APPLICATION OF HISTORICAL DATA FROM SATELLITE IMAGERY TO IMPROVE UNDERSTANDING OF COMPLEX NEARSHORE DYNAMICS

Abstract

Collection of nearshore data such as bathymetry and benthic surveys are a requirement to all coastal projects. Typically, surveys are conducted in advance of a modelling exercise so as to replicate in-situ and existing conditions. These surveys only show one snapshot in time and as such do not represent conditions that are out of equilibrium from either seasonal or long-term changes. In these locations, an assessment of a timeseries of surveys would benefit the understanding of nearshore coastal dynamics. However, timeseries of nearshore data are seldom available. Traditional coastal survey technology, e.g., bathymetry from acoustic means or airborne lidar, are expensive and time consuming, and as such they are rarely conducted on a regular basis. Satellite data offers a novel solution by allowing access to very high-resolution data generated over a 20-year time period stored in easily accessible archives, including a convenient web-based application. This paper describes the application of historical satellite data to understand coastal change to a dynamic sand spit feature in Pigeon Point in Southwest Tobago.