••••
COME R AI N OR S H I N E
How is the season
progressing?
> CONTINUED FROM PAGE 49
The map on the right indicates
the NDVI (Normalised Difference
Vegetation Index) of South Africa
for February 2017, compared to
the long-term February situation.
This index is calculated using a
formula and space observation
satellites are used in the calcu-
lation of the index. It is evident
that parts of the Free State,
Northwest, Limpopo and the
Northern-Cape are much greener
than the rest of the country. It
means that more active growth
has been experienced than during
the corresponding long-term
period. The good rainfall during
January and February 2017 was
the main reason. It is evident that
Mpumalanga, KwaZulu-Natal,
the Eastern-Cape and parts of the
Western-Cape have received less
rain and are dryer than the long-
term average. The very dry areas,
where almost no vegetation can
be seen, are also clearly visible on
the map.
We can therefore look back on a
favourable season in the tradition-
al Senwes area. However, as far as
wheat is concerned, prospects are
not as favourable for the coming
NDVI OF SOUTH AFRICA FOR FEBRUARY 2017
season. Although this is the time
during which we would like to
capture moisture, autumn rains
have not been adequate.
INDICATORS FOR THE REST OF THE
2016/2017 SEASON
Indications of an El Niño-year
coming up are increasing. The
sea temperature in the NINO3-4
area of the Pacific Ocean is getting
warmer. The so-called NINO 3-4
index indicates the difference of
the sea temperature compared to
the long-term average. The record
high sea temperature of the previ-
ous season is evident in the map
below. A neutral status is indicated
in terms of El Niño/La Niña vir
this season.
The Australian Government
Bureau of Meteorology does
extensive research on the El
Niño/La Niña phenomena and
reflects the status of the episodes
as “ watch”, as indicated in the
diagram below. There should be
more certainty about the season in
terms of an El Niño or La Niña-
status in five months time.
SUMMARY AND CONCLUSION
Although the season commenced
on a negative note in particularly
the western parts of the traditional
Senwes area of operation, it ended
on a very positive note. Good
crops are expected and indications
are that the new season will com-
mence with good sub-soil mois-
ture levels.
50
APRIL/MAY 2017 • SENWES Scenario