Hydro-morphometric and Hydrochemical Criteria to Select the Optimal Location for Small Dam in Um Al-Shibabit Valley, Al-Shirqat, Northern Iraq

In this study, a morphometric analysis of the Um Al-Shibabit Valley basin has been done. It reflects that Um Al-Shibabit Valley is of the 7th order valley consisting of two sub-basins (northern and southern). The Valleys of two parts of the basin are linked about 6 kilometers from the Tigris River. The areal, shape, discharge, and topographic properties of the basin are determined. The area, perimeter, length, and width of the basin are 295 km², 80 km, 24 km, and 14.5 km, respectively. The shape is intermediate between circular and a rectangular basin. The discharge characteristics reveal a quick access of the downstream floods during heavy rainstorms. The hydro-chemical properties of water in the valley are studied. The chemical analyses reflect a high salinity in the upstream, near Mehha Saltern. The abundant salt in this part of the valley is sodium chloride, while the salinity decreased in the midstream to reach the lowest concentration near Ain Al-Baidha Spring. The concentration returns to increase toward the downstream, where NaCl and CaSO4.2H2O are the main salts; while in Ain Al-Baidha Spring, the main salt is CaSO4.2H2O. The water of the valley is usable for animal drinking, construction, and irrigation of crops, palm, barley, and wheat. Mineralogical and chemical diagnoses reflect that quartz, calcite, feldspar, gypsum, palygorskite, kaolinite, dolomite, and halite are the abundant minerals in the transported sediments in the valley. The optimum location selected according to the hydro-morphometric, hydro-chemical, and mineralogical conclusions is considered a location for the suggested small dam. The location is near the confluence of the two main branches of the valley. The study suggests that the separated high-salinity water at the upstream can be used for salt production and other industrial uses.