Nature of the Distributed of the Bed Sediment within Mosul Dam Reservoir, Iraq

Nature of the Distributed of the Bed Sediment within Mosul DamReservoir, IraqNadhir Al-Ansari Issa E. Issa Sven Knutsson[emailprotected] [emailprotected] [emailprotected]Lulea University of Technology, SwedenAbstractMosul Dam is one of the biggest hydraulic structures in Iraq. It was constructed in 1986on the Tigris River in the north of Iraq. The initial storage capacity and water surfacearea of its reservoir reaches 11.11 km3 and 380 km2 respectively at the maximumoperation level 330 m a.s.l. The dam was operated in 1986. A total of 56 samples werecollected from the bottom of Mosul reservoir covering most of the reservoir area. Theresults of the analysis of these samples revealed that they were composed of gravel(3.8%), sand (15%), silt (55.5%) and clay (25.7%). The distribution of these sedimentsindicates that the silt portion represents the highest followed by clay and then sand.However, sand percentages are the highest in the northern zone of the reservoir wherethe River Tigris enters the reservoir and decreases gradually toward the dam site. In themeantime, silt percentage decreases toward the dam site while the finer fraction (i.e.clay) increases.Keywords.Mosul dam, reservoir sedimentation, sediment size distribution, sedimentcharacteristics. - / / / 6891 . 66.66 3 393 2 333 . . % 3.8 % 15 55.5% % 25.7 .