Análisis de tendencias temporales del índice mejorado de la vegetación (EVI) en tres ecosistemas de la subcuenca del río Chambo durante el período 2013-2020.

Abstract

The aim of this research was to analyze the EVI vegetation index over a period of time (2013 to 2020) using satellite images, which allowed monitoring the state of vegetation, increasing its sensitivity in cases of high biomass densities. The methodology used for the first objective was based on downloading Landsat 8 satellite images using the Google Earth Engine platform, to delimit the study area in which the EVI index was determined, ArcGIS 10.2 software was used with the formula: 2.5*(img1["B5"]- img1["B4"])/(img1["B5"]+6*img1["B4"]- (7.5*img1["B2"])+1). For the second objective, the TREND software was used it allowed detecting the most reliable trend analysis between ecosystem precipitation. And for the third objective, a tree of problems, objectives and alternatives was elaborated using the logical framework matrix, which consisted on developing a series of steps in where the necessary information for the research would be collected and analyzed. The results showed a maximum annual average EVI value for the evergreen shrubland and páramo grassland ecosystem of 0.28 in 2015 and a minimum of 0.26 in 2020. For the páramo grassland ecosystem, the maximum EVI value was 0.28 in 2015 - 2017 and its minimum value was 0.25 in 2013 - 2018. Finally, the ecosystem Herbazal y Arbustal evergreen subnival of the páramo, presented a maximum value of 0.24 for the year 2014 and minimum value of 0.22 for the year 2013. It is concluded that this research would be a part of the elaboration of the logical framework matrix of the proposal for the management and conservation of ecosystems. It is recommended to follow up this research in uninterrupted periods to observe the ecosystems variation.