Spatial and temporal variations of the inherent optical properties in a tropical cascading reservoir system

Abstract

In order to verify the effect of a cascade system in the water quality of two tropical reservoirs in Brazil, this work proposed to make use of the inherent optical properties (IOPs) as well as the specific inherent optical properties (SIOPs). From upstream to downstream, Barra Bonita (BB) is the first in a set of six reservoirs along Tiete River and Nova Avanhandava (Nav) is the fifth reservoir. BB is eutrophic whilst Nav is an oligotrophic environment. According to the IOP and SIOP analysis, it was possible to attest that BB was organic matter dominated and Nav was inorganic matter. These differences are noticeable in bio-optical modeling, must be considered different approaches to retrieve water quality parameters in both sites, once, the models take into account the specific information about the IOP and their relation with the optically active components (OACs) concentration. In addition, the results of this paper can provide comparable data to other water systems and improve the comprehension about the optical properties of complex water bodies.