USE OF LANDSAT-8 SATELLITE IMAGES FOR THE ESTIMATION OF WATER QUALITY PARAMETERS IN THE ABREUS RESERVOIR, CIENFUEGOS, CUBA

Abstract

The monitoring and conservation of the quality of surface water in bodies of water such as lakes or reservoirs is one of the main concerns worldwide. The present study aims to evaluate the possibilities of using Landsat-8 satellite images for the estimation of water quality parameters such as pH and temperature and transparency of the water in the Abreus reservoir, through mathematical algorithms. In the research, field samples collected between 2016 and 2021 by the Center for Environmental Studies of Cienfuegos (CESC) and images from the Landsat 8 satellite were used. With these data, the STATGRAPHICS program and the use of regression techniques are selected and three mathematical models were validated, one for each parameter. In the case of water transparency, a polynomial model was calibrated that uses the ratio B5/B4 (R2=86.50 %), in terms of pH, a model of multiple linear regression that groups some quotients created with the bands 1-7 (R2=80.68 %) and for temperature, a polynomial was calibrated that uses the surface temperatures obtained through a simple channel equation (R2=55.25 %). These models were applied to one of the satellite images, which allowed obtaining thematic maps that reflect the spatial distribution of these parameters in the body of water, for that date.