Geomorphological modelling of tropical marine landscapes: Optical remote sensing, patches and spatial statistics

The relation of structural responses to underlying functional processes at the landscape scale helps develop our understanding of geomorphological phenomena at the coastline. This paper demonstrates how a habitat map derived from remotely sensed imagery was used as the basis for the development of an explanatory model to investigate factors influencing the linearity of alternating carbonate sand and seagrass patches on a reef flat in the Seychelles, western Indian Ocean. In combination with techniques established in landscape ecology for interrogating broad scale processes and spatial statistical procedures that bring geography explicitly into the analysis, an emergent framework for the quantification and investigation of geomorphological processes is illustrated. The combined influence of adjacent spur and groove amplitude and incident wave power accounted for 81% of the variation in sand and seagrass patch linearity across the habitat map. A series of steps in model development are examined, including observation, measurement, experimentation and interpretation. These steps both define and permit an empirical approach to geomorphology and the case study highlights how each can be achieved by adopting an interdisciplinary framework.