Analysis of Meanders and Bends of Lesser Zab River from Dalga VViilllage to Darbandi Rania

Abstract

This study investigates the meanders of the Lesser Zab River in the study area, in terms of morphometric characteristics such as )length, width, direction, shape, area and symmetry of the meanders( and their distribution along the main river in the river valley through explaining the forcing factors in the creation of such shapes such as slope, geological structure, transported materials, flow of tributaries into the main river and tectonic activity in terms of geomorphic actions such as (carving, removal, transportation and sedimentation(, with the influence of human factors. Also, the phases of meanders development from north to south in the river valley are discussed. Furthermore, differences and dissimilarities of such formation can be seen between the periods 1972-2021; this is reflected in morphometric characteristics and geomorphic actions in all parts of the river basin. This research relies on various research methods such as deductive method, numerical methods and cartographic methods; using (ArcGIS.version.10.8), with the use of digital elevation model (DEM12.5m), to conduct detailed field work by the researcher. In the study area, 17 bends and meanders in the river have been identified, of which 7 bends were bends and 10 were meandering with the percent of meandering reaching (1.58), and the bend of Kewiya has the highest rate of twist, which reached (5.4). At the same time, the value of symmetry in the bend of Bekhre village is completely symmetric, because the value of each side (X) and (Y) is 49. For example, the length of the river for each of the years (2020,1984 and 2021) consecutively reached (32 km, 32.876 km, 31.7٢7 km), These changes will affect the size of human activities in the study area such as )distribution of human settlements, agricultural activities, poultry farms, fish ponds and industrial activities).