL

NEARLY 7000 PEOPLE WORLDWIDE EACH YEAR.

“ ”NO ONE IS GOING TO MOVE ST. LOUIS

JUST BECAUSE IT HAPPENS TO BE IN THE RIVER.

David Johnston The Ohio State University

The Quad Cities River Bandits and the Peoria Chiefs play a baseball game April 20, 2011 inside Modern Woodmen Park in Davenport, Iowa.

SACRAMENTO RIVER, CALIFORNIA

WHAT ARE THE RISKS POSED BY FUTURE FLOODS?

FFA(Flood Frequency Analysis)

FFACITY PLANNING INSURANCE PRICING MANAGEMENT PLANS

NEAR TUCSON, ARIZONA

THE RILLITO RIVER, TUCSON

“ ”THE 100-YEAR FLOOD HAS COME AND GONE

SO, BY ALL RIGHTS, TUSCONANS SHOULD ENJOY ANOTHER CENTURY

OF GREAT SOUTHWEST WEATHER.Metropolitan Tucson Convention and Visitor’s Bureau

Sent immediately a!er a severe flood

FREQUENCY

MAGNITUDEsmall large

common

rare

EMIL GUMBEL (MATHS)

“ ”FOR THE TWO OR THREE EXTREME FLOODS, THE RETURN PERIODS ARE BASED

ON A FEW OBSERVATIONS, AND CONSEQUENTLY, THE AGREEMENT

IS NOT VERY GOOD.Gumbel, 1941

The Annals of Mathematical Statistics

An aerial image of downtown shows flood-affected areas June 13, 2008 in Cedar Rapids, Iowa

EVEN WITH KNOWLEDGE OF A HISTORICAL FLOOD IN 1851, THE 2008 FLOOD IS STILL NEARLY TWICE AS LARGE

AS ANY OTHER FLOOD ON RECORD.

0

1000

2000

3000

4000

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

Discharge (m3/s)

PASSAU, GERMANY

Source: Christian Gries

“ ”FOR GREATER FLOODS, THE MAXIMUM KNOWN FLOOD ELEVATION

IS MORE IMPORTANT THAN ITS RECURRENCE INTERVAL. IF THE FUTURE IS LIKE THE PAST,

THE OLDEST AND SIMPLEST IDEA IS THE BEST - A FUTURE FLOOD COULD RISE AT LEAST AS HIGH

AS THE PREVIOUS MAXIMUM.James Eychaner

Lessons from a 500-year Record of Flood Elevations

2UNCOVERING ANCIENT FLOODS

WHAT ARE THE RISKS POSED BY FUTURE FLOODS?

THE FIRST STREAM GAGE IN THE UNITED STATES WAS ESTABLISHED AT EMBUDO, NM IN 1889.

PALEOFLOOD HYDROLOGY

VIC BAKER, UNIVERSITY OF ARIZONA

“ ”PALEOFLOODS ARE PAST OR ANCIENT FLOODS

THAT OCCURRED WITHOUT BEING RECORDED BY EITHER (1) DIRECT HYDROLOGICAL MEASUREMENT DURING THE COURSE OF OPERATION (KNOWN AS INSTRUMENTAL

OR “SYSTEMATIC” RECORDING) OR (2) OBSERVATION AND/OR DOCUMENTATION

BY NON-HYDROLOGISTS.Victor Baker (2008)

Paleoflood hydrology: Origin, progress, prospects

COLORADO RIVER

RED RIVER OF THE NORTH

Source: Katie Rampala

Source: Robert Jarre!, US Geological Survey

SLACKWATER DEPOSITS

Source: Greenbaum et al., (2014), Water Resources Research.

44“100-YEAR FLOODS”

IN THE PAST 2100 YRS.

“ ”OUR RESULTS INDICATE THAT VERY LARGE FLOODS

(A) ARE MUCH MORE FREQUENT THAN INDICATED BY PREVIOUS ESTIMATIONS

WHICH WERE BASED EXCLUSIVELY ON ANALYSIS OF THE MEASURED, SYSTEMATIC GAGE RECORD, AND

(B) THEIR FREQUENCY HAS INCREASED DURING THE LAST 500 YEARS.

Greenbaum et al, 2014 Water Resources Research

PMF(Probable Maximum Flood)

THE ESTIMATED DISCHARGES FOR THE TWO LARGEST PALEOFLOODS ARE BIGGER THAN THE PROBABLE MAXIMUM FLOOD FOR THE MOAB VALLEY.

“ ”WHAT SHOULD BE DONE IF A STIPULATED PMF VALUE

(WHAT IS THEORIZED TO BE THE FLOOD THAT WILL RESULT FROM THE “MOST SEVERE COMBINATION OF CRITICAL

METEOROLOGICAL AND HYDROLOGIC CONDITIONS THAT ARE REASONABLY POSSIBLE”)

IS DISCOVERED TO BE CONTRARY TO WHAT ACTUALLY EXISTS IN NATURE?

Greenbaum et al, 2014 Water Resources Research

Source: Flickr\Liren Chen

THE RED RIVER OF THE NORTH

WINNIPEG GRAND FORKS

GRAND FORKS

1872

WINNIPEG

1812

FORT GARRY, HUDSON’S BAY COMPANY

MAY 3 1826

THE RIVER ROSE SIX FEET LAST NIGHT PERPENDICULARLY ,

SEVERAL TENTS ARE NOW PITCHED UPON THE MOST ELEVATED SPOTS:

TERROR IS STRONGLY DEPICTED ON EVERY COUNTENANCE.

“ ”

David Jones Journal May 1826

MAY 5 1826

THE RIVER OVERFLOWED ITS BANKS

EVERY WHERE, AND CARRIED THE ICE WITH GREAT VELOCITY TO A GREATER DISTANCE FROM ITS COURSE,

THAN HAD EVER BEEN SEEN BEFORE BY THE OLDEST INHABITANTS.

“ ”

Red River Journal May 1826

MAY 16 1826

THE WHOLE FACE OF THE COUNTRY, BOTH BELOW AND ABOVE OUR ENCAMPMENT

IS COVERED WITH WATER, AND IN THIS WINDY WEATHER, LOOKS LIKE

AN IMMENSE LAKE IN A STORM.

“ ”Red River Journal

May 1826

SIR SANFORD FLEMING

THE LARGEST FLOODS ARE KNOWN FROM HISTORICAL ACCOUNTS AND POST HOC SURVEYS OF LOCAL ELDERS.

Source: Manitoba Conservation and Water Stewardship

0

60,000

120,000

180,000

240,000

2006 1996 1979 1950 2011 1861 2009 1997 1852 1826

discharge (cfs)

historical reports river gauges

1950

Source: Greg Brooks

1997

QUERCUS

√

24

OAK TREE RINGS (NORMAL ANATOMY)

91Source: St. George and Nielsen, The Holocene, 2003

1826

19

700-YR FLOOD

… ALTHOUGH THE 1826 FLOOD DEVASTATED THE FLEDGLING

RED RIVER SETTLEMENT, IT ALSO LED TO THE DEVELOPMENT OF

A SUPERIOR LEVEL OF FLOOD PROTECTION

FOR MODERN WINNIPEG…

“ ”

St. George and Rannie Canadian Water Resources Journal, 2003

HOW MUCH TIME IS NEEDED

TO TRULY KNOW A RIVER?

Source: Fredrik Von Erichsen/AFP/Ge!y Images

“ ”(RHENUS) FLUVIUS GALLIAE QUI GERMANOS A GALLIA DIVIDIT. (THE RHINE IS A) RIVER OF GAUL, WHICH DIVIDES

THE GERMANIC PEOPLE FROM GAUL.Maurus Servius Honoratus

Commentary on the Aeneid of Vergil 4th Century CE

EVALUATE VULNERABILITY

JUDGE INFRASTRUCTURE

BE MORE AWARE OF NATURE’S POTENTIAL

A DEEP ‘RIVER MEMORY’ IS ESSENTIAL TO:

VIC BAKER, UNIVERSITY OF ARIZONA

THE HISTORY OF PAST FLOODS, NOT THE HISTORICAL IDEALIZATION OF THEIR FUTURE POSSIBILITIES,

IS THE UNDERSTANDABLE BASIS UPON WHICH PEOPLE

MAY BE GUIDED TO EFFECTIVE ACTION.

“ ”

Baker et al., 2002 The Scientific and Societal Value of Paleoflood Research

MANITOBA MUSEUM

103Source: St. George and Nielsen, The Holocene, 2003

1826

19

MANITOBA MUSEUM

“ ”Believe me, you will find more lessons in the woods than in books. Trees and stones will teach you what you cannot learn from masters.ST. BERNARD OF CLAIRVAUX 1090 - 1153 CE

@sco!stgeorge