RIVER BASIN
MAN AGEMEN T
Part 1
GLOBA L
FRESH
W A TER CRISIS?
RESOU RCES
W HAT
CRISIS?
AN
EN VIRON MEN T A L
IN T ERA CT ION

Water, water everywhere?
But how much water have we got all together?

97.5% of the water in our planet is in our oceans.
Too salty for use by humans.
The rest is fresh water though.
All 37 million
cubic kilometres of it!
So, no problem then?
Well…..

…most of it is locked up in icecaps
and glaciers

The Hydrological Cycle
A global model
From MacLean and Thomson
CORE HIGHER GEOGRAPHY

725 mm per annum

RIVER REGIMES
from River Basin Management Doherty
& McDonald

RIVER REGIMES

An Alluvial Fan in the Karakorum

Total runoff?
About 40,000 cubic kilometres

Total RELIABLE runoff?
About 10,000 cubic kilometres

from River Basin Management (Doherty and McDonald)

DOMESTIC: 100 cubic kilometres
n.b. we only need 10 to 30 litres for
basic health standards
Image: New Internationalist

INDUSTRIAL: 200 cubic kilometres

COOLING: 45 cubic kilometres

LIVESTOCK: 40 cubic kilometres

IRRIGATION: 3,300 cubic kilometres

MAJOR IRRIGATION SYSTEMS
from G. Tyler Miller: Sustaining the Earth, (Thomson)

Major Irrigation Systems
Gravity Flow Irrigation
(Efficiency 60% to 80%)

Drip Irrigation (efficiency 90% - 95%)

Central Pivot Irrigation
(efficiency 80% to 95%)
95

RESOURCES AND FURTHER READING
Vital Water Graphics from UNEP at
http://www.unep.org/dewa/assessments/ecosystems/water/vitalwater/freshwa
World Water Vision from the World Water Council at
http://www.worldwatercouncil.org/index.php?id=961
Sustaining the Earth, G.Tyler Miller,Jr., (2004), Thomson Learning
Changemakers Library - Tools for Social Change - Water at
http://proxied.changemakers.net/library/fieldlink.cfm-field=Water
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