Evaluation of the Impact of Climate Change in Drought Events

Departamento de Ingeniería Civil, Universidad de Chile, Chile

Abstract: Climate Change has started to affect water resources in many ways, and it is necessary to consider the effect in future hydraulic designs. This study analyzes the consequences in four Chilean sub-basins using meteorological indexes (Standardized Precipitation Index and Palmer Drought Severity Index) and a hydrological index (Low-Flow Index) based on meteorological data from four different Global Circulation Models that force WEAP hydrological model. The results of these indexes show a sustained increase of drought events and a decrease of big precipitation events in all four basins. Particularly, assuming a stationary scenario (given by data on base line period 1975-2005) for the basin “Laja Lake” results predict that, by the end of the 21st Century, severe and extreme drought events will increase in a 10% and 20%, respectively, while, in a non-stationary scenario (given by global circulation models projected data) increases of 10% and 4% for these kind of events in the same basin are projected. Using the hydrological index, the basin “Volcan en Queltehues” is the most impacted with a large increase in average and maximum amount of days considered as drought. In this case, results indicate periods higher than 500 and 130 dry days for far future in stationary and non-stationary scenarios, respectively.