Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Main Outfall Drain and Ad Dalmaj Lake

The Hydraulic and Environmental operation for the Main Outfall Drain, Ad Dalmaj Lake and Al Hammar Marsh System

Muhannad J. Al Kazwini; Mahmoud S. Al Khafaji; Khulood J. Hussain

Engineering and Technology Journal, 2013, Volume 31, Issue 15, Pages 2816-2838

Iraqi Marshlands which are located within the southern part of Iraq were dried
after 1991. The dried marshes were re-flooded after year 2003. Because of the
shortage of water that feeds the marshes during the last years, these marshes began
to dry again. Therefore, finding new feeding sources became very necessary matter.
The Main Outfall Drain, MOD, is suggested to be one of these sources to feed Al
Hammar Marsh during the dry water years. Ad Dalmaj Lake which is located
upstream of Al Hammar Marsh is mainly feeding by the MOD water and then the
outfall of this lake is discharge again into the MOD. Therefore, the hydrological
operation of this lake and then the quantity and quality of the outflow water from
this lake into the MOD affected the water quality of Al Hammar Marsh when using
the MOD water to feed the marsh.
A hydrological and water quality routing model was prepared based on mass
conservation low, mass balance model, and two scenarios were applied for Ad
Dalmaj Lake feeding, constant inflow with variable outflow and constant outflow
with variable inflow, based on the incoming and outgoing discharges. Each
scenario includes six cases of lake maximum inundation area; 100%, 90%, 80%,
70%, 60% and minimum inundation. For each case the inundation area varied with
respect to the ET0 variation from minimum area during the month of maximum ET0
to maximum area, of this case, during the month of minimum ET0. TDS
concentration was used as a measure of the salinity of the water because it fairly
indicates the level of salinity problem. The variation of inflow and outflows
discharges, water level, lake and marsh area, storage volume, and the water salinity
within the lake and marsh were
Results of applying these models with these flow scenarios and inundation
cases show that the water salinity within Ad Dalmaj Lake and Al Hammar Marsh
was out of the acceptable range of international standards for most of the studied
cases. While for other cases it was unpalatable for drinking, several restrictions
must be imposed when used for irrigation to prevent salts effects on crops, soil, and
ground water, and not acceptable for livestock and unfit for poultry in most of the
months during two operation years and in some months in the beginning of the first
year, the water can be used for growing livestock and poultry.