Evening star., 1935-02-03
ALPINE MODEL is USED
TOSTUDY YELLOW RIVER
Scientists in Germany Ponder Flood
Control ON Rowing Stream in.
Far.off China.

followed. Chtna's canonical histories
allege that this colossal work was un-
dertaken by the engineer Yu. His
emperor thanked him for the ingen-
ious achievement in unique way
he gave him the throne Of China.
Hereafter the dynasty of the engineer
had a brilliant part in the empires
history.
LOess Used for Levees.
Whenever the Hwang-ho changed
its course new levees would be built,
sometimes with more, sometimes with
less, effect. Consider that the dis
tance between the southern and
northern mouths is not less than 500
miles, and you will easily understand
the huge extent of the rivers devasta-
tionS.
There are no rocks, no Quarries In
the vast flats bordering the river.
What, then, could have been the ma
terial used for durable dikes? The
amazing fact is that the Chinese en-
ployed loeSS itSelf-the river demon
is beaten with his own weapons! The
construction of solid dams with this
unstable sand dust Of the desert is
technical wonder-but the Chinese
know how to do it. They spread a
matwork of certain sorghum stalks
between every two layers Of loesS.
Levees able to withstand an extraor-
dinary pressure have thus been
formed, some Of them nearly twenty
five feet in height.
The dikeS protect the land. But
the land cannot long protect the
dikes; lying lower than the river bed
and being of soft sand only, finally
the ground itself gives away and the
dikes collapse.
China appealed to the world-famous
hydraulic engineer, Prof. Hubert
Engels, Of Germany. The situation
in the Hwang-ho basin is serious.
Normally, the Yellow River at high
water carries 80 parts of water and
10 parts of loess. But last year flood
measurements near Kai-feng showed
the alarming amount of so per cent
of loess. What came rolling down
from Inner Asia was no longer a
river, but veritable lava floodl
DIR. Engels Offers Solution.
From a study of this great problem
two main opinions have been evolved.
One requires that leveeS be built high
enough to prevent the Hwang-ho from
overflowing the country even at flood
time Forced to remain in a COM
paratively narrow bed, it ought to
gain in speed and thus become strong
enough to wash the loess into the
ocean. Gradually. according to this
theory, it will deepen its channel and
thus be compelled always to follow
| the same course.
DR.. Engels offers another solution
of the problem. He would hold the
Hwang-ho to a permanent course by
surprising trick. Fix the bed at
| middle-water height only, he sug-
| gests, and do not hamper the rivers
high water from overfowing With
each inundation it will raise the sub
merged fats until they are above the
highest high-water mark.
Both these theories and some Of
their variations are being thoroughly
put to test in the Hwang-ho model
at Obernach, which, by authority of
the Chinese government, has been
constructed by the Munich Institute
| for Hydraulic Engineering The first
tests were made in 1882. The result
was most interesting; it proved that
flood control system built accord
ing to Engels' plans raised the flooded
land with the calculated speed and
that the level of the river bed deep
ened several times as fast as it did
under other methods.
Tests Prove Successful.
In recent months the experiments
have been repeated. The model has
been enlarged and the stream, which
in 1882 went straight on, now flows in
windings as rivers do in reality. Four
different series of suggestions were
tested. On the Hwang-ho in China
each of these test series would have
required five years The model fur
nishes floods to order. In six hours
one can learn facts that, on the
actual river, would require o whole
year.
The German scientists and Chinese
engineers who played with this i'm
posing toy gathered plenty of knowl-
edge. But when We turn from the
small model to the vast reality of the
Yellow River new and serious ques-
tions suddenly appear. Theoretically,
up-to-date technique might perform
any kind of task. But building levees
many hundreds of miles long with
steel and concrete is a tremendous
economic problem.
However, a people that was able to
build the Great Wall also may over
come this other Herculean task. For
thousands of years these clever and
skillful people have been fighting with
the malignant stream. Perhaps West
ern engineering will be able to help
them forget that surname they gave
to the Yellow River millenniumS ago:
"China's great sorrow since the begin
ming of time"