Estimates ofturbulent parameters in the mid-latitude Valdivia River Estuary

Abstract

The Valdivia River Estuary (VRE) is in the Los Ríos Region, Chile. It is an area of great ecological wealth, which has also contributed to the economic and cultural development of the city of Valdivia and the cities in the interior of the province. Research dedicated to the study of its hydrodynamics in recent years has increased but obtaining parameters that describe its behaviour with updated data is a key step for the adjustment of numerical models. Using data of subtidal currents (ADCP) provided by campaigns conducted in 2017 by the regional Dirección de Obras Portuarias, filtered through a harmonic analysis and ordered with an idealized model, allowed determining estimates of the eddy viscosity coefficient (Av) in different sections of the VRE. The Av obtained from the deepest currents, delivered by the ACDPs, show a clear linear decreasing trend towards the head of the estuary. The station closest to the mouth of the estuary was estimated at Av=4.7·10-4 m2s-1, while the station closest to the head of the estuary was estimated at Av=2.4·10-4 m2s-1. Additionally, using the current plots resulting from the deepest ADCPs, it is determined that the estuary describes a partially mixed estuarine behavior during the time of the campaigns.