Satellite Application Algorithms for Coastal and Marine Spatial Planning in the Pacific Island Countries: A Case Study in Funafuti, Tuvalu

Abstract

The coastal region of the Pacific Island countries influenced by several driving forces and subjected to continuous erosion/accretion. To assess the changes, decision ready tools and management solutions of Coastal and Marine Spatial Planning (CMSP) are needed. Therefore, the project entitled ‘Development of decision ready tools to support Coastal and Marine Spatial Planning’ aims to develop various decision ready tools by using multiple satellite platforms to aid in the sustainable management of coastal regions. It includes the coastline extraction, land use classification and wave properties retrieval tools. For this work, Tuvalu is selected as the study area and the coastline, land use class and wave properties around Funafuti, the capital of Tuvalu are mapped. An algorithm is developed for high resolution WorldView-2 image to extract the coastline. In the course of coastline extraction, mapping of land use is also conducted where the land use is classified into three classes. Additionally, Landsat 8 and Sentinel-2 images are used to extract the Funafuti atolls coastline. Furthermore, an algorithm is developed to retrieve the wave properties in the vicinity of Funafuti from the Landsat 8 image. However, due to the complex characteristics of the coastal area of Funafuti atoll, it is challenging to extract the coastline from the WorldView-2 image as shallow water area shows similar reflectance as like as sediments. Besides, the similarity in the reflectance of shallow water area and sediments generate inaccurate results in the case of land use classification. Therefore, the algorithm will be improved by modifying the reflectance-based condition to generate a distinct difference between the shallow water area and sediments. Besides, altimetry data from ICESat-2 will be used to obtain the elevation information of coast area. Furthermore, Sentinel-2 images will be used to extract the wave properties around Funafuti. The outcomes of this work offer a great advantage in the case of decision making by providing maps and accurate information about the coastal environment.