Document Type : Research Article
Mousa Abedini*, professor of Geomorphology, University of Mohaghegh Ardabili, Ardabili, Iran
Ph.D. student, Department of physical Geography, Mohaghegh Ardabili University, Ardabil, Iran
River channel changes, bank erosion and bank sedimentation are natural processes of alluvial rivers that cause destruction of surrounding agricultural lands and damage to human facilities around the river. In this research, Rasgen model (level 1, level 2 and level 3) has been used to evaluate the condition of Darehroud river in order to measure the amount of bank erosion, and level 1 has been used to determine the type of channel after obtaining the slope of Darehroud river in the studied area. According to the slopes obtained from different sections and field observations of the cross-section and plan of the river in field studies and taking into account the classification of rivers based on different slopes in the initial classification and level 1 of Rasgen, the sections in question were placed in group B and A. In this research, 6 sections from Gavlan village to Laqan village with a length of 5 km have been selected. After determining the classification of the river in the first and second level of Rasgen, the conditions of Darehroud river and its intervals, from the total points obtained in the third level of Rasgen, from the total points obtained in the third level of Rasgen, in the studied area, intervals 2 and 5 And 6, all three of the 4B brigade group, with the total points of 91, 85, and 111, respectively, and the 4A brigade group with 87 points, are in a weak and unstable situation. Sections 1 and 3 of type 4A are in a good and stable condition with total points of 91 and 87, respectively. In fact, the classification of Darehroud river in the studied area based on Rasgen level one, two and three classification system is a logical assessment that provides more accurate information for management applications.