Water accounting for the Urmia Lake Basin was carried out for two water years of Oct 2013- Sep 2014 and Oct 2014 – Sep 2015. The accounting period corresponds with the Iranian water years of 1392-03 and 1393-94. WA+ sheet 1 and 2 was prepared for the i) Urmia Lake Basin area that excludes the Lake and the surrounding salt desert, ii) Cluster of three sub-basins located in the south of the Lake (Zarineh-roud, Simineh-roud and Leylan Chai) and iii) Aji Chai Sub basin. In this section we will present the WA+ results for these areas separately.
The focus area for the basin level analysis was the whole Urmia Lake Basin minus the lake and its surrounding salt desert. The total outflow from this area was considered as the total inflow to the Lake. Figure 1 shows the area that was covered in the basin level analysis, which covers 44,403 km2 and consist of 22 sub-basins. The annual average rainfall in the accounting period was 310 mm and 369 mm in the water years of 2013-14 and 2104-15 respectively.
Figure 2 shows the WA+ resource bases sheet for Urmia basin in the 2013-14 accounting year (hereafter year 1) and 2014-2015 (hereafter year 2). The unit used in the sheets is 0.1 km3 to avoid rounding being volumes of water in the presentation of the results. The total precipitation was 13.76 km3 (=137.6 x 0.1 km3) in the year 1 of which an estimated 2.7 km3 was recycled from the evapotranspiration in the basin. The year 1 with an average precipitation of 310 mm was considered as a dry year when compared to long term basin average of 378 mm (Moradi et al., 2017). The year 2 with a precipitation of 369 mm was closer to an average year.
Figure 3 shows the WA+ Evapotranspiration sheet for the Urmia Lake basin in year 1 and 2. The ET sheet primarily designed to provide information on the processes through which water is consumed. The results show that in Urmia basin on average 40% of the total ET is originated from human managed processes. In the year 1, of the total 13.46 km3 (=134.6 x 0.1 km3) evapotranspiration 5.57 km3 (=55.7 x 0.1 km3), 41%, has been through managed activities. In the year 2, of the total ET of 15.42 km3 (=154.2 x 0.1 km3), 6.13 km3 (=61.3 x 0.1 km3) was managed. In both years agriculture was the primary consumer of water within the managed activities. Agriculture, combined for both rainfed and irrigated, accounts for 31% of the basin total ET. A significant portion, 42%, of evapotranspiration from agriculture is through rainfed agriculture and the rest 58% is through irrigated agriculture. Almost half, 50%, of water consumed in rainfed agriculture is lost to evaporation.
This section presents the WA+ resource base sheet and Evapotranspiration sheet for Aji Chai and a cluster of three sub-basin of Zarinehroud, Siminehroud and Leylan Chai (Figure 4). The input data used and the process applied are similar to those used for Urmia basin and are explained in Chapter 3 of this report. Similar to Urmia basin accounting was carried out for two water years of Oct 2013- Sep 2014 (Year 1) and Oct 2014 – Sep 2015 (Year 2). The values in sheets presented below are in 0.1 km3.
Aji Chai is located in the easten side of the Urmia Basin and it encompases Tabriz city which is the both largest and mpst populated city in the basin. Aji chai covers and area of 10770 Sq.km and receives an annual rainfall of 307 mm in year 1 and 347 mm in year 2. Aji chai recives an annual flow of nearly 0.14 km3 (= 1.4 x 0.1 km3) through a water transfer project from the Norolozlou diversion dam in Zarinehroud sub-basin. This water is shown in the resouse base sheet as Qswin in both year 1 and year 2 of the water accounting analysis. Similar to the approach in Urmia basin WA+ appliction, entire outflow was considered as reserved flow in both years. Figure 5 and 6 shows the resource base sheet and evapotranspiration sheets for Aji Chai sub-basin respectively.
These three sub-basin all located in the southern part of the Urmia basin are considered as one big sub-basin for conducting WA+. The reason is that the three sub-basin are connected through a network of canals and drains in the Miandoab irrigation scheme. In addition they share the Miandoab aquifer which is actively used for irrigation in the Miandoab scheme. These facts make the three sub-basins hydrologically inseparable in the absence of measured figures for both surface water distribution and groundwater use and recharge. The cluster is spread over 16970 Sq.km of land area, equal to 33% of the whole basin area including the Urmia Lake. Some 0.14 km3 (= 1.4 x 0.1 km3) is exported to Aji cahi annually which is shown in the resource base sheet undet Qswout. Similar to the approach in Urmia basin WA+ appliction, entire outflow was considered as reserved flow in both years. Figure 7 and 8 shows the resource base sheet and evapotranspiration sheets for Southern 3 sub-basins respectively.