Failure of dams arranged in series or in complex

peer reviewedA practical methodology has been developed for predicting flows generated by dam failures or malfunctions in a complex or a series of dams. A twofold approach is followed. First, the waves induced in the downstream reservoirs are computed, as well as hydrodynamic impacts induced on downstream dams and dikes are estimated. Second, the flood wave propagation and the inundation process are simulated in the downstream valley, accounting for possible dam collapse or breaching in cascade. Two complementary flow models are combined: a two-dimensional fully dynamic model and a simplified lumped model. At each stage, the methodology provides guidelines to select the most appropriate model for efficiently computing the induced flows. Both models handle parametric modeling of gradual dam breaching. The procedure also incorporates prediction of breach formation time and final width, as well as sensitivity analysis to compensate for the high uncertainties remaining in the estimation of breach parameters. The applicability of the modeling procedure is demonstrated for a case study involving a 70m-high gravity concrete dam located upstream of four other dams