Spectral mapping of the Paraíba do Sul River plume (Brazil) using multitemporal Landsat images

Abstract

Abstract. Coastal zones are influenced by oceanic, atmospheric, and continental forces, which make them highly vulnerable to climate and anthropogenic changes. The Paraíba do Sul River (PSR) Estuary (Brazil), is especially affected by intensive industrial, urban, and rural activities, along its catchment area. Few works, though, have been done concerning the impacts of these changes. Remote sensing is, thus, an important and unique tool to assess the past scenes for a temporal analysis. The present work aimed to analyze spatial-temporal trends of the PSR plume from 1985 to 2009, using Landsat 5 TM images. Two spectral classification methods were used to map the river plume: maximum likelihood and spectral linear mixture analysis (SLMA). The images corresponded to the months of greatest river discharge, totalizing 11 cloud-free images. Geographical, radiometric, and atmospheric corrections were applied to the five spectral bands used for the classification. Both methods showed good results, however the SLMA provided more information of the water constituent's distribution. The sediment river plume and inner shelf phytoplankton dominated waters showed a negative trend associated with a diminishing of the river discharge. Further works concern in situ validation of the classifications, biooptical modeling, and more investigations of climate and anthropogenic changes on the PSR.C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).

Carbon dioxide sources and sinks in the delta of the Paraíba do Sul River (Southeastern Brazil) modulated by carbonate thermodynamics, gas exchange and ecosystem metabolism during estuarine mixing

“…The river discharge in the estuary follows a seasonal cycle, with high water flow in summer and early spring and low water flow in winter and early autumn, with discharges averages of 1158 and 444 m 3 s -1 , respectively. The river discharge modulates the residence time of waters in the mixing zone (Souza et al, 2010) and the extension of the river plume in the adjacent coastal ocean (Rudorff et al, 2011). During low water flow, the plume is reduced and it takes approximately 10 days for the water to reach open ocean (salinity 35), whereas during high water flow, the plume is extended along the shelf and the residence time decreases to 6 days (Souza et al, 2010).…”

“…The water current velocities were taken from Ovalle et al (2013). Rudorff et al (2011) calculated the spatial coverage of the Paraiba do Sul River plume applying a spectral linear mixture analysis. The authors proposed a linear regression to estimate the surface area of the estuarine plume in the coast as a function of the historical river discharge.…”

Influence of estuarine dynamics on macrobenthos spatial variability along the southeast continental shelf of Brazil

“…According to Carvalho et al (2002), the PSR shows a large interannual variation of suspended particulate matter discharge (0.8 to 2.0×10 6 t/year), whereas other results indicate a discharge of 0.3×10 6 t/year of dissolved organic carbon (Figueiredo et al 2011, Ovalle et al 2013. The water chemistry information associated with spectral mapping of the PSR plume suggest that the continental input provides an important contribution towards the macrobenthic distribution, abundance and diversity in open estuarine areas and continental shelves (Rudorff et al 2011).…”

Remote Sensing Technologies for the Assessment of Marine and Coastal Ecosystems

“…Some work has also been done using satellite sensors with higher spatial resolutions such as LANDSAT TM and ETM plus images (e.g. Guneroglu et al 2013;Rudorff et al 2011;Hellweger et al 2004;Lira et al 1997) or SPOT data (e.g. Doxaran et al 2002;Ouillon et al 1997).…”

“…These spectral characteristics can be used to access the major factors affecting water quality in coastal water bodies (e.g. Total Suspended Matter (TSM) and dissolved organic matter (DOM)) (Vanhellemont and Ruddick 2014;Tang et al 2013;Zhu et al 2013Zhu et al , 2014Liew et al 2011;Vantrepotte et al 2011;Nechad et al 2010;Rodríguez-Guzmán and Gilbes-Santaella 2009;Wang 2009;Teodoro et al 2007a, b;Zhou et al 2006;Bustamante et al 2006;Ruddick et al 2003); to identify, characterize and analyze river plumes (Mendes et al 2014;Guneroglu et al 2013;Gonçalves et al 2012;Rudorff et al 2011;Teodoro et al 2009a;Otero et al 2008); to extract estuarine/coastal sandy bodies (Teodoro and Gonçalves 2012;Chowdhury et al 2011;Teodoro et al 2011a, b;Silveira and Heleno 2009;Baptista et al 2008); to identify beach features/patterns (Teodoro 2015;Teodoro et al 2009bTeodoro et al , 2010Teodoro et al , 2011bTeodoro et al , c, 2013Mujabar and Chandrasekar 2012;Harris et al 2011;Pais-Barbosa et al 2009); and to evaluate the changes and integrity (health) of the coastal lagoon habitats (Gutierres 2014;McCarthy and Halls 2014;Bustamante et al 2013;Vahtmäe and Kutser 2013;…”