Geomorphic changes of the Euphrates River between Al- Raqa city and Halabiya-Zalabiyya and their impact on land use between (1943-1979) AD. Using geographic information system technologies

Abstract

The course and shape of the Euphrates River, and thus all its morphometric characteristics, change within a geomorphic-dynamic range, defined by the floodplain between the left and right edges of its banks. It is an agricultural plain, which witnessed changes in its uses with the construction of dams, land reclamation and the increase in the number of population centers. And in its geomorphic elements, such as islands and river valleys.

The research aimed to identify these changes, and it was found that the length of the river decreased by (13.8)%, as a result of the self-cutting operations of its river elbows, which led to a change in its shape from meandering - sinuosity pattern to the meandering -Anastomosing pattern. The lateral migration of the river also caused an increase in agricultural land on the right bank (Al Shameaa) due to the sedimentation process by (15) km², at the expense of the left bank (the Al Jazera), while the left bank

gained about (44.9) km², respectively, from the right bank. What caused problems and disputes between the different clans living on both banks of the river. The number of river islands (Al-Haeja) increased from (20) islands to (82) islands, due to the decrease in the amount of water in the stream after the construction of the dam, periods of drought, and the tendency of the river to sedimentation, in addition to the division of large islands with the change in the pattern of the river, which are added areas. To multiple agricultural and urban uses, its total areas reached (4.46) km² and (18.7) km², respectively. Likewise, the number of cut-off lakes, or what is known (al sarat), witnessed a continuous increase from (4) to (49) in a row, and they occupied areas of (6.5) km² and (10.4) km² respectively, which are lands acquired for the benefit of agriculture after being drained. As for the population centers, villages such as Al-Khamisiyah, Tawi, and Jadidah Kahit were completely or partially submerged, while the river moved away from other villages due to lateral migration and the truncation of river elbows, and approached other villages on the opposite bank.