A Decade of Hydrological Drought in Central-Western Argentina

RIVERA, JUAN A.; OTTA, SEBASTIÁN; LAURO, CAROLINA; ZAZULIE, NATALIA

Frontiers in Water

Frontiers

Lugar: Lausanne; Año: 2021 vol. 3

Most of the water used for the development of the main socio-economic activitiesin Central-Western Argentina (CWA), an arid to semi-arid region, home to most ofthe Argentinean wine production, relies on surface streamflow from several snow-fedrivers. During the last decade (2010-2020), reduced snow accumulation over the higherelevations of the Andes mountains triggered the occurrence of hydrological drought overCWA, affecting winter tourism, restricting water use for irrigation and domestic use, andleading to socio-political disputes. This study provides a detailed description of the recenthydrological drought conditions through the use of streamflow records from 15 riverbasins, which were complemented by precipitation, snowpack, and water equivalentthickness measurements to provide a comprehensive picture of the water losses overthe last decade. Hydrological drought indices derived from the threshold level methodand the standardized streamflow index allowed characterizing the unusualness of this dryperiod in the context of the last 49 years. The hydrological deficit over the last decadehighlighted the challenges faced by the water managers to provide water for irrigation inthe main agricultural oases, with a likely overexploitation of the groundwater resourcesto supplement the limited surface runoff. The hydrological drought severity increasedsince 2017, with record-breaking levels in several basins, particularly during the periodbetween July 2019 and June 2020 for the rivers located between 35◦ and 36◦S. Weidentified themain hydrological drought impacts in CWA, as well as the need for improvedmitigation strategies to cope with current and future drought conditions. We also analyzedthe current limitations in terms of snow and groundwater observations, highlightingthe necessity for an effective hydrological drought monitoring system, together with animproved forecast of snow accumulation in the headwaters, which can contribute tobetter regional water management plans.