Abstract
In order to monitor changes caused by local and global human actions to a coral reef ecosystem, we `sea-truthed' a natural color Landsat Thematic Mapper (TM) image prepared for a coastal region of the northwestern Dominican Republic and recorded average water depth, precise positions, and bottom types (seagrass n = 15 sites, coral reef n = 10 sites, and sand n = 6 sites). There were no significant differences in depth for the bottom type groups, which ranged from 0-16.1 m (0-52.7 ft). Sand > seagrass > coral in mean radiance for the three Landsat TM visible bands (TM 1, TM 2, TM 3); sand bottom sites had significantly greater radiance than seagrass and coral sites in TM 1 only. Mean radiance of seagrass and coral reef sites did not differ significantly in any band. A multivariate analysis of variance using all three bands gave similar results. A ratio of the green/blue bands (TM 2/TM 1) showed there was a spectral shift associated with increasing depth but not bottom type. Due to small-scale patchiness (<30 m×30 m), seagrass and coral areas were difficult to distinguish, but sandy areas can be mapped with this method.
Original language | English (US) |
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Pages (from-to) | 809-816 |
Number of pages | 8 |
Journal | Proceedings of SPIE - The International Society for Optical Engineering |
Volume | 1930 |
Issue number | pt 2 |
State | Published - 1992 |
Externally published | Yes |
Event | Proceedings of the 1st Thematic Conference on Remote Sensing for Marine and Coastal Environments - New Orleans, LA, USA Duration: Jun 15 1992 → Jun 17 1992 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Computer Science Applications
- Applied Mathematics
- Electrical and Electronic Engineering