Evaluación del desempeño de la teledetección para estimar niveles de Clorofila-a: estudio de caso en la laguna de Tota usando recursos de acceso libre

Abstract

The Sentinel mission, developed by the European Space Agency (ESA), consists of a series of satellites designed to collect vast amounts of data, which are then transformed into images and information used in the European Commission's Copernicus program. This document proposes a methodology to determine chlorophyll-a levels using satellite images obtained from Sentinel-2, processed with the SNAP software, also developed by the ESA. The selected study area is Laguna de Tota, located in the department of Boyacá, Colombia, a region of interest due to environmental issues associated with onion crops along its shores, where poor environmental management has been identified. The results were obtained through the application of various algorithms, including CR2CC within the SNAP software. However, when these results were compared with in-situ samples, a lack of correlation was observed, prompting further analysis that considered temporal factors, the specific characteristics of water bodies, among other variables. After processing with eight different algorithms, it was concluded that none of the models corresponded or closely matched the actual field-measured values, as these models are empirical and directly influenced by the physical characteristics of each water body. Finally, a model was developed using linear regression, combining field data with the digital levels of the 13 satellite bands. This model proved to be significantly reliable both globally and individually, with a confidence level of 89%.