Dinâmica do risco de incêndios sob efeito do El Niño em paisagem do bioma Caatinga em Petrolina - PE

Abstract

Remote sensing techniques have been used since the 1960s to work on a particular object or specific area. Over time, technologies have gained improvements and new software and high resolution satellites have emerged. The Landsat-8 satellite can capture scenes up to 705 km away from earth, with a percentage of 10% of clouds, these scenes can be processed and studied for a certain purpose, among these was the dynamics of fire risk under the effect of El Niño in landscape of the Caatinga Biome. Therefore, it is intended to study the vulnerability of Caatinga and the use of monitoring technologies. The objective of this work is to evaluate the influence of El Niño on the dynamics of fire risk under the landscape of the Caatinga biome in Petrolina-PE, monitoring the risk of fire in relation to the severity of El Niño. Images of the Lansat-8 satellite in the municipality of Petrolina-PE were obtained from the USGS website. The following criteria were adopted for image selection: Data from 2015 to 2020, counting from August 1st to December 31st, at times when there are few precipitations, few clouds and high temperatures due to the warmer months. The tool in data processing was Qgis software, a free license software, indicated for those seeking high quality in academic work in the area of Remote Sensing. In the interval of these years, six fire risk maps were obtained. Togenerate the forest fire risk maps and adopted the AHP methodology, widely used by several authors. Where we obtained eight variables: hypsometric map, land use and occupation, slope orientation, slope, road system, precipitation, surface temperature and vegetation index of the normalized difference. According to the results, a temporal analysis of fire risks was obtained, proving that the years 2015 to 2018 had a continuous increase, and in 2019 and 2020 there was a fall in fire risk. Between these last years there was an El Niño and a La Niña and 2020 was the year that the pandemic occurred, that is, there were few transport flows on the highways, causing low risk of fires.