Estimation of the water balance of the colombian pacific region

Abstract

Using the surface water balance equation, the average annual runoff in the continental zone of the geographic domain of Central America for Coordinated Regional Climate Downscaling Experiment (CORDEX) is estimated, and results are validated along the Colombian Pacific rivers, namely Atrato, San Juan, Baudó, Patía and Mira, using historical streamflow records, as well as streamflows reported in the National Water Study. Precipitation was estimated using the Tropical Rainfall Measuring Mission (TRMM) and Climate Hazard group InfraRed Precipitation with Station (CHIRPS) data sets. Actual evapotranspiration was estimated using the Max Planck Institute (MPI) data sets, as well as the Choudhury and Budyko methods based estimates of potential evapotranspiration from Climatic Research Unit (CRU). Results allow concluding that the surface balance equation exhibits an almost perfect closure over the Atrato and Baudó Rivers, with errors on the order of 10-20%, whereas for the Mira River errors are on the order of 40%.