Application of Free Software (GNOME) for Simulation of Oil Spills Trajectories in a Sector of Magdalena River (Colombia)

Abstract

According to the National Environmental Licenses Authority –ANLA, between 2004 and 2017, there were around 6.300 oil spills in Colombia, 40 % of which affected freshwater bodies. However, at the national level, the use of spill behavior prediction tools is not very extensive, due to the high costs of commercial software. Therefore, the main objective of this paper was to use the free software GNOME (General NOAA Operational Modeling Environment) in a sector of the Magdalena river (most important Colombian river). A collection of 54 instantaneous spills scenarios were simulated. Where a variation in the hydrocarbons type, volume spilled, wind direction and the time elapsed after effusion were considered. The comparison of the spill scenario’s mass balance showed that during the first six hours regardless the wind direction most of the hydrocarbons are deposited on banks, except for gasoline. After this time, the hydrocarbons are affected by environmental conditions and are volatilized, decreasing the remaining in water surface and banks. The results obtained were consistent with the literature respect to the volume of evaporated product is greater in the lighter products. The primary fate of spilled oil coincided with the previous modeling in the same sector of the river with software for private use. In both cases, the most probable destination of the hydrocarbons were the riverbanks. Since there are no other similar studies in Colombia, there was not possible to establish a comparison of results regarding the effect of wind direction and hydrocarbon type (specifically for the study sector). In conclusion, GNOME is an open-access software which evaluates the main processes that influence the oil spill’s displacement (diffusion, evaporation, and dispersion) offering consistent results. The novelty of this paper is that it is the first application of GNOME in a Colombian river, as an alternative for increasing the use of numerical modelling tools in the design of contingency plans in the country.