Investigation and analysis on current status of the tsunami-stricken coastal forest using high-resolution images prepared by unmanned aerial vehicle

Abstract

We investigated the current conditions of trees that were affected by the recent huge tsunami in the coastal forest of Iwanuma City, Miyagi Prefecture, Japan, using high-resolution images prepared by unmanned aerial vehicle and by conducting field survey. The difference in canopy textures on the images could help us distinguish between Pinus thunbergii and P. densiflora, whereas the distinction between species was difficult among broadleaf trees. The vegetation from the coast inward comprised 1) Robinia pseudoacacia, 2) P. thunbergii, 3) P. densiflora, 4) Cerasus jamasakura-P. densiflora mixed woods, or 4) wet grassland. The number of P. thunbergii increased abruptly at around 280 m from the coastline because of the microtopography of the beach ridge. Distribution of P. thunbergii and P. densiflora was strongly influenced by planting and vegetation management rather than the salt tolerance of those two species on the backside of the coastal forest.