Evaluation of the performance of river hydraulic structures during floods using RIAM and MLM methods

The performance of hydraulic structures and river engineering operations performed in urban areas have a great importance and role in flood control-management and reduction of human and financial losses. The flood of March 18, 2019, in northern Iran is an example of terrible and damaging floods in the history of recorded flood events in Iran. In this study, using satellite information, field data, rapid impact assessment matrix (RIAM), and modified Leopold matrix (MLM), the most important negative consequences of floods in terms of erosion and sediment on hydraulic structures located on the Tajan River, Sari city, were evaluated. The results showed that both studied matrices and field observations emphasize the more destructive impacts of erosion compared to sedimentation. The results of the RIAM and MLM methods indicated that the most important negative consequence of erosion was related to local erosion with the values of − 267% and − 417%, respectively. According to the results of the RIAM method, the impact value of the general sedimentation as the most important negative consequence was equal to − 222%. The results of the MLM method reflected that the amount of negative impact in terms of local or generality was equal to − 367%. Also, in terms of sedimentation, the results of the RIAM method are closer to the reality. Conducting structural performance evaluation studies in the face of severe floods with high return periods makes it possible for managers and politicians to identify the most important negative consequences of floods on hydraulic structures. Graphical abstract