BY

SAVIOUR P. UDO-AKUAIBITINSTITUTE OF NATURAL RESOURCES, ENVIRONMENT

AND SUSTAINABLE DEVELOPMENT, UNIVERSITY OF

PORT HARCOURT, RIVERS STATE, NIGERIA.

at the 2nd International Conference on Oceanography, Las Vegas, USA., July 21-23, 2014.

OUTLINE

�INTRODUCTON

�STUDY AREA&TECHNIQUES

�RESULTS/DISCUSSION

�SUMMARY�SUMMARY

�CONCLUSION

INTRODUCTION

Coastal submergence and shoreline retreat are globalproblems which can be attributed to sea- level rise andclimate change. These constitute a serious threat toshoreline management in the Niger Delta.shoreline management in the Niger Delta.

This study is therefore aimed at analyzing shorelinerecession as a result of sea level rise and also examinesthe impact on the strand coast, south eastern Nigeria.

STUDY AREA &TECHNIQUES

� Period Sept.28-October 6, 2013

� Shoreline Mapping with GPS and camera.camera.

� Wave breaker parameters

� Beach profile surveys

The 2002 And 2013 Editions Of The Shoreline Maps Of The Study Area

STUDY AREA

Plate 1: Aerial photo of Qua-Iboe Estuary in 2002

Plate 2: Aerial photo of Qua-Iboe estuary showing areas of severe erosion in 2002

RESULT-ESTUARY: Current Velocities

-150

-100

-50

0

50

100

150

-20

-18

-16

-14

-12

-10 -8 -6 -4 -2 0 2 4 6 8

10

Ve

loci

ty(c

m/s

)

Time in half hourly interval relative to high water(0)

Estuarine current velocity-Updrift

Neap Tide

Mean Tide

Spring Tide

North

-100

-50

0

50

100

150

-20

-18

-16

-14

-12

-10 -8 -6 -4 -2 0 2 4 6 8

10Ve

loci

ty (

cm/s

)

Time in half hourly interval relative to high water(0)

Estuarine Current: Downdrift

Neap Tide

Mean Tide

Spring Tide

North

-150Time in half hourly interval relative to high water(0)

South

01020304050607080

Neap

Tide

Mean

Tide

Spring

Tide

Neap

Tide

Mean

Tide

Spring

Tide

Flood Tide Ebb tide

Ve

loci

ty(c

m/s

)

Average Flow Velocity:Estuary-

Updrift

-100Time in half hourly interval relative to high water(0)

South

0

10

20

30

40

50

60

Neap

Tide

Mean

Tide

Spring

Tide

Neap

Tide

Mean

Tide

Spring

Tide

Flood Tide(Northward) Ebb Tide(Southward)

Ve

loci

ty (

cm/s

)

Average Flow Velocity: Estuary-

Downdrift

Fig.4.Estuarine current velocity-Updrift

Fig.6.Average Flow Velocity:Estuary updrift

Fig.5.Estuarine current velocity:downdrift

Fig.7 Average Flow Velocity: Estuary Downdrift

RESULT-SURF ZONE: Longshore Current

-50

0

50

100

150

-20

-18

-16

-14

-12

-10 -8 -6 -4 -2 0 2 4 6 8

10

Ve

loci

ty(c

m/s

)

Fig. 8: Longshore current

velocity:Updrift station 1

Neap Tide

Mean Tide

Spring Tide

East

-50

0

50

100

-20

-18

-16

-14

-12

-10 -8 -6 -4 -2 0 2 4 6 8

10

Ve

loci

ty (

cm/s

)

Fig. 9: Longshore current

velocity:Downdrift station 1

Neap Tide

Mean Tide

Spring Tide

East

-150

-100

Time in half hourly interval relative to high water(0)West

0

20

40

60

80

100

120

Neap

Tide

Mean

Tide

Spring

Tide

Neap

Tide

Mean

Tide

Spring

Tide

East West

Ve

loci

ty (

cm/s

)

Fig.10: Average Longshore Current

Velocity: Updrift-Station 1

-100Time in half hourly interval relative to high water(0)

West

010203040506070

Neap

Tide

Mean

Tide

Spring

Tide

Neap

Tide

Mean

Tide

Spring

Tide

East West

Ve

loci

ty (

cm/s

)

Fig. 11: Average Longshore Current

Velocity:Downdrift Staiton 1

RESULT-SURF ZONE: UPDRIFT.ST.2

-WAVE PARAMETER

0

5

10

15

20

25

30

Wa

ve

Bre

ak

er

He

igh

t(cm

)

Fig 12: Wave Breaker height:Updrift

Neap Tide

0

10

20

30

40

50

60

70

Wa

ve

Bre

ak

er

He

igh

t(cm

)

Fig 13: Wave Breaker Height:

Downdrift

Neap Tide

Mean tide

SpringTide0

-20-18-16-14-12-10 -8 -6 -4 -2 0 2 4 6 8 10

Time in half hourly interval relative to high water(0)

0

-20 -18 -16 -14 -12 -10 -8 -6 -4 -2 0 2 4 6 8

Wa

ve

Bre

ak

er

He

igh

t(cm

)

Time in half hourly interval relative to high water(0)

SpringTide

Plate 3.Wave breaker Height -Updrift Plate 4: Wave breaker Height- Downdrift.

RESULT-UPDRIFT:BEACH PROFILE

-80

-60

-40

-20

0

20

40

0 1 2 3 4 5 6 7 8 9 10111213141516171819

Ele

va

tio

n(c

m)

Beach Profile:Updrift -Station 1

Neap Tide

Mean Tide

Spring Tide

-60

-40

-20

0

20

40

0 1 2 3 4 5 6 7 8 9 1011121314151617181920

Ele

va

tio

n(c

m)

Beach Profile:Updrift-Station 2

Neap Tide

Mean Tide

Spring Tide

-100Distance(x10m) -80

Distance(x10m)

Fig.14.Beach Profile: Updrift-Station 1 Fig.15. Beach Profile: Updrift Station 2

Plate 5:Backshore - Updrift Station 1 Plate6: Foreshore –Updrift Station 2

RESULT-DOWNDRIFT:BEACH PROFILE

-60

-50

-40

-30

-20

-10

0

10

20

30

0 1 2 3 4 5 6 7 8 9 10 11 12 13

Ele

va

tio

n(c

m)

Beach Profile:Downdrift-Station 1

Neap Tide

Mean Tide

Spring Tide

-60

-40

-20

0

20

40

60

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Ele

va

tio

n(c

m)

Beach Profile:Downdrift-Station 2

Neap Tide

Mean Tide

Spring Tide

-70

-60

Distance(x10m)-80

-60

Distance (x10m)

Fig.16.Beach Profile: Downdrift Station1 Fig17.Beach Profile: Downdrift-Station 2

Plate 7: Foreshore- Downdrift Station 1 Plate 8: Foreshore- Downdrift Station 2

HYDRODYNAMICS-EBB PHASE

Plate 9. Offshore sand bar –Updrift.

SHORELINE MANAGEMENT ISSUES

Plate 10 Stubb’s Creek sealed-up

with sediment during storm surge in

2011

Plate 11: Foreshore trough at updrift beach

Plate 12: Eroded backshore at updrift beachPlate 13 shoreline retreat due to storm surge

event at the updrift

SHORELINE MANAGEMENT ISSUES

Plate 14:Former Itak Abasi primary School Plate 15: Former Itak Abasi Health Centre Plate 14:Former Itak Abasi primary School

damaged by storm surge in 2011

Plate 15: Former Itak Abasi Health Centre

damaged by storm surge in 2011

Plate 16: Ibeno beach resort Plate17: sediment accretion at downdrift beach

SUMMARY This presentation has :

� Noted shoreline retreat and coastal submergencearound Qua-Iboe Estuary as impact of sea-level riseand climate change in Nigeria.

� Considered integrated coastal zone management� Considered integrated coastal zone managementapproach as essential in managing the shoreline retreatthrough intervention projects by both public andprivate sectors.

� Considered regular beach nourishment as a proactivemeasure to prevent shoreline retreat

CONCLUSION

� In conclusion, the coastal submergence andshoreline retreat along the south east coast ofNigeria which is attributed to sea-level rise relatedNigeria which is attributed to sea-level rise relatedstorm surge can be considered as a signature ofclimate change in Nigeria. Therefore, moreattentions should be given and concerted effortmade by the government and private sectors toreduce any anthropogenic activity which accelerateclimate change and sea-level rise.

CONTRIBUTION TO KNOWLEDGE

� The production of a recent shoreline map of the study area as a basis for assessment of sea-level rise along the strand coast of Akwa Ibom State, South-eastern strand coast of Akwa Ibom State, South-eastern Nigeria.

THANK YOUTHANK YOU

FOR FOR

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