Análisis del balance hídrico del lago Llanquihue, región de Los Lagos.
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Date
2022
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
Este trabajo aborda el estudio hidrológico de la cuenca del Lago Llanquihue, donde se realiza un balance hídrico sobre el lago, con un periodo de estudio de 2010 hasta 2018 para estimar variables de precipitación, evapotranspiración, caudal aportante al lago, etc. para finalmente estimar infiltraciones y exfiltraciones del lago, utilizando mediciones fluviométricas y meteorológicas de estaciones de la DGA y otras instituciones, uso de modelos como CR2METv2, y transposición de caudales.
Entre las características hidrológicas del lago se destacan la reducida superficie de su cuenca aportante con relación a la superficie del espejo de agua (1625 km2 / 860 km2), la pequeña magnitud de sus afluentes y el reducido caudal medio de su único efluente Río Maullín (aproximado en 90 m3 s-1). Estos atributos hacen que el principal aporte de agua sea por precipitaciones directas sobre su superficie, y que la renovación teórica de sus aguas demore décadas.
Se estimó que existe un flujo anual promedio durante el periodo 2010-2018 de: precipitación: 6310 Hm3 Evapotranspiración: 2397 Hm3 (38%) Caudal aportante: 1465 Hm3 (23%), y un caudal saliente: 2346 Hm3 (27%) El aporte de agua subterránea es muy variado año a año, aumentando de intensidad cuando el nivel del lago disminuye, esto ocurre en años más secos, como se demuestra entre los años 2014 y 2017, en los que se observa una tendencia hacia la disminución del nivel del lago, sin embargo, se podría estimar un promedio de 362 Hm3 para invierno y -613 Hm3 en verano.
This study investigates the hydrology of the Llanquihue Lake Basin, where a water balance was carried out during the period from 2010 to 2018. Estimation of mean annual precipitation, evapotranspiration, and streamflow contributing to the lake were used to quantify lake infiltrations and exfiltrations. Fluviometric and meteorological measurements from the National Water Bureau (DGA) stations and other institutions were used, as well as the CR2METv2 meteorological product, and a flow transposition technique. Among the hydrological characteristics of the lake, the reduced surface of its contributing basin in relation to the surface of the water mirror, the small magnitude of its tributaries and the reduced average flow of its only effluent Maullín River, approximately 90 m3 s-1, stand out. These attributes mean that the main contribution of water to it is due to direct precipitation on its surface, and that the theoretical renewal of its waters takes decades. It was estimated that there is an average annual flow of: precipitation: 6310 Hm3 Evapotranspiration: 2397 Hm3 Contributing flow: 1465 Hm3, outgoing flow: 2346 Hm3. The contribution of groundwater is very varied from year to year, increasing in intensity when the level of the lake decreases, this occurs in drier years, as demonstrated between the years 2014 and 2017, in which a trend towards a decrease in the lake level, however, an average of 362 Hm3 for winter and -613 Hm3 in summer could be estimated.
This study investigates the hydrology of the Llanquihue Lake Basin, where a water balance was carried out during the period from 2010 to 2018. Estimation of mean annual precipitation, evapotranspiration, and streamflow contributing to the lake were used to quantify lake infiltrations and exfiltrations. Fluviometric and meteorological measurements from the National Water Bureau (DGA) stations and other institutions were used, as well as the CR2METv2 meteorological product, and a flow transposition technique. Among the hydrological characteristics of the lake, the reduced surface of its contributing basin in relation to the surface of the water mirror, the small magnitude of its tributaries and the reduced average flow of its only effluent Maullín River, approximately 90 m3 s-1, stand out. These attributes mean that the main contribution of water to it is due to direct precipitation on its surface, and that the theoretical renewal of its waters takes decades. It was estimated that there is an average annual flow of: precipitation: 6310 Hm3 Evapotranspiration: 2397 Hm3 Contributing flow: 1465 Hm3, outgoing flow: 2346 Hm3. The contribution of groundwater is very varied from year to year, increasing in intensity when the level of the lake decreases, this occurs in drier years, as demonstrated between the years 2014 and 2017, in which a trend towards a decrease in the lake level, however, an average of 362 Hm3 for winter and -613 Hm3 in summer could be estimated.
Description
Habilitación profesional presentada a la Facultad de Ingeniería Agrícola de la Universidad de Concepción, para optar al título de Ingeniero Ambiental
Keywords
Aguas subterráneas, Evapotranspiración, Hidrología -- Métodos estadísticos