CAPE ARGUS - 1927,
August 2
In this article, Dr. JR Sutton, of Kimberley, one of the foremost of the
world's meteorologists, furnishes some interesting sidelights on the great
drought.
There has
been no change in the rainfall, and the climate of South Africa is what it has
been for ages. "Our luck in the weather has been out" that is all.
Rainmaking is pure quackery!
Drought in
South Africa is no new thing. We have suffered badly enough from it in the past
as we shall suffer again. In one sense there is drought over the greater part
of the country every year, that is if we define the term in the way in which it
is defined in the Meteorological Glossary issued by the Meteorological office
in London: "Dryness due to lack of rain. According to the classification
of the British Rainfall Organisation an absolute drought is a period of more
than 14 consecutive days without one-hundredth of an inch of rain on any one
day, and a partial drought is a period of more than 28 consecutive days the
mean rainfall of which does not exceed .01 inch per day," - in other words
a total fall of a quarter of an inch in a month would be a partial drought.
NEAR TO
FAMINE
On this basis
a place so well blessed with rain as Pretoria may be said to suffer from
drought, absolute or partial, in the winter of almost every year. Also, in a
season of good rains there may chance to be periods between the showers in
which no rain in measurable quantity will fall for weeks together.
As the term
is generally understood up country, however, it implies a more or less lengthy
period during which the fall is so much short of the average as not to be
sufficient to grow the crops, or water the cattle, which do fairly well at
other times; although there may not have been either sort of drought answering
to the definitions. Anyway, definitions apart, there is no doubt that the
Midlands, and beyond, have lately gone through an exceptionally bad time, and
that conditions near to famine are abroad.
Naturally the
cry that reverberates to the four winds, as it does every time that the
rainfall is deficient, is that South Africa is drying up; and the rainmakers as
usual muster on the horizon. "For wheresoever the carcass is, there will
the eagles be gathered together."
But neither
history nor statistics support the idea that the country is generally more arid
than it has been for ages. Early travelers in the parts now so distressed have
left vivid records of conditions quite as bad as anything that this generation knows.
Latrobe described the district of "Uitenhagen," when he saw it in
1816, as the most barren, desolate, unpromising desert he had seen in all South
Africa.
HALF-A-CROWN
A BUCKET
Not that he
had a very high opinion of the rest of the country. He thought that it was, and
always would be, little more than a wilderness. William Rogers, writing some 23
years ago, has told of the terrible state of things in 1859 when water was so
scarce that the people of Port Elizabeth were paying as much as 2s. 6d. a bucketful.
The bed of the Great Fish River was dry for miles. The Buffalo River had shrunk
to a mere trickle. And so on.
But 1862 was
still worse - "like which for severity nothing has been seen since." Thus,
times in the Midlands have been, and doubtless at some future time will be,
worse than the present. To tell the truth the people of South Africa, depending
on the yield of the land, are living from hand to mouth. Though betimes
seemingly in the midst of plenty they are, nevertheless, ever on the brink of
famine. The reason is to be found in the latitude, which is responsible for the
bright and sunny days we like to tell other folks about.
"Sun-kissed
Kimberley Calls" sounds well enough as a title for the most attractive
publicity booklet given to the world by any Union Town; but there are times -
as in 1897 - when the call may be to heaven, and them heaven forgive the
contributors (I was one myself) to that same booklet. It is our fortune - at
times our misfortune - to be in the latitude of the southern anti-cyclone belt.
ANTI-CYCLONIC
BELT
This belt
extends right round the earth on or about 30 deg. of south latitude; it is a
region of normally high barometric pressure and no great cloudiness. Where it
crosses the land the margins as, say, at Durban and Buenos Aires, and a few
mountainous districts. The rule is that the rainfall becomes more and more
scanty, going across the continents from east to west. there is a corresponding
belt north of the Equator.
All the hot
deserts of the world lie under these belts, the worst being north of the line,
because the land areas there spread more widely. The rainfall, such as it is,
is of summer thunderstorms type for the most part, and it comes when weather
conditions weaken the anti-cyclone influence for a while. When these conditions
are unfavourable there is drought.
Speaking a
large, conditions are more often favourable in summer than in winter over our
eastern and midland districts, since in the warm months the anticyclone tends
to shrink into subdivisions which retreat seawards. In winter there is little
of such tendency. Of late, as it happens, the anticyclone has reigned almost
supreme. Day after day for some months the barometer has, with a few slight
exceptions, stood abnormally high for the season. North and east winds have
prevailed, and very few welcome undercutting winds from the south have
appeared. And so, the drought has continued. Fortunately, there are now some
signs of improvement.
WHEN THE AXIS
SHIFTS
Anticyclones
are not yet very well understood. The International Meteorological Conference
has begun a worldwide study of temperature and pressure records which,
doubtless, will clear up many difficulties. Meanwhile it seems clear that, in
the first place, a shift of a few hundred miles north or south of the axis of
the southern anticyclone belt in winter, or of the cores of its subdivisions in
summer, makes all the difference in the resulting climatic conditions; giving,
e.g., Kimberley in any one year a fall of 31 inches, and in another only 8;
giving Aliwal North as much as 39 inches or as little as 11.
A similar
phenomenon is known in temperature northern latitudes: a shift of a few hundred
miles northward of the summer normal cyclone tracks meaning heavy rain to
Scotland, but drought to England.
In the second
place, the shifting of the belt, or its parts, is, probably, influenced, for
our good or evil, by irregular changes in the state of the Antarctic ice field.
However, let
us conclude on a brighter note. Our luck in the weather has been out, and that
badly. But in the long run four out of every five seasons are good enough; and
the evils of the odd fifth are largely of our own making; due to a pernicious
optimism which takes no thought for the future in the light of the past.
Overstocking and the ruthless cutting out of the thorn bush are, I am told,
rampant everywhere. Hence, when the rains fall, we get no more than we deserve.
The assertion
that the country has lost 30 million pounds by one season’s drought really
means that farmers have been trying to make too much. Droughts are due to
peculiarities of the atmospheric circulation over a whole hemisphere of the
earth. They are not to be escaped; and the trumpery quack devices of the
rainmaker against them are futile. But is unavoidable the time will come when
their approach will be foretold months beforehand. That time will be when our
politicians can be got to see that the problems of long-range weather
forecasting is infinitely more important than the trifles they like to wrangle
about.