Evaluation and analysis of changes in Khiauchai River bed at different times using cellular automai model

River bed changes, erosion and sedimentation are the natural processes of the river, each of which in turn causes the destruction of lands and huge damages to human facilities. As a developing system, the river always changes its location and morphological characteristics according to the time period, geomorphic factors, geology, water currents and sometimes due to human interventions. The purpose of this research is to evaluate and analyze the amount of changes in the Khiauchai River bed in different stages using the cellular automaton model in Ardabil province. For this purpose, the cellular automaton model was used to simulate the changes. The CAESAR model is an evolved cellular river model. In this model, for modeling, input data such as topography, daily discharge of the year (2014) and the size of river bed sediments were prepared and in the next step, channel changes were simulated. The results obtained from the cellular automaton model also showed that the morphological changes of the river bed in the cross sections of No. 22 in the second interval were equal to 1 meter. Also, the changes of the river bed in the third period of sections 44 and 60 showed 1 meter and 2 meters, respectively, and the minimum and maximum amount of changes can be seen in these sections. Therefore, based on the results, it can be concluded that the highest amount of changes in Khiauchai River bed occurred in the third period and near the residential areas. In this direction, it is suggested that human interventions should be reduced to a minimum in the third period in order to prevent the increase of river bed changes.