The Behavior of the Flood of Record for Basins in the U.S.

Richard M. Vogel and Ellen M. Douglas

Civil and Environmental Engineering

WaterSHED Center

Tufts University

Medford, MA

Roanoke, Virginia, May 21, 2002

Spatial clustering of FOR years

FOR timing related to solar activity- first noticed by Yongquan (1993).

In the United States . . .m = minimum SSN M = maximum SSN

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16m-4

m-3

m-2

m-1 m

m+1

m+2

m+3

M-2

M-1 M

M+1

M+2

M+3

Co

rre

cte

d N

um

be

r o

f F

OR

s

Finding

• highest frequency of record floods fall within: – 1-3 years of sunspot minima (m)

– 1-2 years of sunspot maxima (M)

“Our findings indicate that 20 glacial lakes in Nepal and 24 in Bhutan have become potentially dangerous as a result of climate change," said Surendra Shrestha, Asian regional coordinator of the UNEP's Division of Early Warning and Assessment, which is based in Bangkok, Thailand.

Some Perspectives on Climate and Floods in the Southwestern U.S.U.S. Geological Survey

http://geochange.er.usgs.gov/sw/changes/natural/floods/

Figure 2. Large-scale moisture delivery pathways over North America in 4 midesason months. A, January, B, April, C, July, D, October. (Pathways data from Bryson and Hare, 1974; precipitable water vapor data from Reitan, 1960)

Figure 10. Seasonal flood-climate regions in the United States. (Modified from Baldwin and McGuinness, 1963.)

Figure 3. Average number of days per season during which thunderstorms developed in the U.S., 1951-75.A, Winter, B, Spring, C, Summer, D, Fall. (Modified from Court and Griffiths, 1983)

Figure 4. Tropical cyclones and their effect on flooding in the conterminous United States/A, Source regions of tropical cyclones, B, Tracks of selected tropical cyclones that producded flood-causing precipitation or storm surges and regions affected by precipitation from trpoical cyclones. (Modified from Gray, 1979, Cry and others, 1981, Smith, 1986, Cry, 1967, Court, 1980)

Figure 6. Atmospheric circulation during severe winter and tropical cyclone floods. (A) Composite anomaly map of 700 mbar heights (in meters) assicaiated with winter floods on rivers in central Arizona; based on 8 cases from 1947-88. (B) Same as (A) for tropical cyclones assiciated with floods on rivers in central and southern Arizona; based on 7 cases. (Modified from Ely and others 1993)

Figure 7. Primary tracks of extratropical cyclones in North America for four midseason months based on frequency of extratropical cyclones during 1951-70. A, January, B, April, C, July, D, October. (Modified from Reitan and others, 1974 and Reed, 1960)

Figure 8. Precipitation-enhancing, upper atmospheric air patterns over various parts of North America. A, Quasi-stationary trough-and-ridge patterns. B, Development and dissipation of a cutoff low. C, Movement of small-scale, short-wave troughs of low pressure through large-scale, upper atmospheric air patterns. D, Multiple meteorologic features interacting with upper atmospheric air patterns. (Modified from Muller and Faiers, 1984; Hansen and others, 1988; Maddox and others, 1980; Hansen and Schwarz, 1981.)

Figure 9. effects of average monthly precipitation and soil moisture on susceptibility to flooding at San Diego, Calif., and Tucson, Ariz. Explanation: Blue bar, precipitation (inches); gray area, available soil-moisture storage capacity (in); pale blue area, soil moisture in storage (in); red ruled area, period of greatest susceptibility to flooding. (data from Mather, 1964)

Devils Lake Fluctuations - 4000 yrs

“I don’t think that’s really a boat ramp, Luke.”

HWY. 20

looking westerly

Devils Lake, ND