1. November 27
Paleofloods

2. Source: AP Photo/Carolyn Kaster

3. INSURED LOSSES
DUE TO FLOODS EXCEEDED
$6.4 B
IN 2010.
Source: Swiss Re

4. WORLDWIDE
11,027
PEOPLE WERE
KILLED BY FLOODS.
Source: Swiss Re

5. Annual losses* due to floods in the United States 2005
1993
1972
1927
Source: National Weather Service
* adjusted for inflation

6. PAST BEHAVIOR FUTURE RISKS

7. Photograph: skooksie

8. “100-year flood”

9. The 100-year flood refers to a flood that has a 1% chance
of being equaled or exceeded in any single year.

10. “ NG ”
O
The 100-year flood has come and gone, so, by all rights,
R
Tucsonans should enjoy another century of great Southwest weather.
W
Metropolitan Tucson Convention and Visitor’s Bureau
Sent immediately a er a severe flood

13. Paleoflood hydrology uses physical evidence le behind
on the landscape to make inferences about past floods
that were not directly observed or recorded by humans.

14. Photograph: David Snyder
Slackwater deposits Fine-grained sediments laid down by floodwaters

15. “
The forts now stand like a castle of romance in the midst of
an ocean of deep contending currents, the water extending
for at least a mile behind them, and they are thereby only
approachable by boats and canoes.”
Francis Heron
Hudson Bay Company, 1826
St.. George and Rannie, Canadian Water Resources Journal, 2003

16. scarring
microclimatology
injury
“flood rings”

17. Reading
St. George (2010), Tree rings as paleoflood and
paleostage indicators. In Stoffel et al., (eds.),
Tree Rings and Natural Hazards.

18. FLOOD SCARS

19. Photograph: Mark’s Postcards from Beloit

20. Photograph: NDSU Ag Comm

21. FLOOD SCARS
The timing of the flood can be determined by counting the number
of rings between the scar and the outside ring, and the height of
the scar represents the minimum elevation of high water.

22. INJURY

23. Floods can damage trees by tilting or partial uprooting
or can uproot them completely, causing their death.

24. MICROCLIMATE
Source: Alex Drainville

26. Photograph: Alex Source

27. Source: ouelle e001.com

28. FLOOD RINGS

30. Winnipeg Manitoba

31. Winnipeg
The name Winnipeg is a transcription of
the western Cree word wi-nipe-k meaning
"muddy waters"

32. Source: Greg Brooks

34. Source: U.S. Coast Guard, Lt. Brendan Evans

35. Source: Greg Brooks

36. Grand Forks, North Dakota 1997 flood and fire

38. Source: Ma hew Bietz

39. Lake Agassiz

41. How large can Red River floods get and how o en
do the large ones occur?
Are there geological processes that may be
changing the Red River flood hazard?
What are the geological controls that govern the
character of Red River flooding?

42. Instrumental and historical estimates of major Red River floods

43. Erik Nielsen Manitoba Geological Survey

45. Source: Greg Brooks

49. 2008

50. 1875

51. Source: Erik Nielsen

52. 54
Source: Erik Nielsen

58. “
The forts now stand like a castle of romance in the midst of
an ocean of deep contending currents, the water extending
for at least a mile behind them, and they are thereby only
approachable by boats and canoes.”
Francis Heron
Hudson Bay Company, 1826
St. George and Rannie, Canadian Water Resources Journal, 2003

60. Source: St. George and Nielsen, Geographie Physique et Quaternaire, 2002

61. In hydrology, flood observations reported as having occurred
above some threshold are known as censored data sets.

63. Photograph: USGS
1979 Red River flood Drayton, North Dakota

64. Source: St. George and Nielsen, Geographie Physique et Quaternaire, 2002

66. St. George et al. (2002), Tree-Ring Research

67. How large can Red River floods get and how o en
do the large ones occur?
Are there geological processes that may be
changing the Red River flood hazard?
What are the geological controls that govern the
character of Red River flooding?

68. 350 years of Red River floods
Source: St. George and Nielsen, The Holocene, 2003

69. TREES AS PALEOFLOOD INDICATORS
Strengths and limitations

70. Photograph: David Snyder

71. Redrawn from Stahle (1990)

72. Source: Steffano A ardi

73. scarring
microclimatology
injury
“flood rings”

74. GEOG5839
XT C L AS S
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