• Journal of the Korean association of regional geographers
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• v.13 no.4
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• pp.409-421
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• 2007

The purpose of this paper is to consider the formation processes and depositional conditions of bars formed at the upper-stream part of Sayeon Dam since Sayeon Dam construction in 1964. Results of analyzing the shape characteristics of bars and their sediment grain size distribution are as follow: Firstly, bars are able to categorized as subaqueous bars (A, B), mid-channel bars(C, D), and tributary side-bars(E). Secondly, the outline of bars has longish along the flow path, and their height lowers more and more going towards downstream. Also the height of bar surface tend to heighten from flow path to mountain slope. However, the near part of A is comparatively higher than its distant part, A is defined as a subaqueous natural levee and back swamp. Thirdly, the average particle size of A and B become smaller toward mountain slope. In transportation style, ratio of suspended load become higher toward mountain slope. Fourthly, sorting is worse to very worse according with lake's random changable water level. Fifthly, bar A and B were formed by vertical sedimentation of sediments according as sediments transported along flow path in the subaqueous conditions were spreaded out of flow path. C and D were formed by bed load as flood level lowered. And E was formed by vertical sedimentation while stream flow stopped in tributary's mouth areas with the water level heightening.

• Journal of the Korean association of regional geographers
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• v.22 no.1
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• pp.211-224
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• 2016

Natural lakes are estimated in variety with that's function or value depending on age environment or geographical characteristics. There are many kind of natural lakes, but the kind of natural lake is limited in rivers in korea flowing into East Sea. However, Yeonho lake in Uljin has different geographical characteristics with oxbow lake or lagoon which is common in korea's river flowing into East Sea. Therefore the purpose of this study is to analyze geographical characteristics due to the process of Yeonho's formation. Further more research for protecting wetland is needed to adequately preserve, depending on the geomorpologic process. To analyze geographical characteristics, it was essential to compare and analyze topographical map of 1918 1956 2012 and I pictured estinated line of bedrock and longitudinal section of Nam-dae cheon(Riv) Yeonho cheon(Riv). In addition, I denoted flooded areas through design flood level of Nam-dae cheon(Riv) Yeonho cheon(Riv) and analyzed particle size distribution of deposited sediment due to consider deposit environment. The results of study are as follows. In conclusion, Yeonho lake is floodbasin which was not researched at river flowing into East Sea. Through this study, my opinion is that floodbasin can be formed in the river that is steep and short. I argue that preservation methods will be seeked by geomorphologic process of floodbasin and development of downtown.

• The Korean Journal of Quaternary Research
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• v.31 no.2
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• pp.13-22
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• 2017

The age of the Sorori old fluvial deposits is assumed as old as Last Interglacial(MIS 5) when appying the thalassostatic terrace formation in mid- to downstream Keum river basin, while the young fluvial deposits are interpreted to be formed since the post-LGM(last glacial maximum), including both the Bølling-Allerød (B/A) Interstadial(12,700~14,700 cal-yrBP), and the Younger Dryas Stadial(11,700~12,900 cal-yrBP). The wild rice seed like Oryza rufipogon found in the middle organic muds of the young fluvial deposits dated after about 15,000 cal-yrsBP, when the transition from the subalpine conifer forest to the deciduous broad-leaved forest was conspicuously evidenced in the upper part of OC-2 palynofloral zone of the in Cheonju Sorori site, In particular the OC-2 palynofloral zone ranging towards the upper part of middle organic muds(peaty muds) is interpreted to be formed in the B/A Interstadial. It is regarded that Cheongju Sorori rice seeds are associated with warm palynological evidences and backswamp insects during the Lastest Glacial, showing appearance of relatively warm climate similar to the present.