Estimating the Minimum Amount of the Net Discharge in Shatt Al- Arab River (south of Iraq)

Abstract

This paper aims to determine the minimum amount of discharge required to maintain environmental sustainability in Shat Al-arab stream and to maintain Brackish water for the human water requirements. The study depends on the data of the water discharge and the amount of salinity in the river’s water for the periods 1994-1995 and 2010-2011. The river’s hydrological situation has changed during 2009- 2013. The tributaries feeding it with fresh water have been closed, with the exception of the Tigris river, and the discharge decreased from 724 m3/s during 1994-1995 to 44 m3/s during 2010-2011, while the water salinity at Basra station increased from 0.99 to 1.77 g/l for the two years respectively, and increased from 1.84 to 19.98 g/l at Faw station. This study shows three scenarios: that difficulty of return all the river tributaries, and difficulty to maintain the total environment on the Shatt Al- Arab stream to the Arabian Gulf, because of the huge discharge required, which is about 200 m3/s, and the difficulty of returning the water quality to fresh water. Therefore in the present time we can maintain Brackish water for agricultural and domestic uses by the area extending to Siba station. The proposed discharge amount, which would secure a reasonable amount of drinking water to the city, is about 50 m3/s, and it should be increased to 70 m3/s. in the flow times which extend for 6 days in the lunar month; besides, we should reconsider the work of Ketiban channel or instead to reimburse the amount of water it takes to the river, which is about 30 m3/s.