Hydrological significance of rock glaciers and other periglacial landforms as sustenance of wet meadows in the Patagonian Andes

Abstract

Wet meadows in mountainous areas are important environments for the ecosystem services provided, mainly those associated with the water supply to local people. In the region of the Patagonian Andes wet meadows are spatially associated with rock glaciers and other related periglacial landforms. The aim of this work was to determine the hydrological significance of these geoforms as sustenance of wet meadows in La Hoya watershed, located in Northern Patagonian Andes. We carried out a geomorphological mapping of the depositional units, wetlands, springs and streams located in the area. During fieldwork, we checked and completed this information, together with sedimentological analysis of the morphosedimentary units and hydrodynamic and salinity measurements on streams and springs. Finally, we performed hydrogeological schemes to outline the geological and geomorphological controls regulating water flows and the development of wet meadows. Results obtained show a constant flow from rock glaciers and solifluction lobes towards wet meadows during the driest period. The principal contribution of water comes from snowmelt and rain, constituting a short and intermediate-term water input. Rock glaciers and solifluction lobes constitute effective water storage depositional units, and the groundwater discharged from these landforms is constant, even during the dry season, which keeps wet meadows moist and evergreen year-round.