Susceptibility to flooding for torrential flows using the integration of the geomorphological method and the modelling with FLO-2D, lake Atitlan, Guatemala

Lake Atitlan (Guatemala) is located in the transit region of the tropical cyclones formed in both the Atlantic Ocean and the Pacific Ocean. Every year, these phenomena cause abundant and intensive rain fall which in turn provokes floods associated with the formation of destructive flows. This paper aims to deepen the knowledge of such processes and the prediction of their spatial distribution. The work was carried out in the Tzununa basin, taking as reference phenomena Hurricane Stan (2005) and Tropical Storm Agatha (2010). When they passed through the region, maximum rain falls of 383 and 269 mm were registered on two consecutive days. In this work, the geomorphological method was developed and flows were simulated with different rheological properties using FLO-2D software. The geomorphological detailed exploration field work has been essential and has allowed the validation of some of the model results. It has also enabled us to discard others wich are not representative of real conditions. The integration of the results of both methodologies has made possible the creation of a more detailed and validated inundation susceptibility map.