Water Related Disasters: Prospects Under Climate Change Seleshi B. Awulachew

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Water Related Disasters: Prospects Under Climate Change Seleshi B. Awulachew African Climate Policy Centre (UNECA-ACPC) 25 June 2012. Outline. Introduction Water Related Disasters in Africa Occurrences of Water Disasters – Drought, Flood, Storm Prospects under Climate Change - PowerPoint PPT Presentation

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Water Related Disasters: Prospects Under Climate Change

Seleshi B. AwulachewAfrican Climate Policy Centre (UNECA-ACPC)25 June 20121ClimDev-AfricaUNECAOutlineIntroductionWater Related Disasters in AfricaOccurrences of Water Disasters Drought, Flood, StormProspects under Climate ChangeWater disaster implications to key sectorsCopping Mechanisms and MeasuresClimDev Africa and ACPCUNECA1. IntroductionDisaster is a serious disruption of the functioning of a society or community

Causes widespread human, material or environmental loss which exceeds the capacity of the affected society to cope without external intervention

A disaster therefore an effect to the society of a hazardous occurrence(UN/ISDR)

UNECA1. Introduction: Disaster categoriesHydro-meteorological: Droughts/famine, Floods, Wind storms, Avalanches, landslides, extreme temperatures, heat waves, hurricanes, forest fires, insect infestations and storm surges

Geophysical disasters: Earthquakes, volcanoes, tsunami etc.

Water Disaster: Floods, Drought, Storm, Dam Break, (essentially linked to hydro-meteorology)

Water disasters are aggravated due to climate changeUNECA1. Introduction: Disaster TrendsNumber of people reported affected by natural disaster 1990-2010 (square rooted)

5UNECA1. Introduction: Disaster Damage CausedAverage annual damages ($US Billion) caused by reported natural disaster summary 1990-2010.

6UNECA At a global scale, water disasters are increasing under climate change The frequency of heavy precipitation events has increased over most land areas.

1. Introduction: Water and None Water Disasters7The annual total and cumulative number of natural disaster events recorded globally between 1900 and 2006 UNECA 1. Introduction: Manifestation of Water Disasters

Climate variability & occurrence of El Nino/La Nina in AfricaClimate change and sea level rise in AfricaIntense rainfall and land slide in AfricaIncreased coastal erosion and damage to coastal buildings and infrastructureIncrease monsoon precipitation variabilityIntensified droughts and floods associated with El Nio events in many different regionsDecreased agricultural and rangeland productivity in drought and flood-prone regionsDecreased hydro-power potential in drought-prone regionsThe occurrence of water and vector-borne diseases epidemics: cholera, malaria, leptospirosis and typhus.

UNECA2. Water Related Disasters in AfricaAfrica is one of the most vulnerable continents to climate variability and change because of multiple existing stresses and low adaptive capacity. Existing stresses include poverty, political conflicts, and ecosystem degradation.

Water Disaster Risk is projected to severely compromise agricultural production, including access to food, in many African countries and regions.

By 2050, between 350 million and 600 million people are projected to experience increased water stress due to climate change.

Fig. Africas climate zones by Ral Ivn Alfaro-Pelico, 2010UNECAAfrican Sahel - past 30 yearsA 25% decrease in rainfallHydro-meteorological disasters in Africa66.5% in 2000-200982.6% share in 2010 Drought and flood hit same places in the continent at different timesStrong relation betweenDrought and famineFlood and epidemic

102. Water Related Disasters in AfricaUNECA2. Water Related Disasters in Africa Climate extremes in AfricaHydrometeorlogical disasters in Africa (Shongwe et al., 2011)East Africa1980s 3 events per yr1990s 7 events per yr2000-200610 events per yrSouthern Africa 1980s 5 events per yr 2000-2006 18 events per yr11

Trends in drought and flood events in AfricaUNECA3. Water Disasters: Drought, Flood, Storm,Drought:A situation of moisture deficit with adverse effect on vegetation, animals, and man over considerable area

Meteorological drought:Abnormally dry, prolonged weather period for the lack of water to cause serious hydrologic imbalance in the affected area

Agricultural drought: A climatic condition involving a shortage of precipitation that adversely affect crop or pasture production

Hydrologic drought: A period of below average water content in streams, reservoirs, Groundwater aquifers, lakes and soils

Both agricultural and hydrologic droughts lag behind the meteorological droughtUNECA3. Water Disasters: Drought, Flood, Storm,Flood:Floods are caused by weather phenomena and events that deliver more precipitation to a drainage basin than can be readily absorbed or stored within the basin (USGS)Major types of flood include:Coastal FloodFlash FloodUrban FloodRiver FloodUNECADry Months Rainfall for Various Return Periods for the Upper Blue Nile Basin

DryWetUNECAWet Months Rainfall for Various Return Periods for the Upper Blue Nile Basin

DryWetUNECARainfall Runoff magnitude and frequecny16

Rainfall (red) and discharge (blue) frequency curves

UNECATanzania flooding (December, 2011)The heaviest rains since 1961


The Salender Bridge which was partly damaged by floods Conveyance capacity of drainage system is too low in most African cities due to improper design and constructionUNECAMany countries face multi-hazardsMozambiqueDroughtsFloodsSalt intrusion to groundwater Cyclones34 per year get to landfalls Kenya2011-2012 droughtRecently deadly flooding in some partsWe need to look at approaches that can help us to address risks from multi-hazards

18UNECA3. Water Disasters: Aggravating factorsEnvironmental degradationIncreases the intensity of natural hazards and is often the factor that transforms the hazard into a disasterRiver and lake floods are aggravated or even caused by deforestation which in turn causes erosion & river clogging.

Source: UNEP, International Soil Reference and Information Centre, World Atlas of Desertification, 1997Flood plain settlement Population often being concentrated in risky areas such as flood plainsE.g Gulf of guinea, costal areas of south east Africa, Nile delta and Wabishebelle river basin in East Africa.Climate change

UNECA4. Prospects under climate change: Scientific Consensus

The climate system is driven by solar radiation from the Sun

Phenomena that affect the energy balance of the climate system would ultimately alter the climate

UNECA204. Prospects under climate change: Scientific ConsensusGlobal warming is caused by the emission of GHG & their increasing concentration in the atmosphere due to human activities

Concentration of the major GHG has increased since 1750

Carbon dioxide (CO2) increased by 32%

Methane (CH4) increased by 150%

Nitrous Oxide (N2O) increased by 17%

The increase in atmospheric CO2:- fossil-fuel burning and land use change including deforestation

The increase in CH4 & N2O : - emissions from energy use, livestock, rice agriculture, and landfill.

UNECA214. Prospects under climate change: Scientific Consensus

Earths climate results from interactions of many processes in the components of the climate system: Anthropogenic system (human activities) disturb the balance

The climate system and hydrological balance change as a result

- temperature increase in Africa

- warm atmosphere which absorb more water vapor and an increase in humidity,

-more water moving through the hydrological cycle, more extreme event


Climate Change Mitigation and adaptation through better water managementMitigation is about gases.Adaptation is mainly about water.ClimDev-AfricaUNECAImpact of climate change snow melt- Climate change is already heating AfricaThe icecap on Kilimanjaro disappearing Reduction of the icecap by ~82% since 1912It may disappear within 15 yearsDrying out of several rivers


UNECAShrinking of Lake Chad

Lake Chad in a 2001 satellite image, with the actual lake in blue, and vegetation on top of the old lake bed in green. Above that, the changes from 1973 to 1997 are shown. Driven by climate change or land use change? UNECA4. Prospects under climate change sea level rise> 25 % of Africas population lives within 100 km of the coast30 percent of Africas coastal countries is at risk of inundationThe most flood risk occurs in North, West and Southern AfricaSmall IslandsImpacts of sea level rise: Reduced productivity of coastal fisheries; Migration and health issues; negative impacts on tourism; . In Alexandria, US$563.28 billion worth of assets could be damaged or lost due to coastal flooding alone by 2070

26UNECA5. Water disaster impacts to key sectors

Agricultural Sector (water infrastructures, irrigation development, production, productivity, seeds genotype, the sector development)Energy sector (hydropower) Health (human, animal) Environment (biodiversity, ecosystem equilibrium & sustainability) Economy (growth and sustainable development)Human settlement and migration (life, houses, livelihood)

27UNECAImpacts agriculture and economy Climate is already changing and Africa already impactedEthiopia: Extreme variability affecting GDP as agriculture is affectedBurkina Faso: Variability linked to cereal productivityKenya:30-50% around the mean- drought & flood

Loss in production, infrastructure, and increased poverty

UNECAImpacts: production, livelihood, settlementImpacts on Production SystemFlood Impacts on Shelter with displacement & migration from one area to anotherDrought influence infectious diseases such meningitis,Deplete food & cash savings


UNECAThe weak Infrastructures in AfricaNational SecurityImpact on the drinkable water and water sanitationRiver Basin

Impacts: production, livelihood, settlement30UNECA6. Water Disaster Managem


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