1 research outputs found
Cascading Overtopping-Induced Dam Failures in a Transboundary Basin: Hydrodynamic Modeling from Gawshan to Darbandikhan Dam
No full textThis study investigates the cascading failure potential of a multi-dam system in the transboundary Diyala (Sirwan) River basin, spanning Iran and Iraq. Using a two-dimensional hydrodynamic model developed in Hydrologic Engineering Center’s River Analysis System 6.6, the study simulates overtopping- and piping-induced breach scenarios at Gawshan Dam and assesses their propagation through downstream reservoirs including Zhave, Daryan, and Hirwa, culminating at Darbandikhan Dam. The results highlight the formation of a compound flood wave that exceeds crest elevations, particularly under overtopping scenarios, leading to overtopping failure at Darbandikhan Dam despite emergency discharge operations. Scenario 1, representing full reservoir conditions and sequential overtopping failure, was identified as the most severe. The model outputs show a rise in water surface elevation from 485.0 m to 495.5 m within 412 min at Darbandikhan Reservoir, causing structural overtopping. Extensive inundation impacts both Iranian upstream settlements and Iraqi downstream communities, submerging over 20 villages and 80 km2 of agricultural land. The findings underline the need for transboundary coordination, reservoir reoperation protocols, and updated Emergency Action Plans to mitigate the risk of cascading dam failures in seismically active regions
