Assessment of the hydrological response to precipitation and temperature changes in the Peruvian Altiplano

Abstract

Mountain basins are considered the hydrologic systems most affected by climate change, estimating significant impacts on water resources and water demands. This study evaluates the hydrological response of a Peruvian Altiplano basin to changes in precipitation and temperature patterns. Knowing in advance the effect of climate change on water supply takes on relevant importance for decision-making in short, medium and long-term planning of water use and management of water resources. From the implementation of the Integrated Model of Climate Change and Water Resources (HydroBID), 30 climate scenarios were evaluated that considered changes in precipitation between -20 and +20 %, temperature between 0 and 6 °C, and combinations of these were formulated according to the projections for the study area available in the literature. The results showed that for every 10 % increase in precipitation there was an average increase of 23.4 % in flow; while for every 10 % decrease in precipitation, an average reduction in flow of 16 % was generated. Likewise, it was evidenced that for every 1 °C increase in temperature, an average 5 % reduction in flow was generated. It was determined that the variation of the precipitation rates, temperature and their interaction between them generate changes in the flows, showing effects on the temporal and spatial variation of the basin.