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.

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

20. Subsidence
1952
1985