The morphology of a river system is affected by dominant watershed processes including
climatic, hydrologic, hydraulic, erosion and sedimentation, geological and topographical
characteristics of the river environment and watershed. Understanding the interaction between
the river form and dominant watershed processes in river systems is necessary for recognition
of river behavior and of importance for developing river environments conceptual models.
In this research the aim was to evaluate morphological characteristics caused by dominant
watershed processes in the Firoozeh-shahjoob river of north Khorasan and extract equations in
order to mathematically link between the river physical features and watershed processes. For
this purpose, the HEC-RAS hydraulic model after doing sensitivity analysis and calibration
process was used to simulate the relation between dominant watershed processes and river
physical factors for 37 reaches of this river. Considering the standard error, level of confidence
and coefficient of determination, compared to simple linear models, second order (quadratic)
and third order (cubic) models, exponential models were the most suitable ones to extract the
mathematical relation between geometrical characteristics and the related dominant processes
in this river system.