Assessment of Natural Hazards and Vulnerability in the Rio Copiapó Catchment: A case study in the ungauged Quebrada Cinchado Catchment

Abstract

Intensive precipitations in desert areas are a very scarce phenomenon. Nevertheless, from time to time these events take place, as in 1997 in Southern Atacama Desert in Chile. The study area within the Copiapó catchment is intensively exploited by mining activities. However, in recent years the landscape has been more and more used for agricultural purposes. Vineyards for grape production are irrigated with water from the Copiapó River and from groundwater aquifers. The agricultural activity is mainly focusing on the flat valley bottoms, as well as drainage lines that become active in cases of precipitation events. Thus, this study seeks to investigate the geo-hazards related to precipitation events in order to quantify the risk for population and agricultural areas. Therefore, this study applies a hydrological model calibrated in the ungauged basin of Quebrada Cinchado. The results demonstrate that events like the one on the 12.06.1997 generate intensive floods and related sediment discharges that endanger population and agricultural areas. The applied methodology allows quantification of flooding and mudflow risks, as well as to assess the spatial distribution of geo-hazards.