Geomorphological Hazards and Their Environmental Impacts in the Tigris River Valley between the Zones of Al-Zweih and Al-Fatha

Abstract

This study examines the geomorphological hazards of the Tigris River Valley in the area extending from Al-Zweih to Al-Fatha within Salah al-Din Governorate. The research focuses on floods, changes in the river course, river islands, and their environmental impacts. The results show that areas classified as high-risk constitute approximately 17.7% to 28.4% of the valley's area at water levels ranging from 1 to 4 meters. These areas are located very close to the river course and are subject to seasonal inundation. Medium-risk areas cover between 6.1% and 45.2% at the same water levels and include most of the modern floodplain and surrounding villages. Low-risk areas represent the elevated lands near the old floodplain, which are suitable for settlement, accounting for 6.4% to 46.2%.

The study also reveals significant changes in the Tigris River course during the period from 1985 to 2024. The river’s surface area decreased from 42.145 km² to 29.134 km². Additionally, the number of river islands declined markedly from 36 islands to 12 islands, accompanied by a reduction in the total area of these islands from 11.18 million m² to 6.558 million m². These transformations reflect the influence of several natural factors, such as climatic and hydrological changes, in addition to human activities, including agricultural and construction expansion, which collectively contributed to reshaping the river course and sediment distribution.

The study recommends a set of solutions to address the high-risk areas, including the construction of earthen dams at critical locations, reinforcement of riverbanks using erosion-resistant rocky materials, enhancement of river course monitoring systems, and the regulation of land use near the river. These measures aim to mitigate the negative environmental impacts caused by both human interventions and natural factors