Análisis de cambio del rendimiento hídrico actual y bajo escenarios climáticos futuros en la región sur del Ecuador

Abstract

In this study, the average annual water yield for the 1970-2015 period was estimated and with climate change projections for the 2030s, 2050s, 2070s and 2080s in nine hydrographic basins of the southern region of Ecuador using the InVEST water yield model based on the Budyko framework using the InVEST water yield model based on the Budyko framework using the InVEST water yield model based on the Budyko framework. The model estimates annual surface run-off at the pixel, sub-basin, and basin level considering the following variables: precipitation, actual evapotranspiration, land cover/use, soil depth, and available water content for plants. The study involved the generation of the current variables of precipitation and reference evapotranspiration. And the use of the projected variables of two General Circulation Models (GCM) of the Coupled Model Intercomparison Project Phase 5 Fifth (CMIP5): MIROC-ESM-CHEM and MRI-CGCM3, under two scenarios, RCP4.5 and RCP8.5. The results showed that the Mayo and Zamora basins had the highest water production, corresponding with 934 and 1218 mm per year, respectively, while the Alamor and Catamayo basins had the lowest water production, corresponding with 206 and 291 mm per year, respectively. According to the MIROC model, average changes of -33 and 67 mm are expected in the scenarios RCP4.5 and RCP8.5, respectively; while, the MRI model presents increments of 130 and 223 mm for the scenarios RCP4.5 and RCP8.5, respectively. GCM generally foresee that the water yield will increase in the middle and lower zones of the watersheds, while in the upper areas of the basins that originate in the Andes mountain range there will be a reduction in water production.