climate change on UAE - Stockholm Environment Institute-US Center

Table 4-5. Comparison of Historical Estimated and WEAP Modeled Demands.
2003
Obs
Est.
East (Mm 3 ) West (Mm 3 ) TOTAL (Mm 3 )
Model Obs Est. Model Obs Est. Model
M&I 152 152 428 320 580 472
Agriculture 1109 1200 840 770 1949 1970
Forestry 123 115 484 445 607 560
Amenity 111 114 134 134 245 248
TOTAL 1495 1581 1887 1669 3381 3250
2005
Obs
Est.
East (Mm 3 ) West (Mm 3 ) TOTAL (Mm 3 )
Model
Obs
Est.
Model Obs Est. Model
M&I 111 170 641 351 752 521
Impacts, Vulnerability & Adaptation for
Water Resources in Abu Dhabi
Agriculture 980 1230 760 750 1740 1980
*Forestry 125 115 237 488 363 603
Amenity 118 124 137 154 255 278
TOTAL 1334 1639 1775 1743 3109 3382
*The Environment Agency of Abu Dhabi reports a substantial reduction in forestry in the ‘Uo El Dabsa Plantation’ in 2005.
mostly to the down-scaling of the Uo El Dabsa
plantation”, which we did not assume.
The allocation algorithm in WEAP automatically
allocates water supplies to the various demands,
with results of that allocation from the 5 year
simulation (2002 through 2006) summarized in
Figure ‎4‐5 and Figure ‎4‐6.
Figure ‎4‐5 shows the WEAP estimate of total
annual demand for the agriculture, amenity,
forestry, and M&I demands for the years 2002
through 2006. This simulation assumes that
the M&I demands increase only due to the
growing population, as per-capita demands
were fixed over the simulation period. For the
agriculture, forestry and amenity demands, it
was assumed that the cropping pattern and
cropped area did not <strong>change</strong>, thus the yearto-year
variability are only due to climatic
variability. The figure includes the total
annual potential evaporative demand for
these two years to illustrate the magnitude
of the climatically forced fluctuation of PET.
There is a strong correlation between PET
and the sectoral demand.
Figure 4-6 shows that WEAP allocated about
78% of the total delivered water supply from
brackish groundwater sources, 3% from fresh
groundwater, and 13% from desalinized water,
while reused water made up about 6% of the
total supply. These results are fairly consistent
with the supply make-up shown in Table 2.1. It
is important to realize that the WEAP allocation
algorithm is making the allocation “decision”
from the various supply sources to the demand
sites based on demand priorities and supply
preferences made a-priori.
The WEAP-based, climatically driven water
resources model of the ADE adequately reflects
the spatially and temporally specific water
supplies and demands. This model was used
to simulate future water demands and supplies
based on Scenarios and assumptions about
future <strong>climate</strong>, population growth, per-capita
water use, and sectoral demands. The Scenarios,
assumptions, and results are described below.
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