Implementation of the hydraulic modelling of urban drainage in the northeast sector, Tunja, Boyacá

Abstract

Historically, in the city of Tunja there has been a phenomenon of occupation of the natural channels of rainwater, altering the hydrology of the natural basins. Currently, the city is experiencing considerable and accelerated urban development towards the Northeast, which has resulted in overflows in the drainage system and floods that have affected residents. The current drainage system is not capable of registering the flow of water that leaves the urban sector due to a lack of instrumentation. In this study, precipitation and water flow equipment was installed in the northeastern district of the city, also known as Barrio Santa Ines. The basin was separated into 56 different sub-basins with physical and drainage parameters calculated for each sub-basin. The associated parameters were calibrated to the initial hydrological losses and roughness. A validated and calibrated urban drainage model was created in the program SWMM 5.1, allowing for the temporal hydrodynamic modelling of the system to be obtained. The model reproduces the real evolution of the system and was used in order to make predictions according to a maximum precipitation design event. This model resulted in the detection of two areas that are vulnerable to flooding. The identification of different sub-basins and the desegregation of the hydrodynamic model resulted in a reduction in the uncertainty of the evolution of water flow in the system.