Download The Global Water System Project

The Global Water System Project
Dennis P. Lettenmaier
for
MAGS 10th Annual
Scientific Meeting
Vancouver, B.C.
November 5, 2004
Global Water System Project
(GWSP)
IGBP
Health
Global Water System Project
IGBP – IHDP – WCRP - Diversitas
Definition:
The Global Water System (GWS) is defined as the suite of
physical, chemical, biological, and human components [of
the global water cycle] and their interactions
Rational:
Humans have begun to affect the Global Water System
significantly without adequate understanding of how
the system works
Mission:
Improve knowledge of, and responsible interaction with,
the Global Water System
e.g.
global observation
consolidation of global data sets
predictive and coupled modelling
Global Water System Project
IGBP – IHDP – WCRP - Diversitas
Central Tenet:
Human-induced changes to the
Global Water System are now
globally significant and are being
modified without adequate
understanding of how the system
works
What is Global Change?
• Global Change is more than Global Climate Change
• It has natural PLUS human/social dimensions
• A constellation of changes, many global in domain
For example, we see large changes in:
Richards (1991), WRI
(1990)
Mackenzie et al (2002)
Reid & Miller (1989)
U.S. Bureau of the Census
NOAA
Vitousek (1994)
Water Supply-- Doubling of Global Nitrogen Pollution
Green et al. 2003
• Humans are Key Agents of
Direct Hydrologic Change
• Pandemic Distortion of
Hydrographs
– Impoundment
– Consumptive Use
– Flow Diversion
– Land Cover Impacts (direct
& weather-mediated)
Macro-scale models of human runoff
distortion now being developed
1
0.9
1.6
0.8
1.4
0.7
1.2
0.6
1
0.5
0.8
0.4
0.6
0.3
0.4
0.2
0.2
0.1
0
0
0
1
2
3
4
5
6
7
Time(Month)
8
9
10
11
12
Storage (*mill. m3)
Inflow and Outflow,
Q(m^3/month)
2
1.8
Inflow
Outflow
Reservoir
An Acceleration of the Hydrological Cycle?
•Will climate become more variable?
•Will people move into harm’s way?
POPULATION (millions)
100
80
Population
exposed
60
40
20
0
1960-95 Sources
Of Extreme
Precipitation
Damage
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21>20
22 23
NUMBER OF DAYS: PRECIPITATION > 5 cm/day
Baseline Climate 53%
All other changes 47%
•Climate
12%
•Population 73%
•Interaction 15%
Drought Also Is A Key Issue
_______________
Population Above and
Below Water Stress
Threshold During Drought
-- 30-year duration statistics
Horn of
Africa
0
Sahel
Mean
30-yr drought
(millions)
Population
45
Sahel
Population
(in 1000s)
Horn Southeast
DIA/Q
< 0.4
>100
10 to 100
0 to 10
DIA/Q
> 0.4
>100
10 to 100
0 to 10
Southeastern
Africa
Continental total: Mean --> 25% population w/ stress
30-yr drought --> 40%
Global Water System Project
IGBP – IHDP – WCRP - Diversitas
Science questions
I.
What are the magnitudes of anthropogenic and environmental
changes in the Global Water System and what are the key
mechanisms by which they are induced?
II.
What are the main linkages and feedbacks within the Earth
system arising from a changing Global Water System?
III.
How resilient and adaptable is the Global Water System to change,
and what are sustainable management strategies?
Joint Water Project
IGBP – IHDP – WCRP - Diversitas
Building blocks from the GEC programmes:
Global Water System Project
IGBP – IHDP – WCRP - Diversitas
Global assessment
of water scarcity
Crisis of Global Water Resources in 2025:
Climate or Population Growth
Vörösmarty, 2000
Global Water System Project
IGBP – IHDP – WCRP - Diversitas
Human modification
of hydrological systems
Historic Naturalized Flow
Estimated Range of
Naturalized Flow
With 2040’s Warming
Regulated Flow
Figure 1: mean seasonal hydrographs of the Columbia River prior to (blue) and after the completion of reservoirs
that now have storage capacity equal to about one-third of the river’s mean annual flow (red), and the projected
range of impacts on naturalized flows predicted to result from a range of global warming scenarios over the next
century. Climate change scenarios IPCC Data and Distribution Center, hydrologic simulations courtesy of A.
Hamlet, University of Washington.
Global Water System Project
IGBP – IHDP – WCRP - Diversitas
Global Water System Project
IGBP – IHDP – WCRP - Diversitas
Ludwig 1996
Riverine carbon fluxes
Global Water System Project
IGBP – IHDP – WCRP - Diversitas
Scoping team meetings:
• January, 2002 Reading (initial meeting)
• May, 2002 Paris (Scoping document finalized)
• January 2003, Bethesda MD (Scientific framework initialized)
• March 2003, Kyoto
• May 2003, Amsterdam
• October 2003, Portsmouth, NH (Open Science Conference)
Scoping team:
WCRP (2), IGBP (2), IHDP (2), Diversitas (1)
Post-OSC
•Scientific Framework finalized Summer 2004
•Chairs and Directors to appoint SSG (in progress)
Global Water System Project
IGBP – IHDP – WCRP - Diversitas
References:
• Scoping Document: http://www.gwsp.org/
• Draft Scientific Framework: http://www.gwsp.org/
• Open Science Conference: http://gwsposc.sr.unh.edu/