Interannual-to-multidecadal hydroclimate variability and its sectoral impacts in northeastern Argentina

Interannual-to-multidecadal hydroclimate variability and its sectoral impacts in northeastern Argentina

M. A. Lovino, M. A. Lovino, O. V. Müller, O. V. Müller, G. V. Müller, G. V. Müller, L. C. Sgroi, W. E. Baethgen

This study examines the joint variability of precipitation, river streamflowand temperature over northeastern Argentina; advances the understanding oftheir links with global SST forcing; and discusses their impacts on waterresources, agriculture and human settlements. The leading patterns ofvariability, and their nonlinear trends and cycles are identified by means of aprincipal component analysis (PCA) complemented with a singular spectrumanalysis (SSA). Interannual hydroclimatic variability centers on two broadfrequency bands: one of 2.5–6.5 years corresponding to El Niño SouthernOscillation (ENSO) periodicities and the second of about 9 years. The higherfrequencies of the precipitation variability (2.5–4 years) favored extremeevents after 2000, even during moderate extreme phases of the ENSO. Minimumtemperature is correlated with ENSO with a main frequency close to 3 years.Maximum temperature time series correlate well with SST variability over theSouth Atlantic, Indian and Pacific oceans with a 9-year frequency.Interdecadal variability is characterized by low-frequency trends andmultidecadal oscillations that have induced a transition from dryer andcooler climate to wetter and warmer decades starting in the mid-twentiethcentury. The Paraná River streamflow is influenced by North and SouthAtlantic SSTs with bidecadal periodicities.The hydroclimate variability at all timescales had significant sectoralimpacts. Frequent wet events between 1970 and 2005 favored floods thataffected agricultural and livestock productivity and forced populationdisplacements. On the other hand, agricultural droughts resulted in soilmoisture deficits that affected crops at critical growth stages.Hydrological droughts affected surface water resources, causing water andfood scarcity and stressing the capacity for hydropower generation. Lastly,increases in minimum temperature reduced wheat and barley yields.

2018

10.5194/hess-22-3155-2018

Hydrology and Earth System Sciences

Copernicus Publications

Geography. Anthropology. Recreation, Environmental sciences, Technology, Environmental technology. Sanitary engineering