Geomorphometric assessment of the river drainage network at Al-Shakak basin (Iraq)

This paper studies geomorphometric characteristics of the Al-Shakak drainage basin, which is one of the valleys of the eastern Al-Jazirah region in the eastern parts of the Misan Governorate in southern Iraq. The natural factors, which are represented by surface, geological structure, and climate, have a direct impact on forming these characteristics, such as the stream orders, stream length, mean stream length, bifurcation ratio, stream frequency, drainage density, and channel maintenance. The values of these parameters vary at the level of the main basin and the secondary basins. The total stream orders of the Al-Shakak main basin reached five orders, and their values varied at the level of the secondary basins. As for the lengths of the streams of the main Al-Shakak basin, they reached 175.607 km, most of which were in the large basins. Regarding the average length of the streams, it is measured 0.805 km at the level of the main basin, 0.766 km at the level of the first order, and 0.445 km at the level of the fourth order. The values of the river bifurcation of Al-Shakak basin 1 amount to 3.476, which is the highest value. As for Al-Shakak basin 3, it reached 1.3, which is the lowest value. In addition, the value of the stream frequency of the Al-Shakak basin amounts to 2.253 km/km2, and the drainage density reached 1.786 km/km2, with the channel maintenance being 0.561 km2/km.