Hydrological drought assessment over the Argentinean Andes. Links with intra-seasonal to inter-decadal climate variations.

JUAN ANTONIO RIVERA; OLGA PENALBA; DIEGO ARANEO

Santiago de Chile

Simposio; International Expert Symposium: Coping with droughts; 2014

CAZALAC, UNESCO y Flemish Government

The periods of time when streamflows are below a critical level are extreme adverse conditions that may have significant implications for society, economy and environment. In order to characterize these events at the regional level, we conducted a climatological study of hydrological droughts over the Andean rivers of Argentina. Monthly and daily streamflow data were used from 21 gauging stations distributed between latitudes 30°S and 50°S, from the San Juan River to the Santa Cruz River, with measurement periods ranging from 40 to 110 years. Two methodologies were applied at monthly and daily basis in order to depict the main characteristics of streamflow droughts and deficiencies, respectively. The Standardized runoff index (SRI) was applied to the monthly streamflow time series in order to characterize hydrological droughts during the 1961-2006 period. The SRI quantifies the number of standard deviations that the monthly streamflow on a given time scale deviates from the average value of a location during a particular period. It identifies extreme wet/dry (SRI>=2.0 / SRI