The role of tectonics and river network in shaping the landscapes of the Sultanate of Oman

Rivers significantly shape the Earth’s surface, responding to tectonic events while eroding and depositing sediments through various processes that transform the surrounding topography, from the watershed to the alluvial plains. The resulting landscape is a complex outcome of multiple interacting factors, including tectonics, litho-structural setting, and climate. These factors influence river networks, imparting distinct signatures on fluvial landforms and processes, and driving notable modifications in the landscape across several timescales. This study focuses on the riverscapes of the Sultanate of Oman, aiming to elucidate the evolution of the landscape and the interactions between fluvial systems and tectonic activity. The unique geodynamic framework of Oman provides a distinctive context for examining the role of river networks and tectonics in the formation of landscape. Several methods have been employed in this region, including geomorphological mapping, which combines remote sensing and field surveys to understand the main active and fossil surface processes. This mapping was further enhanced through the application of deep learning techniques to analyse the Pliocene-Pleistocene evolution of local alluvial fans, alongside geomorphometric analysis to quantify the landscape modifications. The geomorphological mapping of different areas emphasizes that the action of rivers in terms of erosional and depositional processes in the mountainous and plain regions is closely linked to tectonics and litho-structural frameworks, as well as Quaternary climatic fluctuations. The integration of deep learning and geomorphometric techniques provides objective methods to quantify the role of litho-structural setting and the effects of changes in riverine agency on the landscape. Specifically, deep learning enhances the detection and accuracy of fluvial landforms on satellite imagery, shedding light on past hydrological conditions and illustrating the climatic and tectonic influences on the evolution of alluvial fans at the foothills of mountain belts. Concurrently, geomorphometry quantifies landscape variations through topographic and river network analysis, permitting the detection of portions of the landscape in disequilibrium with ancient stable surfaces. This reveals that the current landscape is still in a state of evolution, indicative of ongoing geodynamic processes. The integration of geomorphological mapping, deep learning and geomorphometry provides a comprehensive understanding of the complex interactions within the river network, allowing for the quantification of the role of both regional tectonic processes and local structural settings in shaping the landscapes of the Sultanate of Oman.