Monitoramento multitemporal de sedimentos em suspensão em trecho do Rio Parnaíba, utilizando índice NDWI

Abstract

The study seeks to evaluate the spectral response of the NDWI index of the Parnaíba River perimeter located between the Governador José Sarney and Engenheiro Antonio Noronha bridges, located in the urban area, between the municipalities of Teresina-PI and Timon-MA, having an area of 1.47 km², between the years 2015 and 2019, with the purpose of monitoring the deposition of solid waste during the training period. The scenes used for the study were from the LANDSAT 8 satellite, OLI sensor, orbit/point 219/64. In it, four classes were predicted: Dense Vegetation, Undergrowth, Sand and Water, showing differences in all classes highlighted, mainly in water, where there was a reduction of 0.11 km² and sand, and an increase in Dense Vegetation. , of 0.093 km². To corroborate the results obtained, the Kappa index was used, linked to the application of Supervised Classification, obtaining values between 0.68 (68%) and 0.77 (77%), which are considered very good. The study proved to be efficient in discriminating different physiognomies, with low cost and speed. The discrepancies between the image acquisition data do not present changes in the quotients, as the rainfall does not represent a change in the results.