Hydro-dynamic modeling for identification of flooding zones in the city of Tunja

Abstract

The present article elaborates a hydrological and hydraulic model of the Jordan and the Vega rivers in the environs of the city of Tunja in order to enable the identification of potential flood zones. The first model was implemented in HEC-HMS together with the Geographic Information System (ArcGIS) and the incorporation of the HEC-GeoHMS extension; based on official information provided by Corporacion Autonoma Regional de Boyaca (CORPOBOYACA) and El Instituto de Hidrologia y Metereologia de Colombia (IDEAM). The considerations adopted in this project were defined taking into account the existing information and the specific characteristics of the basin of the Jordan and the Vega rivers. Flow hydrograms used to feed the boundary conditions of the hydraulic model were derived from the hydrological model. The hydraulic calculations were carried out in IBER two-dimensional model for a critical return period covering 100 years. The results given correspond to maps of high hazard in the city of Tunja, which were generated from data of depth and velocity; this information allowed the identification of areas of interest (areas susceptible to overflow of the Jordan and the Vega rivers), and generated cross-sectional profiles; next, impacts and effects in the surrounding areas were identified, permitting proposals of options to correct, prevent and mitigate impacts of flooding.