The Use of Remote Sensing for Coral Reef Mapping in Support of Integrated Coastal Zone Management: A Case Study in the NW Red Sea - Volume I

摘要

Worldwide, coral reefs are rapidly degrading due to the combined negative effects of human activities and global change. Even though the Red Sea is a very suitable natural environment for coral reef growth, their status also has rapidly deteriorated since the 1970s. Coral reefs are especially affected in the NW Red Sea, primarily due to coastal development projects supporting the booming tourism industry. Integrated coastal zone management (ICZM), therefore, is urgently needed to protect the coral reefs and conserve these valuable natural resources for future generations. Effective ICZM necessitates sound baseline information concerning the current status of the coral reefs and the actual human activities taking place, as well as a tool to monitor changes in both elements. Fulfilling these requirements using in situ observations alone is both time- and labour-intensive and, therefore, often financially too demanding, especially for developing countries. Here, remote sensing may bring the solution as it synoptically collects data over large areas in a cost-efficient way. This work has proven the usefulness of passive, optical remote sensing from spaceborne platforms to collect and monitor the required data and support an effective ICZM. Based on Landsat 7 ETM+ and QuickBird data, accurate information has been collected on the bathymetric structure of the coral reef seabed, its geomorphological zonation, and the distribution of the main marine coastal habitats. The possibility to monitor changes in these elements as well as in the coastal development has also been confirmed. These remote sensing derived products have subsequently been analysed and integrated with auxiliary datasets in a GIS to develop valuable decision-support products such as a risk assessment map and a multi-use marine protected area zoning plan. To support ICZM, remote sensing is best integrated in a multi-level sampling approach in which detailed in situ observations are complemented with more broad-scale, regional information derived from remote sensing data analysis. As such, information-based decisions can be made, augmenting the success of the ICZM. This not only counts for the specific study area but is likely necessary for the sustainable development of coral reef coastal zones worldwide.