Evaluación del comportamiento hidrológico de la cuenca del río Tomebamba a través del análisis de hidrogramas

Abstract

High mountain ecosystems play a very important role due to their capacity of regulation and water supply to some cities of Ecuador. Therefore, it is essential to study hydrological processes that occur in these ecosystems. However, in Ecuador there are currently no studies that address the internal behavior of an Andean basin during flooding events, based on a distributed monitoring of water flows, at various points within the same basin. In this investigation, an analysis of the hydrological behavior of the Tomebamba River basin along the altitudinal gradient was performed, using hydrological indexes that describe the basin’s behavior and reaction in flooding events. The hydrological regulation analysis was carried out through flow duration curves, base flow indexes, and persistence of high and low flows. Additionally, events that cause flooding were determined, applying reactivity indicators, in order to compare the hydrological response that each microbasin has against high water flow events. Results demonstrated greater hydrological regulation in the upper region of the basin considered in this study, justifying the importance of paramo ecosystem conservation. On the contrary, in the lower zone greater reactivity against precipitation events was evidenced, due to the negative effect of different anthropic activities. Finally, it was determined that the propagation time of a flooding event along the gradient is two to three hours. However, in some cases there are strong swellings that are not present in the upper region of the basin, but are observed in the middle to lower zone, which is corroborated with rainfall spatial variability studies.