国土数値情報を用いた水文地形解析に関する基礎的研究

Abstract

This paper describes automatic data processing systems for analysis ofgeomorphologic features of drainage basins and channel networks, using generalpurpose computers and the Digital National Land Information released by theGeological Surveying Institute, the Ministry of Construction. The systems formerlyproposed by the authors are improved and expanded. The method of analysis, which is called the GM method in this paper, makes it possible to analyze thegeomorphologic features more objectively and automatically than conventionalmethods and to show the three-dimensional structure of the basins. The authorsgive a general procedure of the analysis and apply it to ten river basins (190-870km2) in Japan. Various characteristic values based on the Horton-Strahler streamnumber and the link magnitude are obtained and compared. The threshold valuedefining the first-order stream is also discussed.