climate change on UAE - Stockholm Environment Institute-US Center

water to meet its demands, Unmet Demand for
this sector can be thought of as “additional
desalinization capacity needed”. For the
forestry and agriculture sector that rely on
groundwater, “unmet demand” suggests the
non-sustainability of the water use activity and/
or the overdrafting of groundwater aquifers.
For the analysis of water supply, we will focus
on the Optimistic with Adaptation (1.1) and
the Pessimistic with Adaptation (2.1), where
both include their respective <strong>climate</strong> <strong>change</strong>
forcing. From this analysis, it is very apparent
that unless future per-capita water use is not
substantially curtailed, future demands will
only be met through increased desalinization
capacity, while the agriculture and forestry
sectors would increasingly need to turn to
more saline groundwater to meet irrigation
requirements. Renewable freshwater resources
in the eastern portion of the ADE are simply
not substantial enough to be considered a
major contributor to the future water resource
portfolio on the ADE.
In Figure 5-3, desalinzed water supply grows
up to its currently installed capacity but then
capacity does not <strong>change</strong> over study horizon.
Fresh groundwater resources remain constant.
To continue to support irrigated agriculture
where brackish groundwater sources are
inadequate, irrigation requirements are madeup
through pumping of saline groundwater
supplies. Fresh groundwater supplies remain
nearly constant, as they have been constrained
to make up only 10% of the total groundwater
supply in WEAP, otherwise the alluvial,
freshwater aquifers in the western portion of
the ADE would be quickly overdrafted. Once
this 10% of demand is met through the fresh
groundwater resource, brackish and then saline
groundwater sources can supply the remaining
irrigation needs.
WEAP assumes that all sources can adequately
supply crop water requirements, as WEAP
makes no distinction between water supply type,
except the distinction of preference from which
supply to draw from first (e.g. first brackish
and if there is an inadequate supply, then draw
from the saline groundwater). The supply
allocation for the Pessimistic with Adaptation
(2.1) Scenario is nearly identical to Scenario 1.1
because we have constrained supply to current
levels (e.g. no <strong>change</strong> in desalinized water or
waste water treatment expansion).
Figure 5.4 shows the estimated unmet demands
Total Unmet Demand
Figure ‎5‐4. Total unmet demand for the Optimistic and Pessimistic Scenarios with Adaptation.
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Climate Change Impacts, Vulnerability & Adaptation