zim case;from el nino to la nina mugiyo hillary
TRANSCRIPT
ZIMBABWE CASE: EL NINO 2015 TO LA NINA 2016
By Mugiyo Hillary
Date: 29 August 2016
Objective
to conscience Farmers and Extension staff on 2016 La-Nina season
Background
El Niño and La Niña are opposite phases of what is known as the El Niño-Southern Oscillation
(ENSO) cycle. The ENSO cycle is a scientific term that describes the fluctuations in temperature
between the ocean and atmosphere in the east-central Equatorial Pacific. ENSO has three states -
El Niño, La Niña and Neutral - described by the cycle between above and below normal sea-
surface temperatures (SSTs) in the equatorial central and eastern Pacific.
El Niño and La Niña events tend to develop between April and June and tend to reach their
maximum strength (or peak) during December to February. An event typically persists for 9-12
months and typically recurs approximately every 2-7 years. La Niña is sometimes referred to as
the cold phase of ENSO and El Niño as the warm phase of ENSO. These deviations from normal
surface temperatures can have large-scale impacts not only on ocean processes, but also on
global. El Niño and La Niña episodes typically last nine to 12 months, but some prolonged
events may last for years. While their frequency can be quite irregular, El Niño and La Niña
events occur on average every two to seven years. Typically, El Niño occurs more frequently
than La Niña.
El Niño in 2015/16 Season
In 2015-2016 season, Zimbabwe experienced very strong negative effects of El Nino. The season
was declared as a drought year. The term El Niño refers to the large-scale ocean-atmosphere
climate interaction linked to a periodic warming in sea surface temperatures across the central
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and east-central Equatorial Pacific. The presence of El Niño can significantly influence weather
patterns in Southern Africa. El Niño means The Little Boy, or Christ Child.
La Niña 2016/17 season
According to Meteorological Services Department, MSD forecast 2016/17 season might be a La
nina seasons. La Niña means The Little Girl in Spanish. La Niña is also sometimes anti-El Niño,
or simply "a cold event." La Niña episodes represent periods of below-average sea surface
temperatures across the east-central Equatorial Pacific. Global climate La Niña impacts tend to
be opposite those of El Niño impacts.
Global and Zimbabwe La Niña Impacts
Globally, La Niña is characterized by wetter than normal conditions. In Zimbabwe wetter than
normal conditions are expected in October, November and December.
Increased flood and cyclone risk In Southern Africa, La Niña is generally associated
with increased probability of above-average rainfall from around November to April,
which corresponds to the main cropping season for most countries in the region.
Potential benefits :Enhanced rainfall could speed up the regeneration of pasture land and
lead to above-average crop production for the summer harvest. Positive effects of La
Niña on crop production would only be able to alleviate the current high levels of food
insecurity from February 2017 onwards, when the main maize crop matures and is
subsequently harvested.
Potential negative effects If excessive, precipitation would increase the risk of localized
flooding which could wash away seeds, damage or destroy standing crops, increase
livestock morbidity and mortality and damage infrastructure. There is also an increased
likelihood of cyclones forming in the Mozambique channel with associated potential
landfall and flooding.
Early actions relevant for above-average rainfall in Zimbabwe:
Plant early with effective rains (get advice from local AGRITEX AEW)
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More area to maize and other cereal production to improve food security in Zimbabwe
Crop staggering and diversification is recommended
check dam construction in high flood-prone areas,
Support agricultural extension services to prepare advice on adjustments of fertilizer and
fungicide application or early harvest. (Actual applicability and timing will depend on
meteorological forecasts, precipitation rates and crop and plant growth stage);
Use of climatic information by farmers to utilise the available moisture/rainfall
Crop insurance ie tobacco from hail
RECOMMENDED EARLY ACTIONS FOR LA NINA IN ZIMBABWE
October Mid Oct-End of Nov 2016 End of December 2016 Start of Season
Support recovery of smallholder farmers
Protect and enhance livestock production
Agritex recommended early actions in a La Nina year
Vaccination Livestock restocking
INTE
RVEN
TIO
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Input acquisitions
April to SeptStart of Agricultural Season
Crop planting-crop early with effective rains
Planning, budgeting, land
Conversely, in order to prepare for the negative consequences of localized flooding, the
following should be embedded into current response plans
Tobacco to ensure their crop from hail
Acquire more top dressing to supplement during time of leaching due to excessive rains
Small scale farmers to build extra barns to use in time of flush ripening
It is important to check dam walls and do de-silt to harvest rainfall
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NB-La-Nina does not mean reliable rainfall distribution, farmers are advised to use best
practices, water use efficient techniques, conservation agriculture, planting early with
effective rains, staggering, diversification etc
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