Mapas de peligro por inundación del río Chibunga en el tramo de influencia al parque lineal ubicado en la ciudad de Riobamba

Abstract

The Chibunga River crosses the city of Riobamba in a southeast direction. In recent years, the growth and expansion of the urban area of the city has caused educational institutions, public and private buildings, infrastructure works and recreational areas to settle on the banks of the Chibunga River; in the area surrounding the Ecological Park. These settlements have been carried out without considering the risk to which they would be exposed when presenting extraordinary rainfall scenarios in the basin. The main objective of this work was to estimate the maximum flow rates of the Chibunga River in the section of hydrological interest and for different return periods between 5 and 100 years. Given the absence of hydrometric information in the study basin, a situation that limits the estimation of maximum flows through the statistical - probabilistic method, a precipitation - runoff numerical model of the semi-distributed Chibunga river basin was developed. This hydrological model was developed in the RS-Minerve software, the basin integration scheme consisted of 8 sub-basins, 3 transit zones and 4 joints. The physical characteristics of the basins were estimated with the help of digital elevation models and GIS tools. The design storm was selected based on the Study of Intense Rains (INAMHI, 2015), assuming a temporary distribution of rain based on Huff's Curves. Effective precipitation was estimated using the SCS Curve Number method for a moisture condition II. Finally, the triangular unit hydrogram was used for the transformation from effective precipitation to Flow. Finally, hydrograms were obtained for the established return periods and whose peak flows were validated in a preliminary way according to an envelope of specific flows depending on the area.