Numerical assessment of Karun river infuence on salinity intrusion in the Shatt Al‑Arab river estuary, northwest of Arabian Gulf

Abstract

The influence of Karun river inflow on salinity intrusion from the Arabian Gulf towards the upper reaches of the Shatt Al-Arab river estuary was evaluated by using Mike11, a one-dimensional numerical modeling technique. The simulations results indicated that, during the moderate and low flow conditions of the Shatt Al-Arab river, freshwater inflow from Karun river at 10 and 40 m3/s, respectively, could be capable of keeping salinity extent to not exceeded the confluence location of these two rivers. Additionally, the results indicated that in the case of a sharp decline of Karun river inflow, additional releasing of freshwater from the Tigris river can completely compensate for the Karun inflow. While in the case of cut off of Tigris river, the Karun inflow in the range of 60 m3/s could be able to keep salinity extent beyond the Abo Flous station during the simulation period. Furthermore, the possibility of discharging water with high levels of salinity from the farming projects located at the lower basin of Karun river towards the Shatt Al-Arab river estuary was taken into account. In such cases, the results suggested that during low and moderate flow conditions, freshwater inflow by about 250 and 225 m3/s, respectively, should be released from the Karun river to remains salinity extent below the Abo Flous location. A water management policy agreement between Iraq and Iran could be an effective solution to the salinity issue both in the Shatt Al-Arab river estuary as well as Karun river.