Climate changes of hydrometeorological and hydrological extremes in the Paute basin, Ecuadorean Andes

Investigation was made on the climate change signalfor hydrometeorological and hydrological variables alongthe Paute River basin, in the southern Ecuador Andes. An adjusted quantile perturbation approach was used for climatedownscaling, and the impact of climate change on runoffwas studied for two nested catchments within the basin. Theanalysis was done making use of long daily series of sevenrepresentative rainfall and temperature sites along the study area and considering climate change signals of global and regional climate models for IPCC SRES scenarios A1B, A2and B1. The determination of runoff was carried out usinga lumped conceptual rainfall–runoff model. The study foundthat the range of changes in temperature is homogeneous foralmost the entire region with an average annual increase ofapproximately +2.0 C. However, the warmest periods of theyear show lower changes than the colder periods. For rainfall, downscaled results project increases in the mean annual rainfall depth and the extreme daily rainfall intensities along the basin for all sites and all scenarios. Higher changes in extreme rainfall intensities are for the wetter region. These lead to changes in catchment runoff flows, with increasing high peak flows and decreasing low peak flows. The changes in high peak flows are related to the changes in rainfall extremes, whereas the decreases in the low peak flows are due to the increase in temperature and potential evapotranspiration together with the reduction in the number of wet days.

Jaar van publicatie:2014