Assessing seasonal vegetation change in coastal wetlands with airborne remote sensing: an outline methodology

Abstract

Airborne remote sensing offers high-density, spatially-averaged synoptic samples of radiation reflected from a surface which can be used to infer ecological processes and community composition. Unfortunately, the cost of the overheads in terms of time and resources, and scheduling constraints when deriving quantitative information have limited its use in operational monitoring programs. When the changes in reflected radiation related to the phenomenon under investigation are large, only minimal low-cost processing is required to identify ecosystem modification if high frequency multi-temporal imagery can be combined with expert knowledge. This methodology is likely to be of particular value in coastal environments where access for conventional measurements is restricted and changes in sensitive tidal wetlands may provide an early indicator of changing natural processes and/or human impact. Regularly acquired airborne remotely sensed imagery has been used in a reconnaissance study to identify and map seasonal vegetation patterns on intertidal surfaces in back barrier environments on the North Norfolk coast, England, U.K. The development of an operational system for coastal zone management is discussed.