تطور الالتواءات والمنعطفات النهرية في مجرى نهر دجلة في ناحية القيارة

Abstract

The study aimed to study the torsions of the river section in the Qayara area, and to identify the factors and processes affecting the evolution and development of these curves and turns, as well as to detect the development of spikes and turns. The study area is the scene of numerous river processes that formed many different geomorphic features, including torsions and river turns resulting from the destructive and structural processes of the river. The study concluded that one of the natural causes in the formation, development and development of torsions and river turns is increasing the amount of drainage, The convex side, as well as human factors The spread of quarries in the region contributed to the formation of torsions and turns of the river, and to monitor the geomorphic changes occurring in the Tigris River during different time periods relied on the (60 x 60 m) with a resolution of spatial discrimination for the first years of 1973, for the absence of a higher resolution of this year, which was chosen before the construction of the Mosul Dam, and the second satellite of (Landsat 4 -TM) and the third satellite in 2017 (Landsat8). The spatial accuracy of the last two mirrors was (30X30) meters. The pattern of the course of the Tigris River, which appears in the space visuals in dark black, represents a clear line separating the course of the river and its surroundings from the land after we used the Third Band for the vision of 1973 and the Fifth Band for the vision of 1992 and the Seventh Band for the vision of 2017. To highlight the morphological and geomorphic characteristics Of the curves and turns of the river through the comparison of the visuals of different periods and then give a clear picture of the nature of the processes experienced by the torsions and turns of the river and the resulting evolution in its dimensions and morphology.