Spectral Response and Limnological Characteristics of the Nhecolândia Pantanal Lakes

Abstract

Among the Pantanal sub-regions, Nhecolândia is unique in that it is characterized by a peculiar landscape with more than 20,000 lakes, including ones with brackish water (saline lakes) and others of fresh water (freshwater lakes). For a better understanding of this environment it is important to carry out physico-chemical studies of the lagoons; however, data surveys in the field become expensive and almost impossible due to the vast area and the fact that samples require treatment in appropriate laboratories. Accordingly, in order to facilitate the characterization of large, inaccessible areas such as these, we applied geotechnologies to aid research into the physical, chemical, and biological factors in the study area. Thus, in this work, in addition to water samples collected from 32 locations, satellite images and vegetation indices were also used to identify the freshwater and saline lakes of Nhecolândia. The analyzed variables were chlorophyll a and total suspended solids, which can also be measured through satellite images. As a result, based on the variables analyzed in the field and the established criteria, 21 freshwater lakes and 11 saltwater lakes were identified. By comparing results, we found that our results are as accurate as laboratory analyses, therefore, satellite images can be effectively used for low cost and flexible evaluation of aqueous bodies distributed over large areas.