Simple Empirical Modeling of Small Earth–Dam Break (Outflow Hydrograph)

In this work several general ideas about the earth–dam break are exposed. The two differential equations that govern the failure process are presented, constituting thus an empirical model, since the erosivity coefficient must be calibrated. For its simplicity, only the analytical solution for the case of rectangular breach of failure and nonlinear erosion is exposed. The calibration of the model and the analysis of the sensitivity of its parameters are described briefly. The empirical formulas that summarize the world–wide experience to estimate the average width of the breach, the time failure and the maximum outflow are cited. The model was applied to 97 small dams with earth embankment of the country. The results allow concluding that the exposed model is simple and physically based, and that its application to any small dam in the country only requires as input data: the embankment height and the stored volume of water before the failure. The model allows an estimate of the outflow hydrograph due to the dam breaking by overtopping flow.