GIS 기법을 이용한 동강 유역분지의 지형 특성 분석 = The Analysis of the Topographical Characteristics in the Dong-River Watershed, Using GIS Methods

다국어 초록 (Multilingual Abstract)

The Dong-River is one of the big upper reach branch on the South Han-river. In this study, the geological and the topographical characteristics of the watershed were analysed. We used the DTED level 1, digital geology map and GIS software program, ARC/IMFO. ① The watershed is composed mostly paleozoic geology and its area ratio is 66 percentage. The NNE-SSW strike, symmetrical arrangement of the sedimentary rocks is originated that the area has been folded and then dissected. ② The mean altitude of the Dong-River Watershed is 738 meters, The mean relief energy on the 1 by 1 kilometer mesh is 270 meters and the hypsometric integral is 0.48. By the above all characteristics, we concluded that the terrain of the Dong-River Watershed is very rough and is in the maturity stage of the erosion cycles. ③ The landscape of permian sand stone(Gobangsan-Series) districts is nagged with high altitude, high relief energy, steep slope and low drainage density. But the Daebo-Granite is farmed the high-level planation surfaces that it has high altitude, relatively low relief energy, gentle slope and high drainage density. The limestone(Greate Limestone Series) districts saw relatively low altitude but the relief energy in high. The valleys wall on the limestone district are especially step and it is mostly above 25 degrees. But inter valley areas are relatively gentle and are recognised two level planational surfaces, 700∼800 meters and 1,000∼1,100 meters in altitude. ④ If the dam(Yongwoal) is constructed, we must regard the possibility of serious disaster, that is, as the water rises it will infiltrate into the limestone cracks, loosen valley wall blocks, finally generate huge block fall.