Maximal, minimal and mean surface runoff in colombia: How is it distributed?

Abstract

For 418 hydrological stations, the time series of maximal, minimal and mean annual runoff were built and analyzed to establish a more suitable theoretical probability density function (PDF) or cumulative density function (CDF) to describe the annual runoff in Colombia. For each time series the empirical CDF was compared to normal, lognormal, Gamma and Weibull theoretical CDFs. The Kolmogorov, Smirnov and Pearson criteria were used to test the goodness of fit at a significance level α=0.10. Our results show that the Gamma CDF is the best model to describe maximal, minimal and mean surface runoff. This work is preliminary research that establishes the baseline for building hydrological and climate change scenarios in a probabilistic manner. Further research will concentrate on how probabilistic runoff patterns will evolve under climate change conditions.