Determination of variability of flow duration curve for non-stationary effects in Colombia

Abstract

In this work, long term temporal changes are analyzed in several flow duration curves FDC from Colombian daily gauging stations by the mean of the application of non-parametric Mann-Kendall test, the Sen´s Slope Estimator and the slope of the linear regression of the time series. Characteristic flows were estimated aiming to analyze the existence of long-term trends in different flow magnitudes (percentiles corresponding to 95, 75, 25 and 1 percentage of exceedance). Additionally, standard deviation long term trend is estimated using a 10 years mobile window. Significant increasing trends are observed in the regions of Chocó (east) and Bajo Cauca (north-east) while decreasing trends did not present any particular spatial pattern. Long term trends magnitudes between –0.0068 m3/s/day and 0.047 m3/s/day were found.

Keywords

• caracterización de caudales
• tendencias a largo plazo
• prueba de mann kendall
• pendiente de sen
• enso