REMOTE DETECTION OF POTENTIAL EFFECTS OF INTENSE DROUGHTS ON THE SEASONALITY OF WATER IN THE FLUVIAL-LACUSTRINE COMPLEX OF CURUAÍ, AMAZON RIVER, PARÁ, BRAZIL

Abstract

Introduction: studies reveal that Amazon region is vulnerable to climatic extremes such as droughts, in this context, remote sensing, together with other spatial analysis tools, has been widely used for monitoring environmental activities, including this natural phenomenon, and continuously improving measurements, spatial and temporally. Objective: to monitor the effects of an extreme drought on the hydric seasonality of the Curuaí lake system, Amazon River, Pará state, Brazil; through the use of geotechnologies such as remote sensing and GIS. Methods: the present work made use of a Landsat-5 time series, flow and drought period in 2010; with application of NDWI - Normalized Water Difference Index, and subsequent vectorization of the contour of this water body, to determine the percentage of reduction in the water depth area in the most significant months, and compilation of associated information. Results: The NDWI on the time series showed satisfactory results in enhancing the aquatic surface, allowing the zoning of these areas and comparing their reductive percentage, which showed potentially harmful effects, with a reduction from 1,524 km2 to 338, 851 km2. Conclusion: The applied index obtained satisfactory results, showing how these geotechnologies, and their information extraction techniques, can be effective in monitoring potentially harmful natural phenomena over the study region; therefore, through more advanced studies, they can be effective for planning strategies to mitigate these impacts on the diverse ecosystems of the Amazon.