Monitoramento da colheita florestal em plantios de Pinus elliottii através de imagens de satélite PlanetScope e SAR

Abstract

The monitoring of commercial forests by satellites assumes importance in the management of an enterprise and the associated risks, providing companies with fast and updated information necessary in forest planning and policymaker decisions. Therefore, the objective of the work was to evaluate comparatively the use of optical images of high temporal and spatial resolution of PlanetScope sensors and Synthetic Aperture Radar (SAR) Sentinel-1 data, and generate alternatives for monitoring forest harvest in Pinus elliottii plantations on the southern coast of Rio Grande do Sul. We used as a basis the data of effective planting, area of plots, 47 PlanetScope images, and 32 SAR images, for the year 2021. The intervention periods were identified due to the difference between the patterns of the time series of the planted forest area and the harvested area. The results showed that the images when used together allow us to identify and monitor the harvesting events in the plots studied. Levels and periods of harvest stop were identified, in line with field data. However, the presence of clouds in some PlanetScope images analyzed resulted in gaps in the identification of cuts at certain dates, suggesting the use of SAR images. With the analysis of the SAR images, it was identified a difficulty in the visual recognition of the harvesting patterns in the studied area. Thus, when used together and/or complementing the mapping of the harvest was more effective.