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CHG Background
The problem – too much water or not enough. In many developing
nations coping with hydrologic extremes is equivalent in cost
and potential outcome to war (Kates,
2000). Many countries are losing this struggle for water.
According to a recent UN World Water Development report (WWD,
2003) the average supply of water per person world-wide
is expected to drop by a third in the next 20 years, with between
2 to 7 billion people facing water shortages by 2050. Fifty
nations face chronic food shortages, with 20% or more of their
populations under-nourished (FAO,
1999). Caught between increasing demand and shrinking opportunities,
many of the global poor adapt desperately, with displacements
and unsustainable agricultural practices that promote a spiral
of land degradation. The impact of drought is not limited to
the poorest nations. Economic growth for the Republic of South
Africa, for example, with a diverse economy ( only about 2%
of its GDP is based on agriculture), has a strong (0.7) positive
correlation with seasonal rainfall totals (Jury,
2002). Too much water may also bring disaster. Diseases
associated with wet conditions such as malaria and Rift Valley
Fever exact a tremendous toll on people and their livelihoods,
taking thousands of lives and costing billions of dollars (WHO,
2001), and account for 19% of all infectious disease-related
deaths (WHO, 2000). Furthermore,
flooding can eradicate years of painful economic advances, gained
through fiscal discipline and hard work, in a single week. Such
was the case for Honduras and Mozambique, when struck, respectively,
by Mitch and Eline in 1998 and 2000. Economic growth in Mozambique
went from 8% to 2% a year, almost overnight (BBC,
2001).
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Figure 2. USGS Stream flow
model output
for Mozambique, May 8th, 2003 (top-left),
photo and radar imagery of flooding in 1999 (top-right) and
tropical cyclone Mantua reaching Madagascar on May 8th, 2003.
Figure 1. Annual runoff
and scenes from Ethiopia. Enough water exists in many regions
to overcome drought. Better scientific management practices
of water resources is required.
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The solution – science
in action. The global water crisis has been caused
by “inertia at the leadership level” (WWD,
2003). Limited hydrologic science and resources contribute
to this inertia. Effective decision-making grows out of the
clash and conflict of many diverging opinions (Drucker,
1967). Where scientific inquiry is stunted, the possibilities
for future development wither (Einstein,
1949). From the dawn of history, successful cultures have
had the means to anticipate, mitigate and alleviate the impacts
of hydrologic extremes (Fagan,
1999). Current science combines ever-growing satellite-based
observations with constantly improving models of our climate,
rivers and crops to provide better and better information
sooner faster and cheaper than ever before. Science tells
us that many of the water-related emergencies of the developing
world can be effectively mitigated. Average grain yields have
doubled since 1950, and per-person caloric intake has increased
(WWD, 2003). Improved
hydrologic forecasting and management practices can continue
this trend. For example, Ethiopia, chronically stricken by
drought, has substantial annual surpluses of runoff –
which could be stored in ponds and used to offset the effects
of drought (Rockstrom, 2000)
(Figure 1). Stream flow models operating in near-real time
and in forecast mode can identify at-risk basins, allowing
the worst effects of flooding to be avoided (Figure 2). Seasonal
precipitation forecasts can provide guidance months in advance,
allowing nations to adequately prepare themselves for higher
than normal rains (as expected for Central America this summer,
Figure 3), or for the specter of drought (as was correctly
anticipated this past winter in Southern Africa, Figure 4).
These results stem from the work of an international team
of Famine Early Warning System Network (FEWS NET) scientists
working in the United States and abroad. Research scientists
in the United States, with full access to the fruits of technology,
are well-situated to rapidly develop new theories and tools.
Regional scientists, stationed in developing countries, can
translate new theories and tools rapidly into practice, and
communicate their results to decision makers. This model of
‘science for development’ has proven effective
for the CHG.
Figure 3. Forecast seasonal
precipitation anomalies [mm/season] for the 2003 La Primera
(June-August) maize growing season in Central America. Based
on an interpretation of the International Research Institute
Climate Assessment. Also shown are scenes of devastation caused
by Hurricane Mitch.
Figure 4. Comparison
of maize Water Requirement Satisfaction Index forecast (made
in mid-November, 2002) with current end-of-season values for
Southern Africa. Values are expressed as a percent of the
historic median for each location.
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