Managing Scarce Water Resources in Agriculture in West Asia and North Africa - Restorative Redevelopment of Devastated Ecocultural Landscapes - page 454

commitments may change, reallocation of water can have serious legal,
equity, and other social considerations that must be addressed.
Tapping uncommitted outflows.
Improving management of existing facilities to obtain more beneficial
use from existing water supplies.
A number of policy, design, management, and institutional interven-
tions may allow for an expansion of irrigated area, increased cropping
intensity, or increased yields within the service areas.
Possible interventions are reducing delivery requirements by improved
application efficiency, water pricing, and improved allocation and dis-
tribution practices.
Reusing return flows through gravity and pump diversions to increase
irrigated area.
Adding storage facilities. Infrastructures to store and regulate the use
of uncommitted outflows, which is usually the case during wet years,
could be considered so that more water is available for release dur-
ing drier periods. Storage may take many forms including reservoir
impoundments, groundwater aquifers, small tanks, and ponds on farm-
ers' fields.
CASE STUDIES FROM THE MIDDLE EAST
s UPPlemental i irrigation. i mProves r ainfed a griCUltUre
Rainfed agriculture emerges as a potential key to sustainable development of water
and food. Rainfed agriculture produces about 60 percent of total world cereals. Future
forecasts under the Business As Usual (BAU) scenario show that rainfed agriculture
will continue to play a major role in cereal production, contributing half the total
increase in cereal production over the period between 1995 and 2025 (Rosegrant et
al. 2002). Improving water management and crop productivity in rainfed area would
significantly contribute to food security and relieve considerable pressure on water
resources.
Rainfed agriculture worldwide is practiced on approximately 80 percent of the
agricultural lands, while the remaining 20 percent is under irrigation. This rainfed
area percentage varies widely among regions: from approximately 95 percent in the
SSA tropics to 65 percent in Asia. Yield of rainfed agriculture is often low, around
1 t/ha, in semiarid tropics (Rockstrom 2001). For cereal, it is only 0.85 t/ha in the
SSA and around 1.40 t/ha in the West Asia and North Africa (WANA) region. These
numbers are way below the potential productivity. The rainfed cereal productivity in
the developed countries is about 3.17 t/ha. In China, it is 3.59 t/ha, which is higher
than the irrigated cereal productivity both in SSA (2.16 t/ha) and that in WANA (3.58
t/ha).
There is ample evidence that the low productivity of rainfed agriculture in the dry
areas of the developing countries is not only because of the vagaries of the climate
but due more to poor performance related to management aspects. Rainfed agricul-
ture in the water-scarce tropic and a large part of the dry areas is often related to the