Evaluación multitemporal del cambio de cobertura y uso del suelo en la cuenca baja del Río Chambo.

Abstract

The present study, conducted in the lower basin of the Chambo River, had as main objective to evaluate the change of coverage and land use in multi-temporal spaces and the fate of the effects of the change in land use in the physicochemical properties of the area of study. Landsat 5 images from 1998 and Landsat 7 from 2016 were used to analyse the change in coverage; processed by specialized software and subjected to a validated supervised classification with a percentage of global precision and the Kappa coefficient. The evaluation of the change was made through the Land Change Modeler module, whose changes were represented in losses, gains and persistences of the plant covers that were later illustrated in thematic maps. The results indicate that the changes of coverage favour the “Páramo” with a gain of 26.76% while the forest lost 25.49%, so also the agricultural frontier had a gain of 10.48% and the ground without coverage 3%. Additionally, 50 soil samples from four different uses (forest, “Páramo”, crops and without coverage) have been subjected to physio-chemical analysis, without significant difference between the parameters, but these tend to form components that correlate them. The influence of natural aspects, such as the eruption of the Tungurahua volcano, and the anthropogenic activities derived from it; it allowed us to appreciate the vulnerability of the forests and the advance of the agricultural frontier; as well as an ecosystem competition and trends of change due to agricultural interference that accelerate the processes of changes in coverage and land use. An elementary analysis of agricultural soils is recommended because heavy metals from volcanic activity affect the quality of the soil and present a threat to food security.