Water file1-1
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This document discusses water scarcity and defines key terms. It provides multiple definitions and measures of scarcity based on water availability per capita. Countries with availability below 1000 cubic meters per person are considered water scarce. Scarcity is a relative term based on supply and demand in a given location. The document also examines causes of scarcity like agriculture, domestic and industrial use, pollution, and climate change. It distinguishes between physical and institutional scarcity. Graphs and maps show declining groundwater levels and impacts of overuse like increased costs, decreased quality, land loss, and subsidence.
Water file1-1
- 1. scarcity?
- 2. Water Scarcity “Water is life” Prof Kader Asmal, Chairman, World Commission on Dams “Whiskey is for drinking, water is for fightin’ over” Mark Twain, commenting on water conflicts in the American Midwest “We have one common goal: to provide water security in the 21st Century” Ministerial Declaration of The Hague, World Water Forum, April 2002
- 3. What is Scarcity? Water shortage, water scarcity, and water stress are three terms used in the discussion of how to meet human water needs
- 4. What is Scarcity? Assuming a minimum need for renewable water per person of 1,000 cubic meters: 20 countries, mostly in the Middle East and North Africa (MENA), are at or below this level now At 2,000 cubic meters per person: water is potentially a serious constraint, especially in drought years, and about 40 countries fall in this range, according to the FAO. While these may be reasonable benchmarks for water shortage, the issue really is one of supply and demand, and so scarcity is a relative term
- 5. What is Scarcity? From a water planning perspective, it is argued that – shortage is absolute – scarcity is relative – stress is a sign of approaching scarcity or shortage For example, Tunisia and Kenya both have water availability less than 1000 m3 per capita, but demand is less than supply
- 6. What is Scarcity? Regardless of definition, in most areas: – demand is increasing faster than supply – so scarcity is increasing
- 7. Measures of Scarcity Stress Level Description People competing for a million m3 of water Water availability per capita (1000s m3) 1 Water surplus < 200 >5 2 Water management 200 - 600 1.67 – 5.0 problems 3 Water stress 600 - 1000 1.0 - 1.67 4 Absolute scarcity 1000 - 2000 0.5 – 1.67 5 Beyond water barrier > 2000 <0.5 Source: Falkenmark, 1989
- 8. Measures of Scarcity Source: UNEP, 2002
- 9. Measures of Scarcity Stress Level Description Demand/Supply 1 Low < 0.1 or 10% 2 Moderate 0.1 to 0.2 3 Medium-high 0.2 to 0.4 4 High > 0.4 or 40% Source: UN/WMO, 1997
- 10. Causes of Scarcity (assuming climate is constant) • • • • • Agriculture Domestic water use Industrial water use Pollution Climate change
- 11. Causes of Scarcity Source: Gleick et al., 2001
- 12. Pollution Source: Gleick et al., 2001
- 13. Pollution Percent population without access to adequate sanitation services Source: Gleick et al., 2001
- 14. Morbidity and Mortality from Water-related diseases Source: Gleick et al., 2001
- 15. Morbidity and Mortality from Water-related diseases Source: Gleick et al., 2001
- 16. Types of Scarcity • First order scarcity – a physical shortage of water • Second order scarcity – an institutional inability to satisfy demand or deliver clean water • None of the maps shown take account of second order scarcity
- 17. Drop in Groundwater Level
- 18. Impacts of groundwater over-pumping • • • • Increased costs Decreased water quality Loss of farmland Subsidence
- 19. Subsidence