Monitoring coastal evolution and associated littoral hazards of French Guiana shoreline with radar images

Abstract

This paper aims at illustrating different case examples of monitoring active coastal evolutions using remote sensing synthetic aperture radar images (ERS 1-2 and Envisat) in humid tropical areas. Effectively, the radar satellite images may be acquired under most climate conditions, especially in cloudy tropical areas. As case examples, we studied herein French Guiana shoreline and its fast evolution under the combined influences of sea currents, sediments and swells. We focused on two aspects of French Guiana littoral evolution: (1) sedimentation and erosion processes linked to mud banks displacements around Kourou City, and (2) around Iracoubo village. Lastly, we compared this short-term sedimentation balance with long-term data showing the discrepancies of short-and long-term littoral evolutions on whole French Guiana. To conclude, this work demonstrates the importance of SAR imagery to provide high-quality and high-frequency update geographic information for coastal management and littoral hazards especially in such tropical humid and cloudy areas.

Morphological effects of damming on lower Zambezi River

“…Besides sediment yield, however, other complex physical mechanisms are involved in the evolution of the delta morphology and extension, such as sea level fluctuations, subsidence, human intervention, and, above all, sediment redistribution by the sea. Different methods have been developed to quantify delta evolution: aerial photo, radar images, ground penetrating radar, sonar bathymetry, sediment sampling, grain size distribution analysis, as well as various mathematical models to simulate sediment transport by waves and currents (Liu et al, 2000;Sun et al, 2002;Pelpola and Hickin, 2004;Trebossen et al, 2005). At an extremely large geological time scale Walford et al (2005) evaluated the Zambezi delta evolution and the river solid sediment load history of the last 120 Ma using a seismic reflection profile system, making some assumptions on the compaction history in order to construct isochore maps of solid sediment load and yield as a function of geological time.…”

A review and meta-analysis of remote sensing data, GIS methods, materials and indices used for monitoring the coastline evolution over the last twenty years

“…Furthermore, c) support vector machines (SVMs) used to improve the mapping process (George et al, 2015;Joevivek & Saravanan Sakthivel, 2013;Yawo et al, 2018), d) edge detection used as a shoreline proxy (Vasilis et al, 2018;Paravolidakis et al, 2016;Murray, 2013;Fugara et al, 2011), e) Supervised Classification used by Shalaby and Tateishi , f) Unsupervised Classification used by Thampanya et al (2006), g) Natural Breaks (Jenks) used by Andredaki et al (2014), h) LDA Linear Discriminant Analysis used by Cooley and Barber (Cooley Paul & Barber David, 2003) and i) ISODATA classification technique used by Do et al (2018); Mitra et al (2017); Sekovski et al (Ivan et al, 2014); and Annibale et al (Annibale Guariglia et al, 2009). On the other hand, in manual category belong a) the on-screen digitizing (Pantanahiran, 2019;Asib et al, 2018;Senevirathna et al, 2018;Carolina et al, 2018;George et al, 2015;Prasita, 2015;Andredaki et al, 2014;Kim et al, 2013;El-Asmar and Hereher2011;Tateishi 2007;Hervé et al, 2005;Fromard et al, 2004;Aris et al, 2008;Faik et al, 2008) and b) Differential Global Positioning System (DGPS) field measurements (Addo, 2009;Andredaki et al, 2014;Annibale Guariglia et al, 2009;Antonello et al, 2013;Elsner Paul et al, 2015;Fe...…”

“…Apart from the optical satellite data many researchers used Radar data (Mohammad et al, 2018;Ferdinando et al, 2018;Vandebroek et al, 2017;Francesca et al, 2016;Fugara et al, 2011;Hervé et al, 2005;Cooley Paul & Barber David, 2003). Radar scans the Earth's surface operating at the microwave region of the electromagnetic spectrum and its results depended on the backscattering coefficient on the physical properties of the observed surfaces.…”

“…used a combination of Landsat images and a Temporal Differentiate Image (TDI), created by three radar images (SAR.PRI/ ERS-2) in order to investigate the shoreline changes in Sperchios River, Greece. Trebossen et al(Hervé et al, 2005) used radar images in a study of coastal development and monitoring coastal risks off the coast of French Guiana. Al_Fugara et al (2011) used RADARSAT-1 images for monitoring coastal evolution of shoreline on Kuala Terrengganu of Malaysia.…”

Spatio-temporal analysis of Lençóis Maranhenses between 1984 and 2014 using orbital remote sensing

“…Segundo Morain (1998), o surgimento do sensoriamento remoto proporcionou uma nova compreensão do ambiente, possibilitando se desenvolver estudos em diversas escalas geométricas e de tempo, nas mais diferentes regiões do planeta, sendo uma ferramenta que possibilita estudos em diferentes áreas do conhecimento, dentre as quais se destacam as geomorfológicas (Hugenholtz et al, 2012;Aydda;Algouti, 2014), geológicas (Mohamed;Verstraeten, 2012), climatológicas (Janke, 2002) e planejamentos socioambientais (Sparavigna, 2013). Em estudos de cunho ambiental, a análise multitemporal a partir das imagens de sensores remotos consiste em uma excelente ferramenta para auxiliar estudos geomorfológicos costeiros, ao estender informações pontuais de uma área para um contexto histórico (Trebossen et al, 2005). A análise multitemporal utiliza imagens de satélite de determinada área em períodos distintos, não se restringindo a usar imagens de um mesmo sensor na coleta de informações (Moreira, 2011).…”