ANALISIS DE RESULTADOS....................................................................... 61

ABSTRACT

The Betania reservoir in the department of Huila, Colombia, has not only been the primary source of electricity generation in the southwestern of Colombia but also it has framed a prosperous economic activity around fish production in the form of intensive fish farming. However, the anthropic intervention processes in its development has generated environmental pressures on the waterbody, leading to deterioration of water quality and ecosystem balance. These production processes involve the intervention of chemical and biological factors that alter the natural processes and derive into the eutrophication of the waterbody due to the excess of dissolved phosphorus.

In this work, it was possible to establish the spectral signature of phosphorus and its visualization and distribution in the Betania reservoir through satellite images and the application of statistical methods for their digital processing, thus identifying its direct impact on the trophic states in the waterbody. Specifically, a multitemporal analysis for the years 2007 and 2020 was performed based on Landsat 5 and 8 images, respectively, applying band combinations established according to the defined spectral signature and its relationship with areas detected with biomass presence. Although, the 2007 image resolution did not provide the expected results, the 2020 image allowed to establish areas with phosphorus presence, mostly consistent with location areas of cages or pools of fish production.

KEY WORDS: Fish Farming, eutrophication, Digital Image Processing, Time-space analysis, Spectral Signature, Landsat