The morphometric characteristic of the basin of Bandawaya valley

Abstract

The study aims to analyse the morphometric characteristics of the Bandawaya Valley Basin, represented by the spatial, longitudinal, morphological and topographic characteristics, and the characteristics of the drainage network. The Bandawa Valley River is one of the branches that flow into the Tigris River. The basin of this river is located between three districts, which are (Dohuk, Shekhan, and Simele), and a section of it is located in the (Nineveh) Governorate. In the north of the basin is Mount (Zawa), and in the east of the basin is Mount (Brifka), and in the west of the basin is the (Sharia) plain, while in the south is the (Bibouzi) plain. The area of the Bandawa Valley Basin is (151) square kilometres, and the length of the Bandawa Valley Basin is estimated at about (29,872) kilometres, and the width of the Bandawa Valley is (5,054). The study relied on geographic information systems(GIS), topographic maps and the digital elevation model(DEM) of the region with an accuracy of (12.5) as a tool for preparing a river drainage network map, which was classified according to The Strahler method (1958) gives a numerical order to the tributaries that form the drainage network. The study highlighted the presence of (six) river ranks for the basin, the number of waterways (1789) with a length of (535.52) km. The Bandawaia Valley basin has two patterns of water drainage, the first (tree pattern) and the second (parallel pattern). The topographical texture of the basin reached (19.61) streams/km. It has a smooth texture and increases the amount of water flow. The shape of the basin is close to the rectangular shape, as the elongation ratio in the Bandawaia basin reached (0.46). This indicates that the shape of the basin is far from the circular shape. This is a result of the change in the width of the water basin from the source to the outlet, with a curvature factor of (1.5) due to the structural and topographical effect of the region. The numerical drainage density in this basin is (11.8) streams/km. This indicates an increase in the surface water drainage in the basin, as the basin is characterized by a high degree of ruggedness and a ratio of the relief reached (34.34) meters/km. The water source for the Bandawaia Valley basin consists of three springs, the first of which is called (Tantour), the second (Shir and Malkta), and the third (Sakra Akhl Marmikha). The water of this basin continues to be discharged throughout the year, and in the winter the water level reaches two meters.