Wetland Mapping With Multitemporal Sentinel Radar Remote Sensing in the Southeast Region of Brazil

Abstract

Abstract. A classification method with multi-temporal images of synthetic aperture radar (SAR) combined with Geographic information system, geoinformation data, and field validation, was applied for wetland mapping accuracy and typology. Wetland mapping is vital for management and conservation, particularly under environmental pressures such as wetland drainage and land reclamation. The aim of this study is to develop an accurate mapping of wetlands and open water systems of the Lower Doce River Valley - LDRV (Southeastern Brazil) with Synthetic Aperture Radar (SAR) imagery, using multitemporal classification techniques and ground truth validation. Sentinel-1B SAR imagery from 2016 and 2019 was processed with Google Earth Engine (GEE). Monthly median imagery condition for the rainy season was obtained and K-means unsupervised classification was applied. The study yields 4,157 wetlands, 262.27 km2 with predominant small patches. Fieldwork revealed three main wetlands categories: coastal wetlands, inland wetlands and artificial wetlands. The results have shown an overall accuracy of 81.9% and a Kappa coefficient of 0.71. Wetlands, non-wetlands, and open waters classes present accuracy of 50, 80 and 95%, respectively.

Periphytic algal flora of the lower Doce river basin after ore tailings flow, Espírito Santo State, Brazil: Sampling design and methods

“…Study area -Lower Doce River basin is fully located in the State of Espírito Santo, southeast Brazil (41º30' to 39º30'W and 19º30' to 20º30'S) in the Tertiary plateaus formed by Barreiras Formation and the Quaternary Coastal Plain (Salinas et al 2020). Its drainage area covers about 11,921 km² and contains about 90 smaller lakes, including the second largest Brazilian freshwater lake (Juparanã) (Barroso et al 2012).…”

“…Its drainage area covers about 11,921 km² and contains about 90 smaller lakes, including the second largest Brazilian freshwater lake (Juparanã) (Barroso et al 2012). According to the Köppen classification, region climate is Aw (humid tropical with dry winter) (Nóbrega et al 2008) and seasonality can be divided into dry (April to September) and rainy (October to March) seasons (RRDM 2019), with 1,123 mm of average annual rainfall (Salinas et al 2020). Lakes and lagoons in Lower Doce River, due to their formation, are often connected with Doce River in a bidirectional flow that varies according to the level of the river.…”