Evaluation of Water Scarcity in Africa

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Evaluation of Water Scarcity in Africa

• Todd J. Schram

CE 394K.2 Surface Water Hydrology Term
Project Spring 1999 Dr. David Maidment
Nile River, Cairo
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Overview

• Concepts of Water Scarcity
• Data Sources
• Water Resources
• Population Projections
• Evaluation of Scarcity
• Assessment of Climate Change
• Future Work

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Water Scarcity Concepts

• Water Stress Index
• approximate min. level of water required per
  capita to maintain adequate quality of life in a
  moderately developed country in an arid zone
• developed by Swedish hydrologist M. Falkenmark

• Benchmarks
• Used by UN and World Bank as tool to evaluate
  water supply abundance of country

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Consequences of Water Scarcity

• Why should we be concerned?
• Deterioration of water quality
• Costs of producing/delivering water increases
  rapidly
• Constrains economic development
• Statistics for Developing Countries
• 80 of diseases caused by contaminated water
• 1/3 of all deaths attributed to water-related
  diseases

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Changes in Water Scarcity

• Water Demand
• Population growth
• Industrialization
• Water conservation initiatives
• Water Supply
• Climate variability
• Climate change

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Sources of Data

• UNEP-GRID
• Population Data
• World Resource Institute
• Water Resources Data
• ESRI
• Political Boundaries
• ERBE
• Net Radiation
• Geography Dept. (University of Delaware)
• Precipitation Temperature

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Data Characterization

• Population Count Raster Dataset
• Resolution 1o cells
• Tabular data converted to grid of 5,986 cells
• Freshwater Resources
• 1) Spatially distributed value based on country
• 2) Annual runoff from gridded precipitation and
  evaporation data

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Annual Renewable Freshwater Resources
Total Volume (cubic kilometers)
Note Based on water resources of the country.
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Development of Population Count Grid
Arc/Info
ArcView
Generate Fishnet Build Polygons
Table/Join Data with Attributes Create Feature
Data Theme
Project Theme to Lambert Azimuthal Equal Area
Convert to Grid
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Population Count Grids
Year 2000
Year 2025
Year 2050
Population Count per Cell
Note Cell size is 1o x 1o.
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Evaluations of Scarcity Conditions

• Immediate Factor
• Effect of population growth on scarcity
• Analyzed using Water Stress Index benchmarks
• Long Term Factor
• Effect of climate change on scarcity
• Methodology presented

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Extent of Water Scarcity
Year 2000
Year 2025
Year 2050
Water Scarcity Designations
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Annual Hydrologic Data
Temperature (oC)
Precipitation (mm)
Net Radiation (W/m2)
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Assessment of Climate Change

• National Level
• USGS Global Change Hydrology Program
• Hydroclimatology
• International Level
• US Country Studies Program
• Assessment of Water Resources Vulnerability and
  Adaptation to Climate Change
• Recommends annual stochastic approach for areas
  with insufficient data
• Q P - E
• Q - Runoff P - Precipitation E - Evaporation
• Use of GCM or Incremental scenarios

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Evaporation Calculation

• Priestly-Taylor Evaporation Equation
• Applicable to continental scale
• Parameters
• Potential evaporation
• Net Radiation
• Temperature
• Saturated vapor pressure
• Latent heat of vaporization

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Conclusions

• Water scarcity maps due to population growth
• Evaluate future water shortages of countries
  within next 60 years
• Effects of future climate changes
• Not easily determined
• Can determine temperature change effects

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Available Reports

• World Resource Institute (WRI)
• World Resources 1998-1999
• World Bank
• World Development 1999
• World Water Organization
• The Worlds Water The Biennial Report on
  Freshwater Resources, 1998-1999
• Population Action International
• Sustaining Water Population and the Future of
  Renewable Water Supplies
• UN - Commission on Sustainable Development
• Comprehensive Assessment of the Freshwater
  Resources of the World
• U.S. Country Studies Program
• Assessment of Water Resources Vulnerability and
  Adaptation to Climate Change
• UN Food and Agriculture Organization (FAO)
• Water and Social Resource Scarcity
• AQUASTAT

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Future Work

• Utilize annual hydrologic data to
• conduct spatial evaluation to determine local
  regions of water scarcity
• determine impact of climatic temperature change
  on water scarcity

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Questions?
Lake Victoria, Uganda