Monitoring vegetation biomass of a coastal ecosystem using multidate optical satellite data

Abstract

In order to effectively protect coastal ecosystems, objective information on the structural and functional characteristics of these systems must be obtained through regular monitoring. In recent years, more advanced technologies, such as satellite remote sensing, have arisen which are being utilized for the monitoring and management of coastal ecosystems in general, and vegetation in particular. This paper presents the results from monitoring the vegetation biomass of the Koycegiz Lagoon area, declared as a Specially Protected Area by the Turkish Government, using multi-temporal satellite imagery. Several problems need to be overcome when using imagery from different dates or from different sensors. These include; image registration, atmospheric variability, and, often, the lack of historical ground data. Furthermore, for monitoring purposes, techniques to overcome these problems should be robust and automatic allowing the database to be upgraded easily. The procedures we have developed include automatic registration (to subpixel accuracy), atmospheric normalization, and vegetation index (VI) calibration components. This was tested on multidate (1984, 1988, 1991, 1995 and 1996) LANDSAT-TM data. From this adjusted data set the performance of different vegetation indices, in this coastal environment was examined, and the vegetation trends analyzed.