Morphometric characterization of del Molle Basin applied to the evaluation of flash floods hazard, Iglesia Department, San Juan, Argentina

PERUCCA, L. P. AND ESPER ANGILLIERI, M. Y

QUATERNARY INTERNATIONAL

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2010 vol. 233 p. 81 - 86

1040-6182

One of the main geological hazards that affect the Iglesia department is flash floods, producedby heavy seasonal rains, characterized by their high velocities and destructive power. Thesestreams are generated in the watersheds of the mountainous region of the Cordillera Frontal.The del Molle basin was selected as a suitable case to evaluate the potential magnitude offlash floods in relation to their associated hazard level in Malimán de Arriba, located directlyat the confluence of the tributaries with the Blanco River. This paper evaluates some of thehydrological aspects of a torrential regime basin that caused severe damage in Malimánduring January 2010.This work analyzes different morphometric characteristics of the El Molle basin in order toevaluate the flash flood hazard. For this purpose, the basin is divided into four sub-basins andsome basic parameters (surface, perimeter, basin length, elevations and slope of the main riverbed) are calculated. These parameters allow approximate prediction of the behavior of thebasin in the presence of a series of theoretical rainstorms which may generate unusual runoffvolumes. The predicted flash floods were compared against the Malimán flash flood.