Diagnóstico ambiental por índices de vegetação no Parque Estadual Mata da Pimenteira no período chuvoso e seco

Abstract

Due to the monitoring needs, as well as the understanding of the vegetation conditions of the Mata da Pimenteira State Park, it was aimed to analyze vegetation indices generated with red and infrared bands, with Sentinel-2 images to verify the land cover in the rainy and dry period from 2016 to 2021. The study site is located in the municipality of Serra Talhada, Pernambuco. The images were processed in Google Earth Engine to obtain a composition of the two periods studied, then, in QGIS software version 3.18.3 (Zurich), the vegetation indices (NDVI and VCI) were determined by raster calculator, a calculation tool available in Qgis that uses as a basis the values of the pixels of the layers. After obtaining the indices, the descriptive statistics of the images were obtained and classified using the r.recode tool, with subsequent counting of the vegetation classes by r.report, so that from this, the thematic map for the analysis and diagnosis of the study area was made. The results indicate higher average NDVI for 2016 and 2017 with 0.7 in the rainy period, and 0.36 in the dry one. The VCI had its highest average in 2016 with 86.04 and lowest in 2018 with 63.63. In the rainy period more than 90% of the area was composed of the high vegetation density with the NDVI and VCI of the very light class. In the dry period, most of the area was of the class "low vegetation density" by NDVI and "severe" by VCI.