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Sustainable Water Management -
Developing Countries |
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Projects Sustainable Water
Management and Agricultural Production in Arid and Semi-Arid
Regions Sustainable Strategies for Managing Agricultural
Water Resources in the Presence of Uncertainty (1999) New
Technologies for Assessing the Sustainability of Agriculture in
Developing Countries (2001)
Principal
Investigators MIT: D. McLaughlin ETH: W. Kinzelbach, H.
Lang, R. Kappel UT: S. Matsumoto, T. Oki Chalmers: G.
Gustafson
While there is more than enough fresh water
available on a global basis to meet the needs of the present
population, this water is not distributed evenly over time or space.
Many areas with the fastest growing populations in the world are
arid or semi-arid, and face chronic water shortages. The stress on
water resources in arid regions with large populations raises the
question of whether agricultural activities in the regions are
sustainable.
Goals/Objectives The overarching goal
of this research is to assess and promote sustainable agriculture in
a world of limited resources and growing demand. The goal of the
first research phase was to develop a method to determine whether
agricultural practices in regions are sustainable and to examine the
effectiveness of various policy options. The research had the
following specific objectives:
- To develop a general hydrologic-economic model for analyzing
the sustainability of irrigated agriculture, which can provide the
“virtual environment” to structure debates about the merits of
different policy options
- To evaluate and compare policy instruments, including command
and control regulation of water and land use, increases in water
and drainage fees, and establishment of water
markets
The research aimed at developing a dynamic and
integrated model that incorporates hydrological constraints,
economic forces and technological innovation, which could be used
universally.
The goals of the second research phase are as
follows:
- To gain a better understanding of the state of water resources
and sustainability of agricultural practices in critical
developing regions
- To show how new environmental assessment technologies can be
used to evaluate the sustainability of current water management
practices and to support the formulation of sustainable
policies
The research scope has been expanded to apply
new technologies in remote sensing, hydrology and resource economics
in a package. Cultural dimensions have also been included to assess
the effectiveness of policies designed to ensure sustainability of
water using practices. A large aquifer in North Africa has been
selected for in-depth
analysis.
Results/Findings During the first phase,
a physical-based modeling approach was developed to assess the
sustainability of current agricultural activities, and to explore
options for achieving sustainability in the future. A general
hydrologic-economic model of agriculture production and environment
quality was developed first, to examine soil and water salinization
caused by rice irrigation in the Murray-Darling River Basin of
Australia. These models were used to examine the consequences of two
land and water management policies, namely (a) restriction on the
area planted with rice on each farm, and (b) expansion of water
trading. This site was selected, as the local climate is similar to
the one found in arid and semi-arid regions in developing countries.
The analysis found that irrigated rice area would have to be
cut in half in order to stop the salinization process at present
levels. There was also evidence of a rising water table in the
region, with potentially negative effects on rice yield. The
research also found that the negative externalities of rice
agriculture may be smaller than generally believed in economic
terms. This implies that rice farmers would be sensitive to the
negative effects of irrigation because these effects have a
significant impact on their own yield. In regions where the water
table increases to unacceptable levels, rice farmers would
experience decreasing yields and probably cut back on the percentage
of land devoted to rice. If the rice restriction were lifted,
farmers with low water tables would probably grow more rice while
those with unacceptably high water tables would probably grow less.
The overall effect should be an increase in sustainable regional
revenue.
Field Studies have also been carried out in various
countries, including the Kajemaram Oasis (Nigeria), the Palapye
Aquifer (Botswana), the Iullemeden basin study (Niger), Rain
harvesting study (Thailand), and the Tarim basin water and salt
management study (China).
The first research phase generated
the following lessons learned:
- The climactic conditions and local hydrogeologic condition
have to be studied first before coming to conclusions
- It is a worthwhile to develop equitable partnerships for
mutual learning among AGS researchers and policy makers and
researchers at developed countries
- The research results need to be formulated in a manner that
can be translated into action to enable
implementation
The second phase has been based on a
case study of the “Systeme d’Aquiferes du Sahara Septentrional
(SASS)”, a large aquifer underlying portions of Algeria, Tunisia,
and Libya. The SASS aquifer is a classic common property resource.
Throughout the region, cultural and religion considerations tend to
support the view that water is too important to have its use
determined by the impersonal outcome of markets.
Significant
progress has been made in modeling the distribution of recharge
using remotely sensed data and calibration of the maps by
environmental tracers. This has worked well, particularly in the
Botswana study in Kavimba. Another important result was that digital
terrain models are not exact enough for modeling purposes. The team
has found that salinization modeling has to be coupled with ways to
account for the uncertainty of models.
AGS research has
catalyzed associated research and training support from other
sources, including Swiss Development Agency and UN agencies. The
group has also been able to make concrete policy recommendations by
working directly with the Department of Water Affairs in Botswana.
In addition, Australian researches have been using and improving the
models developed during the first research phase in their
assessments of local policy options, both in and beyond the original
study area.
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