| Titre | SAR backscatter and InSAR coherence for monitoring wetland extent, flood pulse and vegetation: a study of the Amazon lowland |
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| Auteur | Canisius, F; Brisco, B; Murnaghan, K; Van Der Kooij, M; Keizer, E |
| Source | Remote Sensing vol. 11, issue 6, 720, 2019 p. 1-18, https://doi.org/10.3390/rs11060720  Accès ouvert |
| Image |  |
| Année | 2019 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20190167 |
| Éditeur | MDPI AG |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.3390/rs11060720 |
| Media | en ligne; numérique |
| Formats | pdf (Adobe® Reader®); html |
| Région | Amazon River; Santarém City; Tapajós River |
| Lat/Long OENS | -55.5000 -54.2500 -1.2500 -2.7500 |
| Sujets | terres humides; inondations; plaines d'inondation; végétation; télédétection; imagerie par satellite; eaux de surface; niveaux d'eau; Hydrologie; hydrogéologie; géophysique; Sciences et technologie;
Nature et environnement |
| Illustrations | cartes de localisation; images satellitaires; organigrammes; cartes géolscientiques généralisées; graphiques; séries chronologiques; graphique à barres |
| Programme | Science de la télédétection spatiale |
| Diffusé | 2019 03 26 |
| Résumé | (disponible en anglais seulement)
Synthetic aperture radar (SAR) data have been identified as a potential source of information for monitoring surface water, including open water and flooded
vegetation, in frequent time intervals, which is very significant for flood mapping applications. The SAR specular reflectance separates open water and land surface, and its canopy penetration capability allows enhanced backscatter from flooded
vegetation. Further, under certain conditions, the SAR signal from flooded vegetation may remain coherent between two acquisitions, which can be exploited using the InSAR technique. With these SAR capabilities in mind, this study examines the use of
multi-temporal RADARSAT-2 C band SAR intensity and coherence components to monitor wetland extent, inundation and vegetation of a tropical wetland, such as Amazon lowland. For this study, 22 multi-temporal RADARSAT-2 images (21 pairs) were used for
InSAR processing and the pairs in the low water stage (November, December) showed high coherence over the wetland areas. The three-year intensity stack was used for assessing wetland boundary, inundation extent, flood pulse, hydroperiod, and wetland
vegetation. In addition to the intensity, derived coherence was used for classifying wetland vegetation. Wetland vegetation types were successfully classified with 86% accuracy using the statistical parameters derived from the multi-temporal
intensity and coherence data stacks. We have found that in addition to SAR intensity, coherence provided information about wetland vegetation. In the next year, the Canadian RADARSAT Constellation Mission (RCM), will provide more data with frequent
revisits, enhancing the application of SAR intensity and coherence for monitoring these types of wetlands at large scales. |
| Sommaire | (Résumé en langage clair et simple, non publié)
L'objectif principal de cette étude est d'évaluer l'utilisation des informations fournies par les satellites radar pour caractériser les zones
humides de la région amazonienne de la plaine d'inondation tropicale pendant les saisons sèche et humide. L'étude a montré que le satellite canadien RADARSAT-2 peut surveiller l'étendue des zones humides de l'Amazonie, les inondations et la
végétation. Les informations sur les changements sont très utiles pour comprendre le cycle de l'eau, le changement climatique, la biodiversité et les populations de poissons ainsi que les rendements de pêche associés. Les connaissances acquises grâce
à cette étude seront utilisées pour proposer une méthodologie qui pourrait conduire à une utilisation opérationnelle des images radar des satellites pour la surveillance des zones humides. |
| GEOSCAN ID | 315324 |
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