Predicting of changes in stream path and morphology of Gorganrood river with emphasis on flooding

In recent years, the occurrence of several destructive floods in the southeastern plain of the Caspian Sea, caused by the flood of the Gorganrood River, has caused many casualties and damage. Predicting the future morphological conditions of the river and its surroundings is one of the essential factors in planning and arranging the coastal plains. In this research, Landsat 5, 7, and 8 satellite images of 1987, 2002, and 2018, with field studies, software studies, and CA Markov automated cells model were used as research materials. The accuracy of the modeling was confirmed using random ground control points. Also, the reaction of the river canal at the flood events was examined based on the satellite image of April 3, 2019. The results showed that the most probable changes in the study area are in river, plains, and man-made facilities units around Voshmgir Dam Lake. Also, the very low hydraulic slope of Gorganrood in the downstream areas of Voshmigir Dam prevents the rapid evacuation of floods and creates a reverse flow and flooding of the surrounding lands. This phenomenon causes the Gorganrood flood and Qarasoo tributaries to interfere in the area between Salagh-Yelghi and Aq Qala. Therefore, increasing the height level of the river shores between the tributaries of Gorganrood and Qarasoo can prevent the flow of interference in them and reduce the risk of flooding of the Qarasoo around lands. Due to water flooding and flood transmission through abandoned canals of Gorganrood in the northern lands of Aq Qala to Siminshahr, the construction of an emergency flood drainage canal through abandoned canals can be a permanent solution to control floods in these areas.