Análisis comparativo de la influencia del caudal base de las subcuencas de los ríos Machángara, Tarqui y Yanuncay en el caudal base del río Paute durante el periodo de estiaje de los años 2009 a 2011

Abstract

Drying is a natural phenomenon that is manifest through rainfall below normal limits with duration, frequency and severity difficult to predict (Pacheco, Parra, & Avilés, 2017). During the dry season, the flow of the rivers comes mainly from the flow of groundwater (base flow). In the period 2009 to 2011 Ecuador went through different critical dry seasons, affecting the country's electricity generation. The Paute Hydroelectric Complex was also affected due to the low level of its reservoir, whose main tributary is the Paute river; and with it the water supply of the sub-basins that converge in it. Therefore, the objectives of this study are to know how in that period the base flow of the Paute river was influenced by the sub-basin of the Machángara river with artificial regulation in relation to the sub-basins of the Tarqui and Yanuncay rivers in which there is only natural regulation, and to carry out a comparative analysis of the characteristics associated with the base flow rate between them, through the use of non-linear recession analysis and digital filters.

The sub-basin of the Machángara river during the analysis period contributed with 15% of base flow to the middle basin of the Paute river, in relation to the sub-basins of the Tarqui and Yanuncay rivers with 6% and 12% respectively. Also, its storage capacity was higher compared to the other sub-basins, a condition that may be due to existing reservoirs in the area. This study constitutes a hydrological analysis tool for the adequate arrangement and management of the water resource through the understanding of the physical characteristics associated with the base flow in sub-basins with natural and artificial regulation in the Andean region of Ecuador, especially in the Paute river basin.