Table of Content

FORWARD

1.0 Introduction

2.0 Evidence of Climate Change2.1 Rainfall Onset and Cessation2.2 Hail Frequency2.3 Mean Temperature

3.0 Synoptic Features 3.1 Surface Pressure3.2 Inter-Tropical Discontinuity (ITD)3.3 El-Nino

4.0 Temperatures 4.1 Hot Season Maximum Temperatures 4.2 Hot Season Maximum Temperature Anomaly 4.3 Cold Season Minimum Temperatures 4.4 Cold Season Minimum Temperature Anomaly 4.5 Annual Mean Temperature Anomaly

5.0 Solar Radiation

6.0 Rainfall 6.1 Cumulative Annual Rainfall 6.2 Rainfall Anomaly 6.3 August Rainfall Anomaly 6.4 Rainfall Months 6.5 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 State12.2 Nigeria

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12.3 GlobalFOREWORD

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 socio-

economic 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 decision-

making 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

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13.0 Sample Flood Pictures

scale’’ (World Climate Conference-3). Investment therefore in climate services translates to

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

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variability and change especially to the most vulnerable sectors of the economy and

communities to climate related hazards.

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.

4

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

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 40.0oC

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

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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.

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).

6

SOK KAT

BRKGUS KAN

DUT

ZAR

NG U

PO T DAM MAI

YEL

JEB

BAU

YOL

KAD

JOSMIN

BID

ILO

LO K MKD

GOM

IBI

JLG

KON

ABU

LAFSHK

BEN ABKENUOGJ

OTU

IKM

AKUOND

ONT

ISY OSB

OWE

ABE

IKEIJB

IBA

WAR

YEN

UMU

CALPHC

2.00 4.00 6.00 8.00 10.00 12 .00 14.00

Longitude (degrees E)

4.00

6.00

8.00

10 .00

12 .00

14 .00

Latit

ude

(deg

rees

N)

-2 .0

0.0

2.0

4.0

6.0

8.0

10 .0

12 .0

14 .0

16 .0

18 .0

20 .0

Fig. 1b: The Distribution of Anom aly of (1971-2000) minus (1911-1940) Mean Onset Dates of Dates of Rainy Season in Nigeria

Late O nset o f R ains

Norm al O nset o f Ra ins

SOK KAT

BRKG US KAN

DUT

ZAR

NG U

POT DAM MAI

YEL

JEB

BAU

YOL

KAD

JOSMIN

BID

ILO

LOK MKD

GOM

IBI

JLG

KON

ABU

LAFSHK

BEN ABKENUOGJ

OTU

IKM

AKUO ND

ONT

ISY OSB

OWE

ABE

IKEIJB

IBA

WAR

YEN

UMU

CALPHC

2.00 4.00 6.00 8.00 10.00 12.00 14.00

Long itude (degrees E)

4.00

6.00

8.00

10.00

12.00

14.00

Latit

ude

(deg

rees

N)

-6.0

-4.0

-2.0

0.0

2.0

4.0

6.0

8.0

10 .0

12 .0

Early O nset of R ains

Norm al Onset o f R ains

Late O nset o f R ains

Fig. 1a: The Distribution of Anomaly of (1941-1970) minus (1911-1940) Mean O nset Dates of Dates of R ainy Season in Nigeria

Fig. 1a: Onset dates anomaly: 1941-1970 Fig. 1b: Onset dates anomaly: 1971-2000

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).

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

SO K KAT

BRKGUS KAN

DUT

ZAR

NGU

POT DAM MAI

YEL

JEB

BAU

YOL

KAD

JOSMIN

BID

ILO

LOK MKD

GOM

IBI

JLG

KO N

ABU

LAFSHK

BEN ABKENUOGJ

OTU

IKM

AKUOND

ONT

ISY OSB

OWE

ABE

IKEIJB

IBA

WAR

YEN

UMU

CALPHC

2.00 4.00 6.00 8.00 10.00 12.00 14.00

Longitude (degrees E )

4.00

6.00

8.00

10.00

12.00

14.00

Latit

ude

(deg

rees

N)

-7 .0-6 .5-6 .0-5 .5-5 .0-4 .5-4 .0-3 .5-3 .0-2 .5-2 .0-1 .5-1 .0-0 .50.00.51.01.52.02.53.03.5

Early Cessation of R ains

N orm al C essa tion of R ains

Fig. 2a: The Distribution of Anom aly of (1941-1970) m inus (1911-1940) Mean Cessation Dates of Dates of Rainy Season in Nigeria

SOK KAT

BRKGUS KAN

DUT

ZAR

NGU

POT DAM MAI

YEL

JEB

BAU

YOL

KAD

JOSMIN

BID

ILO

LOK MKD

GOM

IBI

JLG

KO N

ABU

LAFSHK

BEN ABKENUOG J

OTU

IKM

AKUOND

ONT

ISY OSB

OW E

ABE

IKEIJB

IBA

WAR

YEN

UMU

CALPHC

2.00 4.00 6.00 8.00 10.00 12.00 14.00

Longitude (degrees E)

4.00

6.00

8.00

10.00

12.00

14.00

Latit

ude

(deg

rees

N)

-15.0

-14.0

-13.0

-12.0

-11.0

-10.0

-9 .0

-8 .0

-7 .0

-6 .0

-5 .0

-4 .0

-3 .0

-2 .0

Fig. 2b: The Distribution of Anom aly of (1971-2000) m inus (1911-1940) Mean Cessation Dates of Dates of Rainy Season in Nigeria

Early C essation of R ains

N orm al C essa tion o f R a ins

Fig. 2b: Cessation dates anomaly: 1971-2000Fig. 2a: Cessation dates anomaly: 1941-1970

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.

1942-1951 1952-1961 1962-1971 1972-1981 1982-1991 1992-2001 2002-20100

5

10

15

20

25

30

35

40

45

FREQ

UEN

CY

Fig. 3: Jos Hail Frequency 1942 - 2010

8

2.3 MEAN TEMPERATURE

Temperatures across the country show an increasing trend from mid 20 th century to date.

The mean temperature anomaly (Fig. 4a) shows clearly the prevalence of warming in the

country. Temperatures have increased from 0.2 – 0.5C in the high ground areas of Jos,

Yelwa and Ilorin in the north and Shaki, Iseyin and Ondo in the southwest to 0.9 - 1.9C over

the rest parts of the country.

2 4 6 8 10 12 142

4

6

8

10

12

14

0

0.5

1.5

2Key

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 (2.5C) than in the

north (1.4C).

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

10

Fig. 4b: Hot season temperature in the north 1941-2010

Fig. 4c: Hot season temperature in the south 1941-2010

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.

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.

11

10 30

4095

9 10 30

4101

9 10 30

4108

0 10 30

4114

1 10 30

4120

2 10 30

4126

3

3.05.07.09.0

11.013.015.017.019.021.0

2012 NORMAL

LAT

(deg

. N)

Fig. 5: Dekad positions of ITD in 2012

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.

Fig: 6. 2012 ITD position Anomaly.

12

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

-2.0

-1.0

0.0

1.0

2.0

3.0

4.0

5.0

6.0

LATI

TUD

E (D

egC)

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 ENSO-

neutral condition. The remaining months of the year clearly indicated ENSO-neutral

conditions despite above average SSTs.

Fig. 7: Oceanic Nino Index (ONI) over Nino 3.4 region

The second half of 2012 clearly showed warm-neutral ENSO condition. Upper and lower-

level zonal winds were near average, and convection was slightly suppressed over most of

13

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

-1-0.8-0.6-0.4-0.2

00.20.40.60.8

Oceanic Nino Index (ONI) for 2012

Tem

pera

ture

(deg

.C)

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.

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

2 4 6 8 10 12 142

4

6

8

10

12

14

30

33

36

38

40

Long (E)

Lat (

N)

Fig. 8: 2012 Hot Season Maximum Temperature

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.

15

2 4 6 8 10 12 142

4

6

8

10

12

14

-2 .5

-1.5

-0.5

0.5

1.5

2.5

Key

Long (E)

Lat (

N)

War

mer

than

N

orm

al

Normal

Col

der

than

N

orm

al

Fig. 9: 2012 Hot Season Maximum Temperature Anomaly

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.

16

Lower minimum temperatures were recorded in the extreme northeast and Jos in the cold

season of 2011 than over the same area in 2012.

2 4 6 8 10 12 142

4

6

8

10

12

14

10

14

18

22

24Key

Long (E)

Lat (

N)

Fig. 10: 2012 Cold Season Minimum Temperature

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.

17

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.

2 4 6 8 10 12 142

4

6

8

10

12

14

-3.5

-2

-0.5

0.5

2Key

Long (E)

Lat (

N)

Normal

War

mer

than

N

orm

alC

olde

r tha

n N

orm

al

Fig. 11: 2012 Cold Season Minimum Temperature Anomaly

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

18

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.

2 4 6 8 10 12 14

2

4

6

8

10

12

14

-1.5

-1

-0.5

0.5

1

1.5

Long (E)

Lat (

N)

Normal

Warm

er tha

n Norm

alCo

lder th

an No

rmal

K ey

Fig. 12: 2012 Mean Temperature Anomaly

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.

19

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.

2 4 6 8 10 12 142

4

6

8

10

12

14

18

20

22

24

26

28KEY

Long (E)

Lat (

N)

Fig. 13: Incident Solar Radiation in February 2012

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

20

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.

Long (E)

Lat (

N)

2 4 6 8 10 12 142

4

6

8

10

12

14

500

1000

2000

3000

4000

5000Key

Fig. 14: 2012 Cumulative Annual Rainfall

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.

21

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.

2 4 6 8 10 12 142

4

6

8

10

12

14

0

90

110

200Key

Long (E)

Lat (

N)

Normal

Wet

ter

than

N

orm

alD

rier

than

N

orm

al

Fig. 15a: 2012 Rainfall Anomaly

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.

22

2 4 6 8 10 12 142

4

6

8

10

12

14

A BE

A BU

A KU

B AU

B EN

B ID

C A L

E NU

G U S

IB A

IB I

IJEIK E

ILO

IS E

JO S

K AD

K AN

K AT

LO K M A K

M IN

N G U

O N D

O W E

P O R

P O T

S H A

S O K

U Y OW A R

Y EL

Y O L

ZA R

60

80

100

120

140

160

180

Lat (

N)

Long (E)

Low

er H

igh

er

Key

Fig. 15b: 2012 Rainfall in percentage of 2011 Rainfall

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.

23

2 4 6 8 10 12 142

4

6

8

10

12

14

A BE

A BU

A KU

B AU

B EN

B ID

C A L

E NU

G U S

IB A

IB I

IJEIK E

ILO

IS E

JO S

K AD

K AN

K AT

LO K M A K

M IN

N G U

O N D

O W E

P O R

P O T

S H A

S O K

U Y OW A R

Y EL

Y O L

ZA R

60

80

100

120

140

160

180

Lat (

N)

Long (E)

Low

er H

igh

er

Key

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.

2 4 6 8 10 12 14

2

4

6

8

10

12

14

10

90

110

200

250

Long (E)

Lat (

N)

Wet

ter t

han

Nor

mal

Dri

er th

an N

orm

al

Key

Normal

Fig. 16: 2012 August Rainfall Anomaly (%)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

24

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.

2 4 6 8 10 12 142

4

6

8

10

12

14

-2

-1

-0.5

0.5

1

2Key

Normal

Wet

ter

than

N

orm

alD

rier

than

N

orm

al

Long (E)

Lat (

N)

2

1

-1

-2

Fig. 17: 2012 Rainfall months’ Anomaly

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,

25

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) 2012 Duration(Days)

2011 Duration(Days)

2010 Duration(Days)

2009 Duration(Days)

1 Abeokuta August 1- 17 17 22 6 36

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

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).

26

Abeo

Akur

e

Ikej

a

I-Ode

Iseyi

n

Ond

o

Osh

ogbo

Shak

i

Ibad

an

0

5

10

15

20

25

30

35

40

2012 2011 2010

Days

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.

JAN

FEB

MAR AP

R

MAY JU

N JUL

AUG

SEP

OCT

NO

V

DEC

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

2012 Normal

Rain

fall

(mm

)

Fig. 19: Monthly Rainfall in the Southwest (area averaged)

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. 27

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.

Date Number of spells Effects

January 1st – 21st 1

Visibility reduced to 200 – 800m in the north and 600 – 1000m in the south. Deterioration in visibility due to dust haze was wide spread.

28

February 2nd – 7th February 11th – 18th February 25th – 29th

3Visibility 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

8.0 EXTREME METEOROLOGICAL PARAMETERS

8.1 WIND SPEEDDestructive 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 29

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) MONTH1. Ikeja 60 February2. Ibadan 60 May3. Jos 70 May4. Abuja 60 May5 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 Station Value (oC ) Period Frequency (Days)1 Maiduguri 44.7 February - May 53

2 Nguru 43.6 March - May 573 Sokoto 43.6 February - May 514 Yelwa 43.5 February - May 41

5 Potiskum 42.4 March - May 486 Gusau 42.2 February - May 307 Kano 42.1 March - May 388 Yola 42.1 February - May 609 Katsina 42.0 April - May 3410 Ibi 41.2 March 1011 Bauchi 41.0 March - May 2912 Gombe 41.0 April 913 Lafia 40.8 March 1614 Minna 40.8 March 715 Makurdi 40.3 March 416 Bida 40.0 March 10Table 4: High Daily Temperatures in 2012

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,

30

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 Port Harcourt 100.2 May2 Calabar 100.7 June3 Abeokuta 134.2 June4 Eket 121.8 June5 Ijebu- Ode 110.1 June6 Ikeja 216.3 June7 Ogoja 101.3 June8 Oshogbo 117.9 June9 Uyo 105.6 June10 Uyo 158.4 June11 Oshodi 225.8 June12 Lagos Island 169.8 June13 Lagos Marine 115.3 June14 Calabar 132.8 July15 Ijebu-Ode 132.5 July16 Maiduguri 107.3 July17 Owerri 128.8 July18 Uyo 111.7 July19 Warri 113.6 July20 Calabar 123.8 August21 Gombe 120.4 August22 Kano 143.0 August23 Zaria 158.4 August

Table 5: Daily rainfall of 100.0mm and higher in 2012

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.

31

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).

Rice Sorghum Cassava Yams Maize0

100,000

200,000

300,000

400,000

500,000

600,000

Ha

Fig. 20: Estimated Crop Loss (ha)

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

32

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).

Fig. 21: Estimated Fisheries Loss

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

33

Adam

awa

Anam

bra

Baye

lsa

Benu

e

Del

ta

Edo

Imo

Jigaw

a

Keb

bi

Kogi

Kwar

a

Nig

er

Plat

eau

Tara

ba

0

10,000,000

20,000,000

30,000,000

40,000,000

50,000,000

60,000,000

70,000,000

80,000,000

Nai

ra

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.

9.3 EDUCATION

34

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

9.4 HYDROLOGY

35

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. 9.5 AVIATION

36

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.

10.0 SUMMARY

37

The Inter-Tropical Discontinuity (ITD) maintained an average position of latitude 7.2oN

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 north-

most 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).

11.0 CLIMATE OUTLOOK FOR 201338

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.

39

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.

40

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).

41

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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