ZAHRAH N. MUSA, IOANA POPESCU, ARTHUR MYNETT ZAHRAH N. MUSA, IOANA - PowerPoint PPT Presentation

ZAHRAH N. MUSA, IOANA POPESCU, ARTHUR MYNETT ZAHRAH N. MUSA, IOANA POPESCU, ARTHUR MYNETT UNESCO UNESCO - IHE, Institute for Water Education IHE, Institute for Water Education Delft, The Netherlands Delft, The Netherlands 1

Focus on coastal areas Focus on coastal areas of world's population lives –UN within km of the coast o high coastal population growth o high economic productivity high economic productivity o economic hubs of their countries (e.g. Rotterdam, Mumbai, Lagos, Guangzhou, etc) Low elevation Gentle slopes Gentle slopes 2

Focus on coastal areas Focus on coastal areas Climate change o Rise in atmospheric temperature o Rise in sea surface temperature Consequences of climate change o Global warming o Global warming o Change in precipitation patterns •Increase/decrease o Increased frequency of floods o o Rise in sea levels •Increased frequency of storm surges •Cyclones •Flooding •Flooding •Intrusion of sea salts •Inundation 3

Focus on coastal areas Focus on coastal areas Inundation from SLR impeding drainage of river flood waters impeding drainage of river flood waters inland movement of the shoreline uplifting the groundwater table o Loss of dry land o Loss of dry land o Loss of wetlands o Conversion of fresh water regimes to salt water regimes o Loss of natural biodiversity o Loss of natural biodiversity o creates a need for adaptation Dry land becomes a wetland, swamp or a part of a river, Dry land becomes a wetland, swamp or a part of a river, ocean /sea. 4

The low er Niger delta The low er Niger delta http://www.marxist.com/nigeria - congress - 2013.htm Area ~ 20,000 Km 2 20,000 450 km of coastline Made up of nine states in the southern part of Nigeria Nigeria’s economic hub rich in oil and gas main source of foreign main source of foreign exchange http://en.wikipedia.org/wiki/File:NigerDeltaStates.png 5

The low er Niger delta The low er Niger delta Environmental problems Natural o River flooding o River flooding (Niger, Imo, Qua Iboe ) o Erosion due to river and coastal flooding o Subsidence Man-made Man-made o Wood logging o deforestation o Oil spills o land loss o land loss o Contamination of surface water o Acid rain from gas flaring o corrodes roofing sheets o corrodes roofing sheets http://www.nairaland.com/587622/niger - delta - pictures o destroys biodiversity o Subsidence from oil and gas extraction 6

The Low er Niger Delta The Low er Niger Delta Hydrology: Rivers, Creeks, Lakes, Creeks, Lakes, Estuaries 7

The Low er Niger Delta The Low er Niger Delta Physical properties • Low elevation • Low elevation • Gentle slope • Subsiding due to oil and gas exploration • estimated at 25-125 mm/yr • estimated at 25-125 mm/yr 8

The Low er Niger Delta The Low er Niger Delta Vulnerability to inundation Method: Modified Bath Tub approach using GIS to map inundation Method: Modified Bath Tub approach using GIS to map inundation from sea level rise SRTM DEM Tidal surface: the longitude, latitude and Tidal surface: the longitude, latitude and water levels of 15 tide gauges located in NigeriaSat1 image the Niger delta. tidal surface tidal surface o Interpolate a raster o Interpolate a raster projected SLR values • Rahmstorf predicted values values 9

Vulnerability to inundation Vulnerability to inundation Vulnerability to inundation Vulnerability to inundation SLR inundation process Total surface area = 23,623.4 km 2 •Subset from NigeriaSat 1 image SLR values SLR values •2030 = 0.12 m - 0.41 m •2050 = 0.23 m - 0.65 m Tidal surface+ SLR = new water level New water level – SRTM value = inundated area New water level – SRTM value = inundated area 10

Vulnerability to inundation Vulnerability to inundation SLR only inundation extents SLR only inundation extents • 0.12 m by 2030 = 536.6 km 2 • = 2.3% • = 2.3% of the total surface area . . • 0.41 m by 2030 = 619.2 km 2 • 0.41 m by 2030 = 619.2 km 2 •= 2.6% of the total surface area . 11

Vulnerability to inundation Vulnerability to inundation SLR only inundation extents • 0.23 m by 2050= 562.8 km 2 562.8 km 2 •= 2.4% of the total surface area. area. • 0.65 m by 2050= 763.6 km 2 2 763.6 • = 3.2% of the total surface area. area. 12

Vulnerability to inundation Vulnerability to inundation SLR plus Subsidence inundation extents Land subsidence value = 25 mm/yr •2030 =0.75 m, and 2050= 1.25 m •2030 =0.75 m, and 2050= 1.25 m Land subsidence value +SLR + surface grid = new water level grid = new water level New water level – SRTM = inundated area 13

Vulnerability to inundation Vulnerability to inundation Vulnerability to inundation Vulnerability to inundation SLR plus Subsidence inundation extents • SLR (0.12 m ) + subsidence (0.75 m ) by 2030 • inundation extent = 791.8 km 2 • inundation extent = 791.8 km 2 • = 3.4% of the total surface area. • SLR (0.41 m ) + subsidence (0.75 m ) by • SLR (0.41 m ) + subsidence (0.75 m ) by 2030, • inundation extent = 1090.3 km 2 • inundation extent = 1090.3 km • 4.6% of the total surface area. 14

Vulnerability to inundation Vulnerability to inundation SLR plus Subsidence inundation extents • SLR (0.23 m ) + subsidence (1.25 m ) by 2050 • inundation extent = 1,511 km 2 • = 6.4% of the total surface area . • = 6.4% of the total surface area . • SLR (0.65 m ) + subsidence (1.25 m ) by 2050 • inundation extent =1,759.5 km 2 • inundation extent =1,759.5 km 2 • = 7.5% of the total surface area . 15

Vulnerability to inundation Vulnerability to inundation Implication •2.3 to 3.2% of the Niger delta could be inundated due to SLR by 2050 . inundated due to SLR by 2050 . •3.4 to 7.5% of the Niger delta could be •3.4 to 7.5% of the Niger delta could be inundated due to SLR and land subsidence by 2050 . Places affected… 16

Vulnerability to inundation Vulnerability to inundation Places affected…. 17

Vulnerability to inundation Vulnerability to inundation Population density… 18

Conclusion Conclusion Conclusion Conclusion The Niger delta is vulnerable to inundation by SLR o 2.3 to 3.2% could be inundated due to SLR by 2050 . o 2.3 to 3.2% could be inundated due to SLR by 2050 . Land subsidence will exacerbate the inundation effect of SLR on inland areas on inland areas o 3.4 to 7.5% could be inundated due to SLR + land subsidence by 2050 . Based on projected population census data , 460,000 to 2.4 million people could be affected by SLR by the year 2050 . 2.4 million people could be affected by SLR by the year 2050 . 19

Email: z.musa@unesco - ihe.org 20