Table of Content
FORWARD
1.0
Introduction
2.0
Evidence of Climate Change
2.1 Rainfall Onset and Cessation
2.2 Hail Frequency
2.3 Mean Temperature
3.0
Synoptic Features
3.1 Surface Pressure
3.2 Inter-Tropical Discontinuity (ITD)
3.3 El-Nino
4.0
4.1
4.2
4.3
4.4
4.5
Temperatures
Hot Season Maximum Temperatures
Hot Season Maximum Temperature Anomaly
Cold Season Minimum Temperatures
Cold Season Minimum Temperature Anomaly
Annual Mean Temperature Anomaly
5.0
Solar Radiation
6.0
6.1
6.2
6.3
6.4
6.5
Rainfall
Cumulative Annual Rainfall
Rainfall Anomaly
August Rainfall Anomaly
Rainfall Months
Little Dry Season
7.0
Dust Haze
8.0 Extreme Weather Events
8.1 Wind Speed
8.2 Temperature
8.3 Rainfall
9.0 Socio-Economic Impacts
9.1 Agriculture
9.2 Health
9.3 Education
9.4 Hydrology
9.5 Aviation
10.0
Summary
11.0
Climate outlook 2013
12.0
Annex: The Great Floods of 2012
12.1 Lagos State
12.2 Nigeria
12.3 Global
13.0
Sample Flood Pictures
1
FOREWORD
Climate change is real and its consequences will be with us for the greater part of
this century. If appropriate measures are taken now to stem the increase in the emission of
Green House Gases (GHG) into the atmosphere that is responsible for the global warming
then there will be a reversal of the consequences. The Intergovernmental Panel on Climate
change (IPCC) has established through its science based research that the effect of global
warming will linger for longer period if the present trend of GHG emission is not curtailed.
The Intergovernmental body has also shown that the anthropogenic activities has
contributed significantly to the variations and changes observed in the world climate system
since the post industrial revolution era apart from the contributions of natural climate
modifiers such as continental drift, volcanoes, ocean currents, earth’s tilt, comets and
meteorites. All living things are affected by the climate systems and in particularly by the
climate extremes which threatens safety of lives and property and sustainability of socioeconomic activities. Since weather and climate know no natural, geographical, political or
disciplinary boundaries, cooperation amongst relevant institutions become very necessary
to put in place a robust and effective mitigation and adaptation measures to the variability
and change of the climate systems in order to achieve the much desired stabilization. It is
therefore not surprising that climate change remains one of the greatest challenges of our
time towards attainment of sustainable economic development and calls for reinforced
interdisciplinary cooperation to stem its devastating consequences.
It is important to mention here that climate systems are not all about the extreme
events and the associated devastating effects. There are also benefits associated with
climate systems especially when considered as a resource that if factored into decisionmaking and development and policy formulation, produces beneficial results to mankind. It
is in recognition of this that the World Meteorological Organization (WMO) established the
Global Framework for Climate Services (GFCS).The main goal of GFCS is to “enable better
management of the risks of climate variability and change and adaptation to climate
change, through the development and incorporation of science-based climate information
and prediction into planning, policy and practice on the global, regional and national
scale’’ (World Climate Conference-3). Investment therefore in climate services translates to
2
economic prosperity for both citizens and institutions through appropriate adaptation
strategies to climate variability and change. It is noteworthy to mention that adaptation to
risks and opportunities from climate vulnerability and change especially to the most
vulnerable communities saves life and property and creates wealth for the citizenry.
The 2012 Nigeria Climate Review has shown very interesting features in the
variability of the atmospheric elements compared to their long term averages. Notable
amongst the observed features are positive rainfall anomaly recorded in most parts of the
country. Indeed the Northeast zone recorded positive anomaly for the first time in the last 5
years and the highest anomaly in the last 10 years. The above normal rainfall resulted in
unprecedented flooding which caused loss of lives and properties. The magnitude of the
losses recorded could be attributed to non adherence of relevant Agencies to the early
warning provided by NIMET with very good lead time. The Little Dry (Harmattan) Season
was very pronounced in the Southwest. Its severity and the duration was the highest
recorded in the last 5 years. Most states in the North also recorded above normal day time
temperatures at early part of the year which increased the discomfort level.
Nigeria Climate Review Bulletin is one of the many science based publications of
NIMET geared towards informing all stakeholders and the general public of the variations in
climatic elements for better decision making and policy formulations. It is produced yearly
and provides wealth of information on the climate of the year under review. It also
highlights in particular the temporal and spatial variations of temperature, rainfall, dust
outbreaks, harmattan season and hailstone occurrence in the course of the year. The
publication also contains catalogue of extreme weather events and the socio-economic
benefits of climate variations and changes. Government will continue to support and
encourage such scientific based publication that will help achieve the transformation
Agenda and the Millennium Development Goals (MDGs).
I highly recommend the Nigeria Climate Review Bulletin for all scientists and
practitioners especially those who seek adaptation to risks and opportunities from climate
variability and change especially to the most vulnerable sectors of the economy and
communities to climate related hazards.
3
1.0
INTRODUCTION
The climate of Nigeria has shown considerable temporal and spatial shifts in its variability
and change. Extreme climate and weather events (drought, flood, heatwaves, ocean surges,
etc) have become more regular. The impacts of extreme weather and climate may be
gradual but they are destructive to lives and property, negatively impact on the economy.
Floods have become a perennial challenge with increasing intensity each year, leaving
colossal losses and trauma. The low-lying coast of the country experiences perennial
inundation due to ocean surges and strong tidal waves.
The 2012 Nigerian Climate Review bulletin has added new climate indicators such as ‘rainfall
months’ anomaly, extreme meteorological parameters, etc., in addition to standard
statistically examined climatic elements (maximum and minimum temperatures, rainfall
amounts and patterns of onset and cessation of rainfall). This innovation is to provide
scientists and experts in the socio-economic sectors more useful information on variability
and trends with a view to addressing the many multi-hazard challenges facing the country.
The synoptic features indicated dominance of the subtropical high pressure systems at the
beginning of the year, leading to the raising of dust particles at the surface in the Sahara
Desert and subsequent transportation and reduction of horizontal visibility across the
country. The southwesterly winds gained momentum at the coast and progressively moved
inland at the end of first quarter of the year. The monsoon trough remained very active
across the country till the end of the third quarter, and this brought about enhanced rainfall
and thunderstorms, flash flooding and the associated impacts.
The seasonal and meridional oscillations of the Inter-Tropical Discontinuity (ITD) attained a
peak position of about latitude 18.8oN in August. In addition, the dynamics of the
atmosphere showed unusual surging and pulsation of the ITD, such that severe storms were
experienced over the coast as early as February in 2012, particularly over Lagos. Further
scientific studies are presently being undertaken to understand the causative factors.
Rainfall amounts were normal to above normal with high intensity rainfall duration in some
occasions leading to flooding during the months of July, August and September. It is
4
important to note that for the first time since 2008, the northeast had rainfall more than
normal values in more than ten consecutive years. Widespread flooding peaked between
September and mid-October across the country and was particularly severe in the
northcentral and coastal states. Nigeria experienced the worst flooding in 2012 for more
than a century.
The hot season in 2012 was warmer than normal in the north but normal in the south
except over the extreme southeast which was colder than normal. The comfort index
anomaly showed greater than normal discomfort during the hot season in the north but
other regions were comfortable over the same period. The August break of 2012 over
southwest Nigeria lasted for about two weeks at Ibadan and five weeks at Ikeja. The
phenomena lasted till the first week in September.
Extreme weather and climate events in 2012 led to significant socioeconomic impacts.
Strong winds in the magnitude of 60-70knots were experienced in the south and the north
for the months of February and June respectively. Daily maximum temperatures of 40.0 oC
and higher were experienced in the northern part of the country and in some places for
sixty days, although the days were not consecutive. High impact daily rainfalls of 100.0mm
and higher values were recorded in the year between May and August.
Preliminary analyses in the agricultural sector suggest that out of the major food crops
(Yam, Cassava, Maize, Sorghum and Rice) being produced in the country, yam would be the
mostly affected, followed by rice and cassava. There were outbreaks of cholera in some
states due to food and water contamination from floods. Mostly affected states by the
flooding were Kogi, Adamawa, Delta and Bayelsa States. Storms destroyed infrastructures
leading to disruption of socioeconomic activities.
This Bulletin has provided scientific information and data for further research, source of
materials for experts in the socioeconomic sectors to further appraise the year 2012 in
multidisciplinary analyses of the climate events. In all, the bulletin is highly recommended
for those who are affected by the Nigerian climate in one way or the other. It is indeed a
valuable document as reference material for libraries.
5
2.0
EVIDENCE OF CLIMATE CHANGE
The climate of Nigeria has shown considerable signals of a changing climate through the
careful study of meteorological data. Analysis of long term trends of meteorological
parameters such as rainfall, in terms of onset and cessation of the rainy season, hail
frequency and average maximum temperature during the hot season (February - April) lend
support to this deduction.
2.1
ONSET AND CESSATION OF WET SEASON
The onset of the rainy (wet) season between 1941 and 1970 was mostly from “early to
normal” (Fig. 1a). Isolated places around Sokoto, Maiduguri, Owerri, Port Harcourt and
Calabar had late onset of the rainy season. However, increasingly late onset of the rainy
season characterised later years such that by 1971-2000 a vast portion of the country now
experience late onset of the rains (Fig. 1b).
14.00
14.00
SOK
KAT
SOK
NGU
BRK
GUS
DAM
POT
MAI
BAU
GOM
JOS
10.00
MIN
JEB
YOL
ABU
JLG
LAF
12.0
IBI
LOK
OSB
IBA
ABE
IKE
BID
ILO
AKU
OND
OTU
IJB
BEN
6.00
10.0
MKD
ONT
WAR
YEN
ENU ABK
8.0
OGJ
IKM
UMU
OWE
PHC
JEB
SHK
YOL
ABU
LOK
JLG
ONT
WAR
YEN
ENU ABK
8.00
10.00
12.00
14.0
12.0
IKM
PHC
10.0
Late Onset of Rains
UMU
OWE
CAL
8.0
6.0
4.0
2.0
4.00
Normal Onset of Rains
-6.0
6.00
16.0
OGJ
-2.0
-4.0
4.00
18.0
OTU
IJB
6.00
20.0
MKD
AKU
OND
BEN
Early Onset of Rains
2.00
GOM
IBI
0.0
4.00
BAU
LAF
OSB
IBA
4.0
Normal Onset of Rains
BID
ILO
ISY
IKE
2.0
MAI
MIN
ABE
Late Onset of Rains
DAM
POT
JOS
10.00
6.0
CAL
KAD
KON
8.00
DUT
ZAR
YEL
KAD
KON
ISY
NGU
KAN
12.00
Latitude (degrees N)
Latitude (degrees N)
DUT
ZAR
YEL
8.00
GUS
KAN
12.00
SHK
KAT
BRK
0.0
-2.0
14.00
2.00
Longitude (degrees E)
4.00
6.00
8.00
10.00
12.00
14.00
Longitude (degrees E)
1a: The dates
Distributionanomaly:
of Anomaly of (1941-1970)
minus (1911-1940)
Fig. 1a: Fig.
Onset
1941-1970
Mean Onset Dates of Dates of Rainy Season in Nigeria
1b: The Distribution
Anomaly of (1971-2000)
minus (1911-1940)
Fig. 1b:Fig.Onset
dates ofanomaly:
1971-2000
Mean Onset Dates of Dates of Rainy Season in Nigeria
6
Similarly, the cessation of the rainy season in the country transformed from being generally
“normal” between 1941 and 1970 (Fig. 2a) to “early cessation” during the 1971 – 2000
period (Fig. 2b).
14.00
14.00
SOK
KAT
SOK
NGU
GUS
KAN
12.00
DAM
POT
MAI
GOM
MIN
JEB
YOL
ABU
JLG
LAF
IBI
LOK
OSB
IBA
ABE
IKE
BID
ILO
AKU
OND
OTU
IJB
BEN
6.00
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
-0.5
-1.0
-1.5
-2.0
-2.5
-3.0
-3.5
-4.0
-4.5
-5.0
-5.5
-6.0
-6.5
-7.0
MKD
ONT
WAR
YEN
ENU ABK
OGJ
IKM
Normal Cessation of Rains
UMU
OWE
PHC
CAL
Early Cessation of Rains
4.00
KAD
KON
DAM
POT
MAI
BAU
GOM
JOS
10.00
MIN
JEB
SHK
8.00
DUT
ZAR
YEL
BAU
JOS
10.00
ISY
NGU
KAN
12.00
Latitude (degrees N)
Latitude (degrees N)
DUT
KAD
KON
8.00
GUS
ZAR
YEL
SHK
KAT
BRK
BRK
ISY
YOL
ABU
JLG
LAF
IBI
LOK
OSB
IBA
ABE
IKE
BID
ILO
AKU
OND
-3.0
OTU
IJB
BEN
6.00
-2.0
MKD
ONT
WAR
YEN
ENU ABK
-4.0
OGJ
-5.0
-6.0
IKM
PHC
-7.0
-8.0
UMU
OWE
CAL
Normal Cessation of Rains
-9.0
-10.0
-11.0
-12.0
Early Cessation of Rains
4.00
-13.0
-14.0
-15.0
2.00
4.00
6.00
8.00
10.00
12.00
2.00
14.00
4.00
6.00
8.00
10.00
12.00
14.00
Longitude (degrees E)
Longitude (degrees E)
Fig. 2a: The Distribution
of Anomaly
of (1941-1970)
minus (1911-1940)
Fig. 2a: Cessation
dates
anomaly:
1941-1970
Mean Cessation Dates of Dates of Rainy Season in Nigeria
2b: The Distribution
of Anomaly
of (1971-2000)
minus (1911-1940)
Fig. 2b:Fig.
Cessation
dates
anomaly:
1971-2000
Mean Cessation Dates of Dates of Rainy Season in Nigeria
The period of the rainy season in the country has been reduced from 1941 when the onset
and cessation were generally normal to 1971 when signals of late onset and early cessation
of the rainy season set in. Since then, the length of the rainy season has remained shrinking
while annual total rainfall is about the same, thereby giving rise to high impact rainfall,
resulting in flash floods.
7
2.2
HAIL FREQUENCY
The occurrence of hail during the rainy season in the country has steadily diminished and
virtually disappeared by the turn of the century.
Jos, which was one of the places in Nigeria where hail occurrence was a common
characteristic of the rainy during the mid 20th century, no longer experience this
phenomenon on an annual basis from the end of the century. The time series of decadal hail
occurrence at Jos (Fig. 3) shows a very high frequency of occurrence between 1942 and
1951, but rapidly reduced with time and completely disappeared by 1992.
The same trend of hail occurrence has been observed over the country as a whole, which
goes to further strengthen the evidence of general warming across the country.
45
40
35
FREQUENCY
30
25
20
15
10
5
0
1942-1951
1952-1961
1962-1971
1972-1981
1982-1991
Fig. 3: Jos Hail Frequency 1942 - 2010
8
1992-2001
2002-2010
2.3
MEAN TEMPERATURE
Temperatures across the country show an increasing trend from mid 20th century to date.
The mean temperature anomaly (Fig. 4a) shows clearly the prevalence of warming in the
country. Temperatures have increased from 0.2 – 0.5C in the high ground areas of Jos,
Yelwa and Ilorin in the north and Shaki, Iseyin and Ondo in the southwest to 0.9 - 1.9C over
the rest parts of the country.
14
12
10
Key
2
8
1.5
6
0.5
4
0
2
2
4
6
8
10
12
14
Fig. 4a: Mean Temperature Anomaly: 1942 - 2000
The area averaged maximum temperature during the hot season also show increasing
trends in both the south and in the north (Figs 4b & 4c). In addition, the trend analyses
reveal a higher rate of temperature increase per decade in the south (2.5 C) than in the
north (1.4C).
9
3.0
SYNOPTIC FEATURES
3.1
SURFACE PRESSURE AND WINDS
The Climate of Nigeria is basically tropical in the south and savannah in the north. The
seasonal north-south movement of the dry north easterly winds from the Sahara Desert and
the moist south westerly winds from the Atlantic Ocean defines this climate.
At the surface, pressure values over North Africa, fluctuated between 1021 – 1026 hPa
during the first quarter. The north easterly winds periodically raised dust particles into the
atmosphere over the Sahara Desert, following the occasional strengthening of the surface
high pressure in the region. The raised dust particles were progressively transported
southwards across the country and horizontally visibility was occasional reduced to less than
1000m particularly in the north. At the lower levels (up to 1,500m), moderate north easterly
winds dominated the flow pattern. The speed of the low level winds fluctuated between 12
– 28 knots (6 – 14m/s).
The low-level wind convergences which appeared occasionally along the coast during the
first quarter of the year became well established and active in the second quarter, giving
rise to early rainfall in the south. This development was aided by the weakening of the
Saharan High pressure and strengthening of the St Helena High pressure which resulted in
the northward movement of moist southwesterly winds. The monsoon trough remained
very active across the country till the end of the third quarter, brought about enhanced
rainfall and thunderstorms, flooding and record socio-economic implications. At the height
of 1,500m, the moist southwesterly winds penetrated inlands to reach an average position
of latitude 13.8oN.
During the fourth quarter, the Saharan High pressure over North Africa intensified again,
leading to the cessation of the rainy season and beginning of the dry season in the country.
This led to the dominance of dry northly winds over the wind regime, raising of dust
particles at the Sahara Desert and the subsequent southward transport of the dust plumes
into the northern parts of the country.
10
3.2
INTER-TROPICAL DISCONTINUITY (ITD)
Variations in the location of the Inter-Tropical Discontinuity (ITD) influence the rainfall over
Nigeria. Dry weather conditions prevail to the north of its position while convection and
rainfall take place to the south.
The ITD was located at a mean position of latitude 7.2 °N in January 2012 (Fig. 5). It pushed
northward rapidly from 20th January to 28th February to reach latitude 11.1°N which was far
higher than normal and out of phase with the normal. The ITD slowed down thereafter and
remained lower than normal till 10th May but maintained a nearly normal position till 30 th
September. The peak position of the ITD in 2012 was latitude 18.8°N reached in the second
dekad of August. From October, there was a rapid southward movement of its position
reaching latitude 7.6 °N in December.
21.0
19.0
17.0
15.0
LAT (deg. N)
13.0
11.0
9.0
7.0
5.0
10
20-Jan
30
10
20-Feb
30
10
20-Mar
30
10
20-Apr
30
10
20-May
30
10
20-Jun
30
10
20-Jul
30
10
20-Aug
30
10
20-Sep
30
10
20-Oct
30
10
20-Nov
30
10
20-Dec
30
3.0
2012
NORMAL
Fig. 5: Dekad positions of ITD in 2012
11
During the months of February and March, the positions of the ITD were above normal (Fig.
6). This accounted for the early onset of rainfall in the south in February. However, it was
below normal throughout the rest of the year.
6.0
5.0
LATITUDE (DegC)
4.0
3.0
2.0
1.0
0.0
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
-1.0
-2.0
Fig: 6. 2012 ITD position Anomaly.
3.3
SEA SURFACE TEMPERATURE ANOMALIES (SSTAs)
AND GLOBAL CIRCULATIONS
The La Niña condition which prevailed during the later months of 2011 continued in early
2012 with below average sea surface temperatures (SSTs). However, the SST in the Niño-3.4
region which was near –1.0°C began to warm and by the end of February, the La Niña
weakened to near –0.5°C below average SSTs (Fig. 7). This trend continued in March, April
and May, with large scale atmospheric circulation anomalies and the Southern Oscillation
Index (SOI) indicative of a transition from La Niña to ENSO-neutral condition.
ENSO-neutral condition started in June in both the oceanic and atmospheric anomalies with
increased tendency for El Nino but by positive equatorial Pacific sea surface temperature
(SST) anomalies have exceeded +0.5°C by August, although still within the limits of ENSOneutral condition. The remaining months of the year clearly indicated ENSO-neutral
conditions despite above average SSTs.
12
1
Oceanic Nino Index (ONI) for 2012
Temperature (deg.C)
0.5
0
Jan
Feb Mar
Apr May Jun
Jul
Aug
Sep
Oct
Nov Dec
-0.5
-1
Fig. 7: Oceanic Nino Index (ONI) over Nino 3.4 region
The second half of 2012 clearly showed warm-neutral ENSO condition. Upper and lowerlevel zonal winds were near average, and convection was slightly suppressed over most of
the tropical atmosphere.
The outlook for 2013 is that the warm-neutral ENSO condition is likely to last till Northern
Hemisphere summer. However, it will be in the ENSO-neutral range even though the
average dynamical model forecast is warmer than the statistical model mean.
13
4.0
TEMPERATURES
4.1
HOT SEASON MAXIMUM TEMPERATURES
Maximum temperatures during the hot season (February and March) in the south and
(March and April) in the north, showed that temperature ranged between 30.1 – 40.0°C
(Fig. 8). The maximum temperature gradually increased inland from the coastal areas, with
the exception of Jos and its environs. The southeast coastal areas had mean maximum
temperatures of 30.0 – 33.0°C, while the coast of the southwest and the inland cities of the
south recorded maximum temperatures between 33.0 – 36.0°C. Maximum temperatures
over the central areas and the north central parts ranged between 36.0° -38.0°C during the
period except for Jos and its environs which had mean maximum temperature ranging
between 30° -36°C. Jos recorded the lowest maximum temperature of 30.1°C. Elsewhere in
the north, maximum temperatures were between 38.0° - 40.0°C.
14
12
Lat (N)
10
40
8
38
6
36
33
4
30
2
2
4
6
8
Long (E)
10
12
Fig. 8: 2012 Hot Season Maximum Temperature
14
14
4.2
HOT SEASON MAXIMUM TEMPERATURE ANOMALY
The hot season in 2012 was warmer than normal in the northern parts of the country with
maximum temperature departures ranging from 0.5 - 2.5°C (Fig.9). Normal temperature
conditions were experienced at the southern and central parts of the country in the year,
except for Makurdi and Bida where maximum temperatures were 0.5-1.5°C higher than
normal maximum temperatures. On the other hand, Calabar, Uyo and Eket, in the extreme
southeast coast, recorded maximum temperatures lower than normal by 0.5 - 2.5°C.
14
12
10
Warmer than
Normal
2.5
8
6
1.5
0.5
Normal
-0.5
Colder than
Normal
Lat (N)
Key
4
-1.5
-2.5
2
2
4
6
8
10
12
14
Long (E)
Fig. 9: 2012 Hot Season Maximum Temperature Anomaly
15
4.3
COLD SEASON MINIMUM TEMPERATURES
Monthly minimum temperature across the country during the cold season (January) showed
that low minimum temperatures, between 10.0 - 14.0°C, were recorded in the northeast,
Kano, Katsina and the areas around Jos in the central region (Fig. 10). The remaining parts of
the north experienced season minimum temperatures between 14.0 -18.0°C while cold
season minimum temperatures ranged between 18.0 – 22.0°C over the northcentral and the
south except at the coastal cities which experienced the highest temperatures range of 22.0
– 24.0°C. The highest cold season minimum temperature in the south (24.1°C) was recorded
at Eket.
Lower minimum temperatures were recorded in the extreme northeast and Jos in the cold
season of 2011 than over the same area in 2012.
14
12
Lat (N)
10
8
Key
24
22
6
18
4
14
10
2
2
4
6
8
10
12
Long (E)
Fig. 10: 2012 Cold Season Minimum Temperature
16
14
4.4
COLD SEASON MINIMUM TEMPERATURE ANOMALY
Cold season minimum temperatures in 2012 were generally normal across the country
when compared with 1971 – 2000 average values (Fig. 11).
Colder than normal temperatures (0.5 - 3.0°C) were recorded during the season in places
such as Sokoto, Katsina, Kano, Jos and Ilorin in the north, as well as over Iseyin, Oshogbo,
Akure, Benin and Enugu in the south. However, Owerri in the southeast recorded the lowest
cold season minimum temperature anomaly of -3.2°C.
Warmer than normal temperatures (0.5° -2°C) were experienced over Ibi, Bida and Makurdi
in the central states, and over Eket in the southeast coast. Minimum temperatures were
normal in other parts of the country during the cold season.
Comparatively, 2012 cold season was similar to 2011 but colder than 2010.
14
12
Warmer than
Normal
Lat (N)
10
8
Key
2
0.5
Normal
6
Colder than
Normal
-0.5
4
-2
-3.5
2
2
4
6
8
10
12
14
Long (E)
Fig. 11: 2012 Cold Season Minimum Temperature Anomaly
17
4.5
ANNUAL MEAN TEMPERATURE ANOMALY
Mean temperature departure analysis for 2012 showed that most places in the country
experienced normal mean temperatures compared to 1971-2000 long term values (Fig. 12).
Owerri in the southeast and Makurdi in the northcentral were 1.1°C colder than normal. On
the other hand, Bauchi and Gusau in the north were 1.0°C and 1.1°C respectively warmer
than normal. Slightly warmer than long term temperatures (0.6°C) were however
experienced in places such as Maiduguri, Yola and Yelwa in the north, and Warri and Ondo
in the south.
On the average, mean temperature anomalies in 2012 were lower than 2010 and 2009 but
the spatial pattern was identical to 2011 mean temperature anomalies.
14
12
Key
Warmer than Normal
8
1.5
1
0.5
6
Normal
4
Colder than Normal
Lat (N)
10
-0.5
-1
-1.5
2
2
4
6
8
10
Long (E)
Fig. 12: 2012 Mean Temperature Anomaly
18
12
14
5.0
SOLAR RADIATION
The northern states of Katsina, Kano, Jigawa, Gombe, Yobe and Borno states received the
greatest amount of incident solar radiation ranging from 26.0 – 28.0 Wm-2 day-1 during the
hot season in the country (Fig. 13). The incident solar radiation was between 24.0 26.0Wm-2day-1 over Sokoto, Kebbi, Zamfara, Kaduna, Bauchi, Plateau, Taraba and Adamawa
states, while states in the central region received 22.0 - 24.0 Wm-2 day-1 of solar radiation.
The inland states of the south and the coastal areas recorded 20.0 - 22.0Wm-2day-1 and from
18.0 - 20.0 Wm-2 day-1 of incident solar radiation respectively.
Lowest incident solar radiation of 18.0Wm-2 day-1 was recorded over Eket and Calabar while
Katsina had the highest value of 27.3 Wm-2 day-1.
14
12
10
KEY
Lat (N)
28
8
26
24
6
22
4
20
18
2
2
4
6
8
10
12
Long (E)
Fig. 13: Incident Solar Radiation in February 2012
19
14
6.0
RAINFALL
6.1
CUMULATIVE ANNUAL RAINFALL
Cumulative rainfall in the year was between 1000.0 – 2000.0mm over a vast portion of the
country, stretching from Nguru in the extreme north to the central states and most parts of
the south (Fig. 14).
Maiduguri, Nguru and Yola in the northeast, Sokoto and Yelwa in northwest, and Shaki in
the southwest recorded rainfall amounts ranging from 500.0 -1000.0mm. Rainfall values of
3000.0 - 4000.0mm were recorded over the extreme southeast portion of the country. The
highest rainfall of 4627.2mm occurred at Uyo, while Sokoto recorded the least rainfall
amount of 613.4mm.
Generally rainfall amount in 2012 was more than 2011 and 2010.
14
12
Lat (N)
10
Key
8
5000
4000
6
3000
2000
4
1000
500
2
2
4
6
8
10
12
Long (E)
Fig. 14: 2012 Cumulative Annual Rainfall
20
14
6.2
RAINFALL ANOMALY
The rainfall anomaly showed that wetter than normal rainfall conditions were experienced
over most parts of the country in the year; especially over the eastern halve (Fig. 15a). For
the first time in recent years, the extreme northeast corner of the country had wetter than
normal rainfall.
The other parts of the country located over the western sector recorded normal rainfall
except for isolated cases of drier than normal rainfall experienced over Gusau in the
extreme northwest and Shaki in the inland of the southwest.
14
12
10
Key
Wetter than
Normal
8
6
110
Normal
90
Drier than
Normal
Lat (N)
200
4
0
2
2
4
6
8
10
12
Long (E)
Fig. 15a: 2012 Rainfall Anomaly
21
14
Further analysis of the 2012 rainfall shows that it was much higher than the 2011 values
over a greater portion of the country (Fig.15b). The northeast and areas around Minna and
Abuja recorded more than 160% 0f 2011 rainfall. However, rainfall in the year was less than
the preceding years’ over Yelwa, Ilorin, and Southwest except for Abeokuta, Owerri, and
parts of Edo and Delta states.
14
KAT
SOK
GUS
NGU
KAN
12
POT
ZAR
YEL
KAD
BAU
BID
10
JOS
MIN
YOL
8
ABE
IKE
180
ILO
SHA
ISE
IBI
LOK
IBA
IJE
6
MAK
AKU
OND
ENU
BEN
WAR
Key
Higher
Lat (N)
ABU
160
140
OWE
POR
120
UYO
CAL
Lower
100
4
2
2
4
6
8
10
12
Long (E)
Fig. 15b: 2012 Rainfall in percentage of 2011 Rainfall
22
80
60
14
6.3
AUGUST RAINFALL ANOMALY
The climatology of August rainfall in the country exhibits rainfall maxima in the north due to
the northernmost influence of moisture from the South Atlantic Ocean while the south, and
in particular the southwest, experiences rainfall minima in the month.
The 2012 August rainfall anomaly (Fig. 16) depicts a drier than normal rainfall condition in
the western half of the country, stretching from Sokoto and Gusau in the far north to Bida
and Ilorin in the central region. Also, Jos, Ibi and Makurdi, the southwest and the western
half of the Niger delta recorded drier than normal August rainfall.
Wetter than normal rainfall in the month occurred in the eastern half of the north and the
southeast while other places in the country experienced normal August rainfall. Coastal
areas in the southeast (Eket, Calabar, Uyo, Ogoja) and Kano, Nguru and Potiskum in the
north had 350.0 – 500.00 mm and 123.0 – 333.0mm surplus rainfall in the month
respectively.
14
12
10
Key
Wetter than
Normal
8
6
200
110
Normal
4
Drier than
Normal
Lat (N)
250
2
2
4
6
8
10
12
Long (E)
Fig. 16: 2012 August Rainfall Anomaly (%)
23
14
90
10
6.4
RAINFALL MONTHS ANOMALY
Rainfall month, for purposes of this bulletin, is regarded as the month in which the total
amount of rainfall is equal to or greater than 50.0mm. In the year under review, a
considerable portion of the country had normal rainfall months (Fig. 17). Places in the
extreme north, Jos and Zaria in the central region, and Ijebu-Ode, Enugu, Benin, Eket and
Calabar in the southern part of the country had 1 -2 months of rainfall higher than normal.
On the other hand, rainfall months in other parts of the country were 1 -2 months shorter
than normal. These places include Bauchi, Bida, Minna and Ilorin in the north, and Shaki,
Iseyin, Lagos and Ikom in the south.
The generally normal rainfall months in the year coupled with the good rainfall, especially
over the eastern half of the country, was partly responsible for the extensive flooding
experienced in the year.
14
12
8
Wetter than
Normal
Lat (N)
10
6
Key
2
2
1
1
0.5
Drier than
Normal
Normal
4
-1
-0.5
-1
-2
-2
2
2
4
6
8
10
12
Long (E)
Fig. 17: 2012 Rainfall months’ Anomaly
24
14
6.5
LITTLE DRY SEASON (LDS)
Little Dry Season (LDS) is a period of significantly reduced rainfall in terms of amount and
frequency during the rainy season in the southern part of the country which normally occurs
between the last week in July and the first two weeks in August. In the year under review,
the LDS signal was first felt over the inland of the southwest (Akure, Ibadan and Ijebu-Ode)
in the 3rd of July and then intensified to influence the amount of rainfall in other parts of the
region. The season lasted till the first week in September.
In 2012, the Little Dry Season (LDS) lasted from two weeks (Ibadan) to five weeks (Ikeja)
with the exception of Iseyin where the season lasted for about a week. Following the
pattern of the previous years, the Little Dry Season lasted longer in Lagos (37 days) than in
any other place in the southwest. A summary of the intensity of the Little Dry Season in the
southwest during the past four consecutive years (2009 – 2012) is shown in Table 1 below.
S/No
City
Period (2012)
August 1- 17
2012
Duration
(Days)
17
2011
Duration
(Days)
22
2010
Duration
(Days)
6
2009
Duration
(Days)
36
1
Abeokuta
2
Akure
July 17 – August 17
32
12
0
17
3
Ikeja
August 1 – Sept 6
37
23
20
46
4
Ijebu-Ode
July 24 – August 9
17
8
7
17
5
Iseyin
August 9 – 17
8
11
10
16
6
Ondo
August 1 – 21
21
7
10
15
7
Osogbo
August 1 – 16
16
11
18
30
8
Shaki
August 4 – 16
13
7
9
0
9
Ibadan
July 16 – August 3
19
0
10
25
Table 1: Little Dry Season in the Southwest: 2009 - 2012
25
The LDS in 2012 was more pronounced than in any of the three preceding years in the
southwest except at Abeokuta and Iseyin where the season lasted for a shorter period
compared with 2011 (Fig. 18).
40
35
30
Days
25
20
15
10
5
2011
2010
Ibadan
Shaki
Oshogbo
2012
Ondo
Iseyin
I-Ode
Ikeja
Abeo
Akure
0
Fig. 18: Comparison of Little Dry Season severity: 2012, 2011 and 2010
The monthly distribution of rainfall in the region depicts the pronounced impact of the 2012
LDS in the southwest (Fig. 19). The rainfall in August 2012 was below the 1971-2000 average
August rainfall in the region.
350.0
300.0
Rainfall (mm)
250.0
200.0
150.0
100.0
50.0
2012
Normal
Fig. 19: Monthly Rainfall in the Southwest (area averaged)
26
DEC
NOV
OCT
SEP
AUG
JUL
JUN
MAY
APR
MAR
FEB
JAN
0.0
7.0
DUST HAZE
The first major dust haze spell of the year occurred from January 1st – 21st (Table 2). Surface
horizontal visibility was reduced to less than 1000m in most parts of the country during the
period.
Thick dust haze was experienced between 2nd – 7th February in the northeastern part of the
country. It became widespread during February 11 – 18th when places such as Maiduguri,
Nguru and Ikeja reported horizontal visibilities of 300m, 600m, and 800m respectively. The
extreme northern part of the country was again engulfed in another dust haze spell
between 25 – 29th which reduced horizontal visibility to between 700m (Sokoto) and 300m
(Maiduguri).
Generally, hazy weather conditions prevailed during the second and fourth weeks of March.
But thick dust haze was experienced between 2nd and 8th of March over Maiduguri, Gombe,
Yola, Kano and Sokoto. Kano had the poorest horizontal visibility of 500m. Another dust
haze spell was experienced between 16th – 21st when the horizontal visibility was reduced to
200 – 800m over Maiduguri, Yola, Gombe and the central states.
Dry weather conditions returned after the rainy season (April and October), bringing dust
particles into the country. One dust spell was recorded from November 23 rd – 25th which
reduced horizontal visibility to 800m in the extreme north. The second dust haze spell of the
month was recorded from December 14th – 19th which reduced horizontal visibility to
between 800 – 1500m in the extreme north and central region of the country.
27
Date
Number of spells
January 1st – 21st
1
February 2nd – 7th
February 11th – 18th
February 25th – 29th
3
Effects
Visibility reduced to 200 – 800m in the north
and 600 – 1000m in the south. Deterioration in
visibility due to dust haze was wide spread.
Visibility reduced to 600 – 1000m over the
northern fringes of the country with
pronounced reduction in Maiduguri and
environs.
March 3rd – 8th
March 16th – 21st
2
Visibility reduced to 200 – 800m over Yola,
Maiduguri and Gombe.
November 23rd – 25th
1
Visibility reduced to 800m over Kano.
December 14th – 19th
1
Visibility reduced to 800 – 1500m over Kano and
Yola.
Table 2: Summary of Dust Haze Spells and Effects
28
8.0
EXTREME METEOROLOGICAL PARAMETERS
8.1
WIND SPEED
Destructive winds with speeds of the order of 35knots and higher (Squall) are usually
experienced during the beginning and cessation of the rainy season in the country. In the
current year, these winds (60-70knots) were experienced between February in the south
and June in the north (Table 3).
S/N
STATION
HIGHEST VALUE(kts)
MONTH
1.
Ikeja
60
February
2.
Ibadan
60
May
3.
Jos
70
May
4.
Abuja
60
May
5
Gombe
60
June
Table 3: Daily wind speed of 40knots and higher in 2012
8.2
TEMPERATURES
Daily maximum temperatures of 40.0oC and higher were experienced in the northern part
of the country, which lasted for upwards of ten days except for Gombe, Minna and Makurdi
(Table 4). As in previous years, the extreme north experienced highest daily maximum
temperatures of 42.0 - 44.7oC between February and May 2012 and over a period of forty to
sixty (non-consecutive) days. Yola had the highest frequency of sixty days while the least
frequency of occurrence (4 days) was at Makurdi.
S/N
1
Station
Maiduguri
Value (oC )
44.7
Period
February - May
Frequency (Days)
53
2
3
4
Nguru
Sokoto
Yelwa
43.6
43.6
43.5
March - May
February - May
February - May
57
51
41
5
6
7
8
9
10
11
12
13
14
15
16
Potiskum
Gusau
Kano
Yola
Katsina
Ibi
Bauchi
Gombe
Lafia
Minna
Makurdi
Bida
42.4
42.2
42.1
42.1
42.0
41.2
41.0
41.0
40.8
40.8
40.3
40.0
March - May
February - May
March - May
February - May
April - May
March
March - May
April
March
March
March
March
48
30
38
60
34
10
29
9
16
7
4
10
Table 4: High Daily Temperatures in 2012
29
8.3
RAINFALL
High impact daily rainfalls of 100.0mm and higher values were recorded in the year between
May and August (Table 5). Ikeja, Oshodi and Lagos Island recorded the highest 24-hour
rainfall amounts of 216.3mm, 225.8mm, and 169.8mm respectively in June while Gombe,
Kano and Zaria in the north had 120.4mm, 143.0mm and 158.4mm of rainfall respectively in
August. The daily rainfall in September 2012 did not exceed 99.0mm unlike in 2011 where
cities in both the north and south had this magnitude of rainfall in the month.
S/N
Station
Rainfall (mm/day)
Month
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Port Harcourt
Calabar
Abeokuta
Eket
Ijebu- Ode
Ikeja
Ogoja
Oshogbo
Uyo
Uyo
Oshodi
Lagos Island
Lagos Marine
Calabar
Ijebu-Ode
Maiduguri
Owerri
Uyo
Warri
Calabar
Gombe
Kano
Zaria
100.2
100.7
134.2
121.8
110.1
216.3
101.3
117.9
105.6
158.4
225.8
169.8
115.3
132.8
132.5
107.3
128.8
111.7
113.6
123.8
120.4
143.0
158.4
May
June
June
June
June
June
June
June
June
June
June
June
June
July
July
July
July
July
July
August
August
August
August
Table 5:
Daily rainfall of 100.0mm and higher in 2012
30
9.0 SOCI O-ECONOMIC IMPACTS
The socio – economic impact of the 2012 climate under review had significant effect on
agriculture, hydrology, construction, education and health sectors, as discussed below.
9.1
AGRICULTURE
Agriculture is a sector that is highly dependent on weather due to the rainfed agricultural
practice in the country.
Excessive rainfall from July to October and the release of water from several dams, such as
the Kainji and Jebba hydroelectric power Dams in Nigeria and Lagdo Dam in Cameroun,
resulted in high water levels in rivers and ponds and widespread flooding in 33 states in the
Country. According to FEWSNET, these have damaged about 1.9 million hectares of
cropland and are estimated to have reduced production levels for the current season mainly
along the floodplains by 22.4% (rice), 14.6% (maize), 11.2% (soybeans), 9.3% (cassava) and
6.3% (cowpea).
Due to the likely impact of the flooding, there are widespread fears that the 2012
production levels would be lower than what was previously forecasted at the beginning of
the season. In one of the synopsis of the flood impact on agriculture, it was indicated that
out of the major food crops (Yam, Cassava, Maize, Sorghum, Rice) being produced in the
country, yam would be the mostly affected, followed by rice and cassava (Fig. 20).
600,000
500,000
Ha
400,000
300,000
200,000
100,000
0
Rice
Sorghum
Cassava
Fig. 20: Estimated Crop Loss (ha)
31
Yams
Maize
Random sample checks on the flood impacts on agriculture across the county showed that
over 1,600 farm lands were affected by flood in Gombe State, no fewer than 400,000
farmlands were destroyed in Jigawa State by the flood, 800 hectares of yam and plantain
farms in three communities in Oshimili South and Ndokwa East Local Government of Delta
State were also destroyed by flood waters and over 350 hectares of cassava farmland were
washed away in Edo State by the flood.
On the fisheries subsector, estimated losses due to the flood impact among the front line
states is put at close to two hundred and thirty million naira (N230,000.00). The fourteen
states where fisheries were most impacted and the respective losses are shown in Fig. 21.
Kebbi state suffered the highest estimated loss amounting to over seventy one million naira
(N71.397m), followed by Delta state (N48.885m) and Bayelsa state (46.076m).
80,000,000
70,000,000
Naira
60,000,000
50,000,000
40,000,000
30,000,000
20,000,000
10,000,000
Fig. 21: Estimated Fisheries Loss
32
Taraba
Plateau
Niger
Kwara
Kogi
Kebbi
Jigawa
Imo
Edo
Delta
Benue
Bayelsa
Anambra
Adamawa
0
9.2
HEALTH
Primary health facilities in several states were damaged by the flooding thereby limiting
access to, and stretched basic health services, especially in Bayelsa and Delta States. The
situation was compounded by the general inadequate medical staff, supplies and
commodities in places where some medical services were provided. Sexual and
reproductive health care including emergency obstetric and newborn care, access to
management of childhood illnesses including treatment of acute malnutrition were lacking.
Also, referral services for life threatening conditions were poorly organized or non-existent.
Lack of clean drinking water due to the flooding occasioned by the heavy rains and the
release of water from several dams resulted in cholera outbreak in Nigeria. The Federal
Ministry of Health had reported that many people in the impacted communities were
affected by the disease which resulted in the death of a sizeable number of people.
Other prevalent health problems reported include diarrhoea, malaria and typhoid
particularly in the coastal states of Delta, Rivers, Bayelsa and Anambra state, and along the
Niger and Benue Rivers (FEWSNET 2012).
These diseases increased hospital admissions, reduced labour availability and exposed
affected populations to increased healthcare related expenditures.
33
9.3
EDUCATION
In the education sector, the flood disrupted academic activities in most of the schools in the
impacted states as secondary and primary schools (in non-affected areas) served as Camps
to accommodate the Internally Displaced Persons (IDPs) from the affected communities.
Some state governments (e.g. Bayelsa, Adamawa) ordered the closure of schools in their
states due to the rising water levels (Fig. 22) and the danger it posed to the students and
residents (FEED 9th October). Report also has it that the Niger Delta University (NDU),
Amassoma in Bayelsa State was also submerged by flood. Scheduled national examinations
such as that of the National Examination Council (NECO) had to be rescheduled following
the downpour in Lagos from Wednesday 27th June to the morning of Thursday 28th June.
Fig. 22a: Aerial view of a submerged school in Bayelsa State
Fig. 12b: Osagbe College, Udaba-Ekphei in Edo State submerged
34
9.4
HYDROLOGY
The wet season started early in February/March in the south and in early May/June in the
north. Widespread flooding peaked between September and mid-October across the
country and was particularly severe in the northcentral and coastal states. Nigeria
experienced the worst flooding in more than 100 years. The National Inland Waterways
Authority (NIWA) indicated that the 2012 flooding was the second highest in the country;
the first and highest occurred in 1932.
The water level of Niger River in Lokoja rose from about 6.5m normal level to peak at 12.8m
on 29th September due to the heavy rains and release of water from the dams but fell to
8.8m on 1st November (SITREP NIGERIA Floods 2012) as the flood water receded. In
Cameroon, on the 24th August, torrential rainfall caused a dramatic rise in the water level of
the Lagdo Dam and the spillway was overflowed. Excess water was released from the dam
to avoid its breakage. The opening of the dam led to flooding along River Benue in Nigeria.
This flooding displaced over 2.2 million people, 363 people reported dead (NEMA), damaged
several thousand hectares of cropland and destroyed houses and personal properties. Out
of the 36 states of the country, 33 were affected, including 14 that were considered to be
severely impacted. A total of 256 Local Government areas (LGAs) and 3,870 communities
were affected. Kogi state recorded the highest number of affected population (1.35 million)
followed by Adamawa (1.11 million) and Delta (785,000) (SITREP NIGERIA Floods 2012).
Fig. 23: Moderate Resolution Imaging Spectro-radiometer (MODIS) on NASA's Aqua
satellite captured the increased volume of Niger and Benue Rivers on October 11, 2012.
35
9.5
AVIATION
In the months of January, February and March, there were outbreaks of dust haze which
reduced horizontal surface visibility to between 200 - 900m in the north and parts of the
south. In January and February, Ikeja, Calabar, Port Harcourt, Oshogbo, Warri and Ado Ekiti
witnessed reduction in visibility to about 100 - 800m due to early morning fog. These
weather features disrupted flight activities at the airports as flights were delayed,
rescheduled or cancelled.
Also flight disruptions were reported during the wet season mainly due to heavy
downpours, severe thunderstorms and squally weather. On the 22nd August, flight
operations to Enugu, Port Harcourt and Owerri from the Murtala Mohammed Airport
Terminal 2 (MMA2), Lagos, were cancelled due to bad weather.
In December, winter weather in Europe led to flight disruptions to and from European
airports. These harsh weather conditions affected the number of inbound/ outbound flights
at the Murtala Mohammed International Airport, Lagos and also at the Nnamdi Azikiwe
International Airport, Abuja.
36
10.0
SUMMARY
The Inter-Tropical Discontinuity (ITD) maintained an average position of latitude 7.2 oN
in January and moved northwards thereafter to latitude 11.1oN by end of February
instead of the climatological southward movement. This development contributed to
the February destructive storm over Lagos and adjoining areas in Ogun state. From
March, the ITD commenced its seasonal northward movement and reached the northmost limit of latitude 18.8oN in the second dekad of August and retreated southwards
to attain an average position of latitude 7.6oN in December.
Maximum temperatures in the hot season (February and March in the south, and
March and April in the north) were 0.5 – 2.5oC warmer than normal in the north but
normal in the south except over the extreme southeast where temperatures were 0.5 –
1.5oC colder than normal. The cold season (January) temperatures were normal in most
places across the country. However, few places such as Sokoto, Katsina, Jos, Ilorin,
Iseyin, Oshogbo, Akure, Benin, Owerri and Enugu experienced 0.5 – 3.2oC colder
conditions.
Rainfall was normal to wetter than normal except for isolated places (Gusau, Shaki)
where rainfall was below the long term amount. For the first time since 2008, the
northeast had rainfall more than normal values. The year recorded the wettest
condition in the northeast in more than ten consecutive years.
The 1-2 months of more rainfall in the extreme north, generally normal rainfall
months in other parts of the country, coupled with the good rainfall especially over the
eastern halve of the country, contributed to the extensive flooding. The country
experienced the worst flooding in more than 80 years as a result of heavy rainfall in the
country coupled with the downstream flow from Fouta Djallon in Guinea and the
release of water from some dams within and outside the country in July. Joint survey by
the UN, Federal Government, NEMA and some Universities in the country showed that
33 states and the FCT were affected, including 14 states that were considered severely
affected. A total of 7,705,378 people in 256 Local Government areas and 3,870
communities were affected by the floods between July and October. Kogi state
recorded the highest number of affected people (1.35 million) followed by Adamawa
(1.11 million) and Delta (785,000).
37
11.0
CLIMATE OUTLOOK FOR 2013
The global circulation outlook for 2013 shows that the current warm-neutral ENSO
condition is likely to last till the rainy season in Nigeria. However, the dynamical models
suggest warmer conditions compared to the statistical models even though the signals
are likely to maintain ENSO-neutral range. Sea surface temperatures (SSTs) in the
tropical Atlantic are slightly above normal with a tendency for cooling.
The harmattan season at the beginning of the year is expected to be normal. The hot
season is likely to be normal also in many parts of the country but high daily
temperatures are not ruled out. The rains are expected to start around first week of
March in the south and late June in the far north. Chances of late onset of rains are
weak. The end of rainy season is likely to come between mid October in the North and
December in the South. This suggests a normal rainfall cessation in the country.
However, some inland areas of the south have prospect of early cessation. Further
analyses indicate likely higher rainfall amount than 2012 values in the eastern and
western flanks of the Central States which also suggests higher rainfall intensity.
There is evidence therefore that these characteristics of weather over Nigeria could
negatively impact on agriculture, water resources and health, even though near normal
rainfall is predicted especially over the eastern and western flanks of the Central States,
including the flood plains in the south and coastal areas.
38
12.0
Annex: THE GREAT FLOODS OF 2012
The year 2012 was very active in terms of flooding around the globe and Nigeria had its own
share of the devastating floods in the year. This section tries to sample the extent and
impact of these floods as captured by reports from various stakeholders and institutions.
12.1
LAGOS STATE
The country had barely come out of the Christmas and New Year celebrations when
Lagosians woke up in the morning of 14 February 2012 to be confronted with an early
morning rainstorm, which began at about 7.10 am, wreaked havoc in several parts of the
state, killing 15 persons, destroying many houses, cars, electric poles and uprooting many
trees. Several trees were also uprooted around Radio Nigeria, Ikoyi office which caused
severe damage to some cars parked in the area. The Third Mainland Bridge was also blocked
for most of the morning as street light poles felled by the storm lay on the road, obstructing
free flow of traffic.
www.vanguardngr.com
http://pmnewsnigeria.com
Fig 22: Impact of Storm on February 14, 2012
The battle against floods in the state continued in June after a short relief in March and
April, leaving behind tales of losses both in life and property amounting to huge sums of
money.
39
12.2
NIGERIA
Floods are among the most devastating natural disasters in the world, including Nigeria. The
spatial impact of floods and the people affected and displaced are more than in any other
disaster in Nigeria and the percentage of Nigerian population at risk of one form of flooding
or another is increasing. Flooding has become a major developmental challenge in the
country after the first flood hit Ibadan in 1948. Since then, high impact flood disasters have
occurred in the southwest and extending to the northern states, including but not limited to
Sokoto, Kano, Jigawa, Borno, Bauchi, Adamawa, Plateau, Taraba, Benue, Niger, Kogi, and
Kwara. The southeast states are not left out either from the perennial flooding and the
associated threats to human existence in the country.
In 2012, Nigeria experienced the worst flooding in more than 80 years as a result of heavy
rainfall in the country coupled with the downstream flow from Fouta Djallon in Guinea
through Niger Republic and the release of water from some dams within and outside the
country in July. Out of the 36 states of the country, 33 were affected, including 14 that were
considered severely affected. A total of 7,705,378 people in 256 Local Government areas
and 3,870 communes were affected by the floods between July and October. About 363
people were reported dead and over 18,200 people sustained different degrees of injury
while more than 618,000 houses were either destroyed or damaged.
Fig. 23: Map showing flooded states (Joint UN, FG, NEMA, Universities Survey)
Kogi state recorded the highest number of affected people (1.35 million) followed by
Adamawa (1.11 million) and Delta (785,000).
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The Nigeria Hydrological Services Agency (NIHSA) reported that the level of the Niger River
in Lokoja peaked at 12.8m on 29th September but fell to 8.8m high on 1st November as the
water started receding. The normal depth of the Niger River is about 6.5m.
12.3
GLOBAL
2012 will go down in history as one of the worst years of flooding and it will therefore be
interesting to sample the impact of these floods on the continents in this edition of the
Climate Review. Also a review of the 2012 Atlantic Hurricane season is included below.
AFRICA: Northern Hemisphere Summer rainfall across sub-Saharan Africa was above
average, with much of West Africa, specifically Senegal, south Mauritania, West and East
Mali, Niger, Nigeria, and northern Burkina Faso, having 40% or more above normal rainfall.
Several other countries in the continent particularly in eastern Africa had rainfall deficits,
recording not more than 70% of normal rainfall. Many countries in West Africa and the
Sahel, including Niger and Chad, suffered severe flooding between July and September
because of a very active monsoon.
The heavy rainfall prompted severe floods in 33 states across Nigeria which affected nearly
3million people, and caused fatalities. The floods destroyed farmlands, homes, and schools,
and caused outbreaks of cholera and other diseases. The torrential rainfall also caused floods
across parts of Niger, destroying thousands of homes, affecting over 480,000 people and
claiming lives. In Kenya, record-breaking rainfall events since 1926 occurred in May and
August leaving behind catalogue of woes.
EUROPE: The year saw record flooding in Europe as well. Between April and October,
heavy precipitations were recorded in the United Kingdom, France, Germany, parts of
southern Sweden, western Finland, western Russia, western part of mainland Estonia, south
of the Far East, etc. The wet weather and the heavy precipitation triggered flooding
The flooding led to loss of several thousands of lives and caused damages and destroyed
property amounting to several hundreds of millions of U.S. Dollars in agricultural and
infrastructure.
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AMERICA: Several tropical storms brought much needed precipitation to drought stricken
areas across the United States. Tropical Storm Debby dumped record rainfall totals across
Florida, contributing to Florida’s wettest June on record. Florida had its wettest summer on
record, partially driven by the storms Hurricane. Isaac brought heavy rainfall to southern
states, resulting in Louisiana and Mississippi’s second wettest August on record. The
beneficial rains across the region helped improve drought conditions across the Lower
Mississippi River Valley. Prior to reaching the U.S. mainland, Isaac dropped between 100.0–
200.0mm of rain across Puerto Rico, with locally heavier amounts across the interior
mountains. Extreme heavy rainfall severely affected the Buenos Aires province in Argentina
during August 2012, producing severe flooding and evacuations. Monthly totals broke
historical records (since 1875) in several locations across central and parts of northern
Argentina, with nearly double the previous records for the month of August in some places.
SOUTH AMERICA: Across northern South America, parts of Colombia were affected by
heavy precipitation during most of the year, with some areas recording daily totals between
150.0mm to 250.0 mm. The weather in Colombia during the first four months of the year
was influenced by La Niña, producing heavy rain across parts of the nation, leading to the
overflow of rivers and floods which affected thousands of people. Istmina, Chocó (northern
Colombia) recorded a total of 251.0 mm of rain on March 31st—the highest 24-hour rainfall
amount in March.
AUSTRALIA: In Australia, the most extensive flood events of the year occurred in late
February and early March, as a result of persistent heavy rain in a region extending from
eastern South Australia through most of southern inland New South Wales and northern
border areas of Victoria with weekly totals exceeding 200.0 mm over a large part of
southern New South Wales and adjacent areas of northern Victoria. Seven-day precipitation
averages for the Upper Murray (nearly 295.0 mm), Murrumbidgee (nearly 203.0 mm) and
Lachlan catchments (about 180.0 mm) were all nearly double the previous record high
values for any 7-day period. Parts of the Murrumbidgee and Lachlan Rivers reached their
highest flood peaks since 1974 and there were numerous evacuations in towns, including
Wagga Wagga, Hay, and Forbes.
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ASIA: Parts of southern China experienced their heaviest rainfall in the last 32 years as
torrential rain fell from April 5th to May 15th. In July, cities such as Beijing, Tianjin and Hebei
had torrential downpours, with several stations recording their highest daily precipitation
on record. Mentougou recorded an impressive amount of 305.2 mm precipitation in one
day. 114 deaths were attributed to the copious rainfall, with an economic loss of 4.5 billion
U.S. dollars. Devastating floods impacted Pakistan during September 2012. Monsoonal rains
prompted deadly floods across Pakistan, with Balochistan, Punjab, and Sindh the hardest hit
regions. Over 5 million people and over 400,000 hectares of crops have been affected by
floods, with more than 460,000 houses and infrastructures damaged or destroyed.
2012 ATLANTIC HURRICANE SEASON: The hurricane season was extremely active and
comparative with 1887, 1995, 2010 and 2011. Producing nineteen tropical cyclones and
named storms, ten hurricanes, and one major hurricane, the season began on June 1 and
ended on November 30. The season's first tropical cyclone, Tropical Storm Alberto,
developed on May 19, while the last storm, Tropical Storm Tony, dissipated on October 25.
The most intense hurricane, Sandy, was a powerful Category 2 hurricane that brought
significant damage to portions of the Greater Antilles and East Coast of the United States in
October 2012, causing damages in upwards to 65 billion dollars. Hurricane Sandy was the
largest known Atlantic hurricane by gale diameter on record. Hurricanes Sandy and Isaac
were the deadliest and most destructive, with the former causing at least $65.6 billion (2012
USD) in damage—the second costliest hurricane in recorded history—and 253 deaths, and
the latter causing an estimated $2.3 billion and 41 deaths
Despite the high number of hurricanes during the 2012 season, only one, Hurricane Michael,
attained major hurricane intensity—a Category 3 or higher on the Saffir-Simpson Hurricane
Wind Scale.
Source: Wikipedia the free encyclopaedia
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SAMPLE PICTURES OF 2012 FLOODS
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