An Analysis of the Hydrological Runoff System Based on the Digital National Land Information

本研究利用通用计算机和建设部地质调查所发布的数字国土信息系统开发了两个系统。一个是流域和河网地貌分析的自动数据处理系统，另一个是考虑天然分水岭地形的流域模型自动生成系统。流域和河网地貌特征分析自动数据处理系统与传统方法相比，该系统可以更客观、更自动化地分析地貌特征，并显示流域的三维结构，并自动计算基于Horton-Strahler河数和连接量的各种特征值。计算并比较了10个流域(190-870 km2)的这些值。考虑天然流域地形的流域模型自动生成系统在该系统中，流域的地形表面由基于网格的数字高程模型(DEM)生成的三角剖分单元来表示。将被三角形单元覆盖的流域划分为坡元，计算每个坡元的径流高度，并利用数字国土信息将该方法应用于伊纳河流域，验证了该方法的有效性。

In this research, two systems using general purpose computers and the Digital National Land Information released by the Geological Surveying Institute, the Ministry of Construction are developed. One is an automatic data processing system for analysis of geomorphologic features of drainage basins and channel networks, and the other is an automatic generating system for modeling of drainage basins which consider the topography of natural watershed.1. Automatic data processing system for analysis of geomorphologic features of drainage basins and channel networksThe system makes it possible to analyze the geomorphologic features more objectively and automatically than a conventional method and to show a three-dimensional structure of a basin, and various characteristic values based on the Horton-Strahler stream number and link magnitude are calculated automatically. These values in ten river basins (190-870 Km^2) are calculated and compared.2. Automatic generating system for modeling of drainage basins which consider the topography of natural watershedIn this system, the topographic surface of a basin is represented by trianguler elements which are generated from grid based DEM (Digital Elevation model). A basin coverd with triangular elements is divided into slope elements and runoff height of every slope element is calculated.This method is applied to the Ina River Basin using the Digital National Land Information, and the availability of this method is confirmed.