Creation of the valley information GIS database for Nuta River valley in Hiroshima [Japan]: Creation of the GIS database using the digital map
2005
Yoshisako, H.(National Inst. for Rural Engineering, Tsukuba, Ibaraki (Japan)) | Ogawa, S. | Shima, T. | Ohnishi, R.
In the water management analysis for a wide area, various kinds of geographic information are needed in analysis work. When performing the simulation by the mathematical model especially, geographic information, such as a waterway, and a reservoir, an inflow region to a waterway, is required because of creation of a mathematical model. When creating a mathematical model for a wide area, it is a subject to process geographic information efficiently. This report introduced the structure and the construction of the valley information GIS database which constituted some simulators evaluating the flood mitigation function at the time of the heavy rain in the area where a reservoir exists mostly. In addition, the proposal of the creation method of the data item which cannot be created from geographic information, and the estimated method of lack data was introduced. The error by the dryness and moisture of paper does not generate the method of creating data on a screen by making into a background picture the digital map 25000 (map image) fixed as a space data base. By this method, after displaying a background picture for the most suitable magnification on work, an input is possible. As compared with the conventional method of creating GIS data using a digitizer etc., improvement in input accuracy is expectative. By use of digital map 50m mesh (altitude), an input of a contour line becomes unnecessary. The increase in efficiency of an input is realized.
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