The Evaluation of Hydromorphological Conditions of Taleghan River Using MQI and RQI Methods for Environmental Planning

Rivers face many morphological and ecological changes over time, and these changes are important in environmental and development planning. The Taleghan River in Alborz Province is one of the rivers associated with many morphological and ecological changes in recent years, and for this reason, this issue has been addressed in this study. The data used in the research included library information, information obtained from Google Earth images, information obtained from field visits, as well as the 12.5 SRTM digital elevation model. Research tools also included ArcGIS and Google Earth software, as well as RQI (description and assessment of environmental conditions in riverine areas) and MQI (morphological quality index) models. This research has been carried out in two general stages. In the first stage, the environmental conditions of the studied periods have been evaluated using the RQI method, and in the second stage, the river dynamics of the periods has been investigated using the MQI model. The results obtained from RQI method have shown that intervals 1, 2, 3, 4, 5 and 6 with 46, 67, 69, 64, 44 and 43 points, respectively, have a poor status and intervals 7 and 8 They also have an average position with 74 and 76 points, respectively. Also, the results of the evaluation of the dynamic condition of the river have shown that intervals 1, 2, 3, 4 and 5 with coefficients of 0.188, 0.156, 0.156, 0.117 and 0.242, respectively. Very poor morphological dynamics, interval 6 with a coefficient of 0.453 in terms of MQI index has a weak dynamic state and also intervals 7 and 8 with a coefficient of 0.477, have the highest coefficient and in terms of geomorphological dynamics have more dynamics than the other intervals.