Recent and historic Andean snowpack and streamflow variations and vulnerability to water shortages in central Chile and central-western Argentina.

MASIOKAS, M.H.; VILLALBA, R.; BETMAN, ERNESTO; CHRISTIE, D.

Tilcara

Encuentro; IAI Collaborative Research Network 2047, Final Science Meeting; 2011

Inter-American Institute for Global Change Research

The original idea of this Project was to reconstruct Andean snowpack using precipitation sensitive tree-ring series. However, we found there were very few analyses of instrumental snowpack data for this portion of the Andes. So we started compiling data and developed regional snowpack andstreamflow series and then assessed the main temporal variations of these regional records.Regional snowpack and annual streamflow records show striking similarities that highlight the strong common hydrologic signal in this region and the good quality of the original data.The highest concentration of extreme dry (wet) conditions occurred between 1954 and 1971 (1977 and 1987)Data from the main rivers in Mendoza indicate water needs in the oases are higher than the volumes provided by surface runoff in normal years Improving efficiency can help reduce vulnerability to the highly variable water regimes in the region Groundwater is crucial in all river basins, especially during extreme dry years Stronger controls and conservation and restoration policies are urgently needed to preserve this key resource Snowpack reconstruction exercises may provide a long term context of natural variability for regional water management plans.