The Washington herald., 1922-05-16
GCheH HesukdS
Scientific.
Notes
Q77dCcame4
TUESDAY. MAY is. lsz1
RECORD FLOOD TO
ENn nv rUr~E aa


RECORD FLOOD TO
END IN JUNE =
That the record flood now Sweep-
ing the lower Mississippi and fore
cast by the government experts
from three TO four weeks before
IL started will cease its rampage In
June. is predicted by DR.. H c
frankenfeId. head of the river and
food work of the United States
Weather Bureau. -
The end of Hood season. however.
Is not yet he says. The Colorado
River is rising and 10 now In hood,
while the melting snowl OF Idaho.
Washington and BritisD Columbia
Will bring the Columbia 70 the nood
stase early In June.
f! These forecasts are based upon
/ complicated estimates from data
furnished by the river and rainfall
stations and the snowfall stations
OF the bureau which are scattered
Throughout the basins drained by
these rivers. Many variable factors
make IL no easy task for Uncle Sam
to determine what these nckie
waterways will do. --
!, The Ohio River IL the most accu-
o.
the way Of q food below the
Arkansas River. There 4, never a
great flood on the lower Mississippi
D without FIRST q flood stage on the
/ Ohio. no matter how the other
tributaries of the Fssssr Of Waters
may rise.
All the tributaries OF the MissIs-
sippi have never yet been known
20 be in the food stage at one time
The food now in progress is the
nearest approach to this condition
yet known. Predictions In the
larger rivers are chiefly based upon
the stages OF water at different
points along its course and in it's
tributaries. The records of these
| river stages along the Mississippi
go back seventy-nve years but
cannot be depended upon in present
estimates for the lower river as
there have been many changes in
the levees since that time. Sincs
1916, when the present levee system
was about completed. the records
! are more reliable. Each change
has TO be taken into account as
well as every climatic variation. yet
in the tremendous volume Of two
nfths OF the water in the United
states which passes New Orleans.
the weather Bureau can ordinarily
estimate within three inches the
exact amount Of the rise which
will occur at that point
l. Flood stages in such rivers as the
Colorado and Columbia are easier
TO predict than in the Mississippi
valley, because the conditions are
less variable. The melting snow
is the chief cause OF floods in these
Western rivers and the amount Of
snow is reported in terms of the
number Of acres which il would
cover to depth of one foot The
water content Of this is then com
puted and forecasts made from the
figures.
Upon these figures many hydro
electric concerns base their con-
tracts for the coming season for
light and power: as a short water
supply may cause them to resort 10
steam at greater expense. Irriga-
on farmers can tell from thes.
reports how much water they will
be able to have during the COM
ing season.
Forecasting the action Of the
smaller streams is a much tougher
proposition and forty-eight hours
is as far in advance as can be pre-
dicted in these cases where figures
must be based upon the raIufalI
alone. The waters rise rapidly and
now out swiftly. as in the CASE. Of
the Pueblo flood where the Weather
Bureaus warning was carried
ahead OF the onrushing waters by
galloping horseman
There are sixty-six weather Bu-
reau districts in the country win
115 all the year round river ana
rainfall stations and I25 snowfall
stations.