• Journal of the Korean Geographical Society
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• v.49 no.1
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• pp.1-17
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• 2014

This study estimates geomorphological processes of fluvial terraces by uplifts and bedrock features, by the analyses of topography, distribution, formation age and incision rate of fluvial terraces using Gwang-cheon River in Uljin, Namdae-cheon River in Pyeonghae and Osip-cheon River in Yeongdeok located in the southern Taebaek Mountain Range. The tectonic and climatic terraces I in the upper reaches of Gwang-cheon River with an altitude from riverbed of 9~12m indicate the formation age of MIS 2 with a incision rate of 0.40m/ka. However, the tectonic and climatic terraces I in the upper reaches of Osip-cheon River with an altitude from riverbed of 7~10m show the formation age of MIS 3 with an incision rate of 0.10m/ka. These results suggest that the uplift rate in the Gwang-cheon River basin is likely to be higher than that in the Osip-cheon River basin. Unlike the lower reaches of Osip-cheon River, the thalassostatic terraces are not found in the lower reaches of Gwang-cheon River, because the basin has low maintainable ability of landforms in river valley due to high uplift rate and bedrock properties resistant to weathering and erosion. On the other hand, the lowest tectonic and climatic terraces in the study areas indicate different formative ages and the terraces during the cooling stage in interglacial as well as during interstadial are also found. Therefore, this study suggests that chronological method for fluvial terrace by the previous developmental model of climatic terrace should be reconsidered.

• Journal of the Korean Geographical Society
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• v.39 no.6 s.105
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• pp.833-844
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• 2004

In Chugaryeong rift valley, lava plateau formation by the fissure eruption had vanished original landforms and effected on drainage derangement and revision. 4 rivers including Namdae-cheon, Bukhan-gang, Imjin-gang and Hantan-gang watersheds have shared Cheolwon-Pyeonggang lava plateau, that is, ownerless watershed. Main agency of the dividing process are central-eruption volcanic peaks such as Orisan(453m) and 680 Peak. Especially, Orisan has played the role of divide point for 4 watersheds. In the lower-relief plateau zone, complex drainage system have caused continually river capture between neighboring watersheds. In more elevated range slope, river capture have proceeded to headward erosion. Hydrogeomorphologically, lava-filled valley has initiated decrease of the original size of flood plain, maybe, causing higher capability of inundation by heavy rains, and then more active dissection of lava plateau layer.

• Journal of Korea Water Resources Association
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• v.38 no.5 s.154
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• pp.391-399
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• 2005

The purpose of this study is to evaluate hydrological impact by the land cover change of typhoon damage. For the typhoon RUSA (rainfall 1,402 mm) occurred in 2002 (August $31\;{\sim}$ September 1), satellite images of Landsat 7 ETM+ of September 29, 2000 and Landsat 5 TM of September 11, 2002 were selected, and each land cover was classified for Namdae-cheon watershed $192.7km^2$ located in the middle-eastern part of Korea Peninsula. SCS unit hydrograph for watershed runoff and Muskingum for streamflow routing of WMS HEC-1 was adopted. 30m resolution DEM & hydrological soil group using 1:50,000 soil map were prepared. The model was calibrated using three available data of storm events of 1985 to 1988 based on 1985 land cover condition. To predict the streamflow change by damaged land cover condition, rainfall of 50 years to 500 years frequency were generated using 2nd quantile of Huff method. The damaged land cover condition treated as bare soil surface increased streamflow of $50.1\;m^3/sec$ for 50 years rainfall frequency and $67.6\;m^3/sec$ for 500 years rainfall frequency based on AMC-I condition. There may be some speedy treatment by the government for the next coming typhoon damage.

• Korean Journal of Environmental Agriculture
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• v.16 no.1
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• pp.19-24
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• 1997

This studies was carried out to investigate the soil contamination and water quality affected by agricultural activities in the Keum river Districts. Soil pH of the Keum river districts were $5.56{\sim}7.09$ in Keum river headwater and Namdae-cheon but that of Keumgang-lake were $5.07{\sim}7.21$ because of the cattle shed and industrial complex around. Total nitrogen contents of soils were found difference as period of fertilizer application. Total phosphorous content of soils no difference were found between the headwater and Keumgang-lake. Heavy metal contents of soils were natural background level. Water pH of the Keum river districts ranged from 6.59 to 7.80 and COD was maintain below 1.0 mg/L. Total nitrogen content affected by a livestock wastes and sewage water were the higher than that of others and total phosphorous content showed below 0.5 mg/L. Nitrate nitrogen and ortho-phosphate contents were very high according to the influence a livestock waste and sewage water in headwater region of the Keum river partly. Chlorine and sulfate contents were high according to the influence of sea water invasion. Heavy metal contents of waters were natural background level.