Optimum Operation of MainOutfall Drain Syphon in Dhi Qar Governorate in Water Scarcity Conditions
Keywords:Optimum operation, Pump Station, Main Outfall Drain, Syphon velocity, Syphon flashing
Descaling and cleaning of hydraulic structures are significant, which will affect on the rate of increase discharge through them.Descaling is expensive and difficult unless it depends on the operating system to avoid or reduce the occurrence of deposits.The pumping system (pumping station and syphon) located at the intersection between the Euphrates River and Main Outfall Drain in Dhi Qar Governorate suffers from the accumulation of deposits due to untreated water and its source is the outlets of sewage stations at u/s of a pumping station, in addition to the problem of shell growth in Headbasin (u/s syphon), where the shells move after sticking with a clay to the syphon area. Also, the low discharges in Main Outfall Drain trough during the dry seasons and due to climatic changes which was prevent pumping system with a design capacity,this affects on the possibility of occurrence the deposits due to the low velocity of flow. In this study, a hydraulic model was developed to increase the flow velocity to the maximum permissible using HEC-RAS 5.03 software by operating the pumping system in four scenarios under water scarcity conditions from (19-80) m3/sec for several days with closing the syphon gates. Alternating,this is increasing the flow velocity through the siphon body which helps prevent or reduce deposits in syphon body. The simulation results proved as following: Closing two syphon gates and operating the third with one or two pumps running with a discharge of 19-40 m3/sec produced a velocity of 1-2 m/sec or closing one gate and operating the others while operating three or four pumps with a discharge of 45-80 m3/sec, a velocity of discharge inside the siphon was 1.12-1.5 m/sec.
AL-Saffar, G. M. A. M., and AL-Thamiry, H. A. K., 2020. Performance Evaluation of Pump Station of Main Outfall Drain in AL Nassiriyah City. Journal of Engineering,Vol. 26 No. 9,pp. 191-203.
AL-Saffar, G. M. A. M., and AL-Thamiry,H. A. K.,2020.The effect of sediment on the syphon of Main OutFall Drain in Al Nassiriya, M.Sc. Thesis, University of Baghdad .
Brunner, Gary W,HEC-RAS River Analysis System Modeling User 'S Manual US Army Corps of Engineers HydrologicEngineering Center.
Khuzaie,H.M.A.A.,Awad, A. M., and Abbas, M. F. ,2018. A Hydraulic Model for Identification of Surface Friction Coefficient for Euphrates River within Al Muthanna Governorate, Iraq. Muthanna Journal of Engineering and Technology (MJET), Vol. 6 No.2,pp. 160-168.
Jensen.M , Tod.J and Devries.J . ,2004. Using Hec-Ras to model canal system.
Ministry of Water Resources, Directorate of the Main Drain in Thi- Qar,2019, Data of the water levels and hydraulic information of MOD, unpublished data.
Ministry of Water Resources, Main Outfall Pump Station,2019 , Data of the hydraulic information of structures and daily and annual operating rate, unpublished data.
Mohammed,A.I.Y.,Arrar,A.N.,and Abed,A.A.H.,2018.Roughness Characteristics Of Kut-Hay Reach Of The Gharraf River And Its Impact On The Hay Regulator. Association of Arab Universities Journal of Engineering Sciences, Vol. 25 No.5, , pp. 607-622.
Omran, Z. A., and Jaber, W. S. ,2017. Simulation of Sediment Transport in Al-Hilla River in Iraq Using the HEC-RAS Software. journal of kerbala university, Vol.15 No.4 , pp. 8-18.
AL-Zaidy, H.S. A., and AL-Thamiry,H.A. . ,2020. Prediction Capacity of Euphrates River at Assamawa City. Journal of Engineering, Vol.26 No.4, pp. 111-122.
Jassam, W. A., and Abed, B. S. ,2021. Hydraulic characteristics of the lower part of Diyala River.In IOPConferenceSeries: Materials Science and Engineering .Vol.1105,No.1,p. 012107. IOP Publishing.