Quasi-three-dimensional Slope Runoff Model Taking Account of Topography of a Natural Watershed, and Automatic Genaration of a Basin Model

本研究以建立考虑流域地形的分布式流域径流模型为目的，开发了基于栅格的DEM数据生成系统、流域地貌信息系统和流域河网地貌特征分析自动数据处理系统.一个基于格网的DEM数据生成系统一个使用图像扫描仪生成基于格网的DEM（数字高程模型）数据的系统。该系统在微机上工作，通过对数据的处理，使图象数据只包括地形等高线。与运营商互动。利用这些影像数据，生成格网DEM数据.流域地貌信息系统BGIS（Basin Geomorphic Information System）是一个应用于水文模拟的地理信息系统，它采用TIN-DEM（Triangulated Irregular Network - Digital Elevation Model）数据结构建立流域模型。BGIS由四个模块组成，（1）一个模块，用于建立一个基于三角形的地形模型，（2）一个模块，用于连接孤立的山谷段到一个通道网络，（3）一个模块，用于摆脱坑，（4）一个模块，用于细分三角形面。利用BGIS处理后的数据集，可以对水系中的任意河段进行流域源区的划分。BGIS应用于荒川。实验盆地（0.184km^2）和稻川盆地（54.0km^2）。流域、水系地貌特征分析自动数据处理系统该系统可以分析地貌特征（海拔、坡向、坡度、上坡轴和水流路径长度），并在个人计算机上显示这些特征的二维分布。

In this research, in order to make a distributed rainfall-runoff model which takes account of a topography of a natural watershed, a grid based DEM data producing system, a basin geomorphic information system, axid an automatic data processing system for analysis of geomophic features of drainage basins and channel networks axe developed.1. A grid based DEM data producing systemA system for producing a grid based DEMs(Digital Elevation Models)data using an image scanner is developed. This system works OIL a personal computer and makes an image data included only topographic contour lines by processing the data. interractively with an operator. Using this image data, a grid DEM data is generated.2. a Basin Geomorphic Information SystemA geographic information system in hydrologic modeling, BGIS(Basin Geomorphic Information System)is presented for modelilig a river basin using a TIN-DEM(Triangulated Irregular Network - Digital Elevation Model)data structure. BGIS is made up by four modules, (1)a module for making a triangle based terrain model, (2)a module for joining isolated valley segments to a channel network, (3)a module for getting rid of pits, (4)a module for subdividing triangular facets. Using a data set processed with BGIS, a watershed source area for any segments in a stream network can be delineated. BGIS was applied for Arakawa. Experimental Basin(0.184km^2 and Inakawa basin(54.0km^2).3. An automatic data processing system for analysis of geomorphic features of drainage basins and channel networks The system makes it possible to analyze geomorphologic feartures(altitude, aspect, slope, upslope axea and flow path length)and to show those distribution two-dimensionally on a personal computer.