Use of Remotely Sensed Imagery for Coastal Management: A Guide for Coastal Decision Makers

Use of remote sensing imagery has become essential for effective coastal management, as nearshore environments continue to experience increasing commercial and residential development pressures. Imagery provides resource managers with the capability to evaluate conditions such as distributions of vegetation/invasive species, water quality, and coastal development patterns. In recent years the choices of available imagery have rapidly increased to include various types of multi- and hyperspectral images acquired from both satellite and aerial platforms. Choosing the most appropriate imagery for a specific application often involves tradeoffs between spatial and spectral resolution, and between image resolution and cost considerations. In general, increased spatial resolution is gained at the expense of spectral resolution, and vice versa. Satellite sensors can image large areas, but at the expense of spatial detail, whereas airborne sensors can image smaller areas at higher resolutions, but require collection of much larger amounts of data. Issues with spatial/spectral resolution and the increasing technical complexity of available imagery present challenges that can hinder its effective use by coastal decision makers. We discuss various types of imagery for coastal management and advantages and disadvantages of each in coastal applications. Special attention is given to differences between satellite and aerial imagery, spatial and spectral resolution, and deep-ocean and estuarine environments, and how these distinctions influence data analysis and product development. We present a case study comparing and contrasting the use of hyperspectral imagery acquired in the Apalachicola Bay, Florida with commercially available Digital Orthoquad (DOQ) color-infrared imagery to examine habitat and land use patterns.