A Research Note on Natural Reclamation Processes that Support Mangrove Biodiversity Spheres: Sedimentation in Three Major River Deltas in Northwestern Luzon Using Aerial Imagery

River deltaic regions feature natural reclamation processes that generate mangrove-viable environments. The new sediments that fan out and are reconcentrated by coastal waves become newer land extensions or even river islands and islets that become a spawning ground for mangrove ecosystems. The temporal dimension of these changes is showcased through case studies that tap on multiscalar remote sensing and geographic information systems (RS-GIS) tools (micro, meso, and macro) in studying mangrove ecosystems. In this research note, I provide a contemporary historical record of the sedimentation in three river deltas in Northwestern Luzon: the Bauang/Naguilian, Aringay, and Amburayan Rivers. As a baseline, topographic maps from the NAMRIA 711 series at 1:50000 scale are used dating to aerial photography in the 1960s to 70s. These historical imageries are then contrasted to April 2013 WorldView 2 satellite (Digital Globe Foundation) imagery at 2 meters spatial resolution. The resulting output is a geographic information systems (GIS) shapefile of new sedimentation that has reclaimed part of the sea or even part of the river conduits. This macroscale output was then compared to more macro to meso scalar data taken from a Consumer Off the Shelf Remotely Piloted Aircraft Systems (COTS-RPAS). Special focus will be given to the mangrove ecosystem that has made these silt accumulations a new home.