Variation of reference evapotranspiration in the central region of Argentina between 1941 and 2010

Study region: Changes in reference evapotranspiration (ET0) may have important consequences for agricultural suitability in the central region of Argentina. Annual ET0 variation was assessed, in terms of both territory and time, for the 7 decades between 1941 and 2010, analyzing the behavior of the 4 atmospheric variables which determine it: temperature, vapor pressure, wind speed and cloud cover. Study focus: The influence of each variable on ET0 was evaluated from a multiple regression model and a simple correlation analysis, using climate data from the observation network, and repeating this analysis using interpolated variables. In this grid scheme, linear relationships were determined between ET0 and the different key atmospheric variables, plus precipitation (PP), and the t test was applied to establish the statistically significant sectors (P < 0.1). Then, those areas with a significant trend change (P < 0.1) were determined by the Mann -Kendall test. Finally, the interception of the grids was performed to establish their joint occurrence. New hydrological insights for the region: Most of the region analyzed (>91%) presents a nonsignificant variation of ET0 over time, with a mostly non -significant change of each driving variable, regarding both its relationship with ET0 and its own trend of change. The beneficial change in agricultural suitability reported for this water -limited region was found to be produced almost exclusively by increasing PP. (C) 2015 The Authors. Published by Elsevier B.V.