Laplacian of Gaussianフィルタによる地形表現手法について

摘要

航空機搭載型LiDARの普及やコンピュータ処理能 力の向上によって，立体感を持った詳細な地形特徴を 表現することが実用的に行われるようになってきた。 そして，このような地形表現は，人間の判断力を用い て地形区分をする地形判読において有用であるとして，広く活用されてきた。急峻な地形を持つ我が国で は大きな斜面災害が各地で頻発しており，なかでも風 化した深層岩盤が崩れ落ちる深層崩壊に注目が集まっている。%This paper reports the representation method of topographic features using detail digital elevation model. In previous research, topographic features index that compounded the over-ground and under-ground openness index (Yokoyama et al., 1999) and slope gradation map was used as well. However, these methods have some problems.such as, restriction of its usage by the patent and complicated calculating processes. Therefore, many users are not able to use it for topographical feature interpretation work freely and easily.rnThe proposed method in this report, adopting Laplacian of Gaussian filtering used in the machine vision technology, is able to calculate the same effect as in the openness index, without any concern of patent restriction. As this proposed method can be used for making landslide inventory map, consideration of road network or planning for forest resources management, it is expected to be used in various fields by various users.