Overtopping Breach of Cascade Earth-Rock Dams – State of the Art Review

Once a dam in a cascade reservoir group fails, it can easily trigger a “domino effect”, leading to successive breach of downstream dams, causing catastrophic consequences for people’s lives, property, and the ecological environment. This paper aims to review the current research status of dam breach of cascade earth-rock dams. First, the development status and spatial distribution characteristics of cascade reservoirs are expounded, and the typical cases of cascade earth-rock dams breach are reviewed and analyzed. Second, the latest progress of dam-break flood routing simulation methods are summarized. Three typical evolution patterns of dam-break flood in the downstream reservoir area are identified, and the influence of different factors on the water body climbing height and dam surface pressure in front of the dam is discussed. Based on domestic and international cascade dams breach model tests, the problems existing in the design of breach model tests are pointed out. From the perspective of mass and energy conversion, the internal mechanism of flood peak enhancement effect is discussed, and the distribution characteristics of inflow discharge and velocity when dam-break flood enters the downstream reservoir area are revealed and equivalently quantified. Finally, the latest progress in the simulation method of cascade earth-rock dams breach is discussed, the uncertainties and limitations of the current models are evaluated, and suggestions for the future development of mathematical models are put forward.