Document Type : Review Article
Authors
1
Department of Geomorphology, Faculty of Geography and Environmental Sciences, Hakim Sabzevari University, Sabzevar, Iran
2
Department of Natural Geography, Faculty of Remote Sensing and GIS, Esfahan University, Esfahan, Iran
Abstract
Riverine systems are of significant morphological importance due to their key role in the management and protection of floodplains. This study aims to evaluate the morphological changes and management of the Kal-e Shur River in Sabzevar using the Rasgen classification system. Initially, morphometric parameters were calculated using HEC-RAS software, and 419 cross-sections across 40 river reaches were extracted from satellite imagery. Sediment samples were collected from the riverbed to characterize the local sediment types. Nineteen geomorphological parameters were analyzed, and the most influential factors controlling river type were identified using the Information Gain Ratio (IGR) index. Results indicated that land use, precipitation, elevation, soil type, drainage density, vegetation cover index (NDVI), lithology, topographic slope, distance from the channel, topographic wetness index (TWI), and sediment transport index (STI) exerted the greatest influence. Segments classified as type D, with gentle slopes and sandy beds, exhibited poor conditions regarding sediment supply and erosion, although vegetation cover in these areas remained relatively preserved. Type C reaches were characterized by significant channel incision and high potential for erosion and flooding. In type B rivers, changes in flow patterns and sediment input contributed to channel instability. Conversely, type A, E, and G segments showed stable beds, lower sensitivity to turbulence, and better-preserved vegetation cover. These findings demonstrate that the Rasgen classification aligns well with geomorphological and morphometric factors, supporting its application in river management, restoration, and the mitigation of erosion, sedimentation, and flood hazards.
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