Monitoring and Modelling Morphological Changes in Rivers Using RS and GIS Techniques

River geomorphological investigation issues have received little attention in most countries of the world. Such processes become a pressing necessity due to climate change and anticipated events of extraordinary surges and dry seasons, which may debilitate the security of adjacent and downstream cities, particularly in locales that are exceedingly delicate and influenced by climatic changes. Al-Abbasia reach is a river that runs through the middle of the Euphrates River and is known for its numerous bends and meanders. The study of hydraulic structures such as barrages can provide important information about their influences on morphological processes in river reaches near the barrage upstream and downstream. Hydraulic analysis is made of the river behavior in u/s and d/s of hydraulic structures like barrages as a result of sediment deposition and erosion in u/s and d/s. A study, i.e., research on the impacts of the Abbassia barrage on the river system, has been conducted to address this issue using multi-temporal Landsat satellite data from ۱۹۷۶ to ۲۰۲۲ provided by the USGS. The study reach is located ۵ kilometres upstream and ۵ kilometres downstream of the Abbassia reach. Following the construction of the barrage, which had an impact on the sedimentation and geometry of the river, morphological variations took place in this part of the Al Abbassia reach. In this study, morphological changes throughout ۴۹ years between ۱۹۷۶ and ۲۰۲۲ were investigated utilising remote sensing (RS) and geographic information system (GIS) approaches. Additionally, four image groups from three separate decades were used to perform change detection (۱۹۹۰–۲۰۰۰, ۲۰۰۰–۲۰۱۰, and ۲۰۱۰–۲۰۲۲). In this study, a monitoring system using Landsat-۳ MSS: ۱۹۸۵, Landsat-۵ TM: ۱۹۹۰, ۱۹۹۵, ۲۰۰۰, ۲۰۰۵, and Landsat-۸ OLI: ۲۰۱۰, ۲۰۱۱, ۲۰۱۵, ۲۰۲۱, ۲۰۲۲ were employed to map river planform changes. The long-term comparison of this series of satellite images and historical maps for the period ۱۹۷۶–۲۰۲۲ indicates a continuation of change in the reach study with a rate of approximately ۵۶, ۳۳, ۹۷, and ۵۵% for upstream and ۱۹%, ۲۶%, ۳%, and ۴۵% for downstream for the width, area, deposition, and erosion, respectively. Furthermore, it is observed that there is a shift in river course within ۲۰۰ m downstream of the barrage for the period of ۱۹۸۵–۱۹۹۰. The findings of this study, which monitor river morphological change at finer temporal and spatial resolutions, are crucial for promoting sustainable river management. They also aid in the investigation of river behaviour, which is necessary for providing the best management possible and overcoming the difficulties posed by this important research issue. Doi: ۱۰.۲۸۹۹۱/CEJ-۲۰۲۳-۰۹-۰۳-۰۳ Full Text: PDF

کلیدواژه ها:

Abbassia Barrage ، Landsat Images ، River Morphology ، Erosion ، Sedimentation ، Remote Sensing.