Streamflow variability and its relationship with climate indexes in western river basins of Argentina.

LAURO C.; VICH A.I.; MOREIRAS S.M.

HYDROLOGICAL SCIENCES JOURNAL-JOURNAL DES SCIENCES HYDROLOGIQUES

IAHS PRESS

Lugar: Wallingford; Año: 2019

0262-6667

Understanding changes in river flow regime of Argentinean western basins it is necessary to find out the effect of climate variability on water systems and is essential for long-term planning of water resources in complex water systems.The aim is to study the variability of the water system between 22° and 52° S. Trends and step changes of 7 hydrological variables were analyzed using non-parametric tests (Mann-Kendall, Taylor test). In addition, the link of such changes with climate variability is studied. Linear correlations between the hydrological variables and Pacific Decadal Oscillation, Pacific Sea Surface Temperature, and Southern Annular Mode index were done. Upward trends were detected in the Northwest and Central west of Argentina and downward trends in Patagonia. Streamflow of Central west and Patagonia are positive correlated with Sea Surface Temperature in the Niño 3.4 region. In addition, an inverse relationship with the Antartic Oscillation is found in watersheds south of 37°S. In the basins of North and Central west, positive step changes were detected in the mid of the 70s, while in Patagonia were identify negative changes during the 70s, 80s and 90s. These are associated with phase changes of the Pacific Decadal Oscillation.