• Journal of the Korean Geographical Society
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• v.46 no.3
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• pp.304-318
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• 2011

The types, distributional and shape properties of abandoned channels in Korea are classified and examined. There are 409 abandoned channels in Korea and they can be classified into the 6 types such as the incised meander cutoff, stream piracy, distributary, artificial incised meander neck-cutoff, channel straightening of free meander and distributary streams. The abandoned channels by incised meander neck-cutoff showing the most frequency with 266, have the topographical properties of high altitude and steep relief and frequently distribute in Gangwon and Gyeonbuk Province and in the upper reaches of main stream of Nakdong-River, and Dal-River and Pyeongchang-River, tributaries of Namhan-River. The most frequency areas of abandoned channels by distributary, channel straightening of free meander and distributary streams are the lower reaches of Namhan-River and main stream in the lower reaches of Nakdong-River, Mangyeong-River and Yeongsan-River, and Geumho-River, respectively. The abandoned channles by incised meandering neck-cutoff and stream piracy are relatively used as farmlands or forests due to the high altitude and relative altitude from the river bed.

• Journal of the Korean association of regional geographers
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• v.10 no.4
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• pp.689-697
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• 2004

The Main results of this paper about the river channel of Shincheon(river) are as follows: First, the argument that Shincheon had a different river channel from existing one before 1778 would be wrong. Second, the origin of the place name, Shincheon has been traced up to the year of 1778 also would be wrong. Third, Daegucheon(river) regarded as a distributary of Shincheon would be the different stream originated from Samjeong valley and near by hills. Forth, Daegucheon had mostly dried up and disappeared during the Japanese colonial times while part of Daegucheon had changed its channel into Icheoncheon(river). Fifth, the river channel of Shincheon since the historic age has been unchanged.

• Explosives and Blasting
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• v.18 no.3
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• pp.99-106
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• 2000

The geology of Nogsan industrial estate area, Pusan, Korea consists mainly of andesitic rocks, rhyolitic rocks and hornblende granite. They are then intruded by basic and acidic dikes. All of the igneous activities in this area are in Cretaceous time, that is the lower part of Silla group in Gyoungsang basin. Andesitic volcanic rocks are distributed in two separate basines: Saengok basin and Doodong basin. Although both basines contain andesite and andesitic breccia(Kab), younger andesitic activity was more active to the western Doodong basin giving very little influence on the eastern Saengok basin. Sediments in the area are quarternaly alluvium and colluvium. Alluvium is very thick and consists mainly of silt and clay deposited as delta deposits at the mouth of Nakdong river. Colluvium in the area is short distributary channel deposits. The area is largely filled with socks and sediments to build industrial estates especially on the delta deposits at Shinhodong area and on the shoreline mud bed between Yongwondong and Shinhodong. A careful investigation to avoid the possibility of a large scale mud flow is suggested because it could be trigered by many reason such as an earthquake or a flood on the land where a heavily loaded salt-water may soaked into the muddy bed lying on the granitic basement gently dipping toward the ocean. Althouth the area is in the Yangsan fault zone no ground evidence of fault can be seen despite the RESTEC sattlite image gives excelent traces of linearments in the area.

• Geosciences Journal
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• v.22 no.6
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• pp.903-919
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• 2018

This paper focuses on the depositional processes and environmental changes during initial marine flooding recorded in the lower Cambrian succession of the North China Platform in Shandong Province, China. In order to understand imbalance of accommodation and sediment supply in the initial stage of basin-fill, a detailed analysis of sedimentary facies was made for the lowermost siliciclastic deposits of the Liguan Formation. It reveals ten siliciclastic lithofacies in three large-scale outcrops (Jinhe, Anqianzhuang, and Zhangjiapo sections). These facies are grouped into four facies associations, representing siliciclastic foreshoreshoreface (S1), siliciclastic offshore (S2), distributary mouth bars (S3), and coastal plain (S4). The siliciclastic components occur in a linear belt, emanating from a major drainage system in the northeastern part of the platform. Deposition of siliciclastic sediments was largely controlled by regional topography of the unconformable surface and shoreline configuration as well as strong effect of waves and currents. With ensued rise in sea level and decrease in siliciclastic sediment supply, carbonate sediments prevailed, filling the accommodation created by epeirogenic subsidence and sediment loading.

• Journal of the Korean association of regional geographers
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• v.14 no.1
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• pp.27-39
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• 2008

The propose of this research paper is to clarify the formative process of the lake-like swamps formed in channels of Nakdong-gang river and its tributary, Gumho-gang river. In order to understand the formative process of lake-like swamps, I compared topographical maps of three years(1918, 1962, 2005), analyzed the outline change of swamps, and draw their cross-sectional view and analyzed the horizontal distribution of particle size. Results of analysis are as follow. First, Saegang swamp and Geumgang swamps are residual swamps which are formed in abandoned distributary channels of braided reach. In braided reach, tributaries wind freely to create a new channel or to eliminate a old channel. Second, the Ssiksil swamp and Nat swamp are yazoo-type swamps. Their stream channels run parallel to the natural levees, as it blocks the waterway of a effluent tributary flowing from backward mountains to main stream. Third, the Secheon, Hochon and Jinchon swamps are backswamp behind natural levee. As main stream overflows, natural levee and back swamp are formed. Later flowing water of next bigger flood enter through natural levee into backswamp, create a channel following backswamp.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.970-975
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• 2005

측면웨어(side weir)는 본류의 수위가 한계수위 이상으로 상승할 경우 본류로부터 저류지나 분수로(distributary channel)로 흐름을 전환하기 위하여 사용하는 수공구조물이다. 최근 들어 치수와 관련된 계획에서 본류의 홍수량 중 일부를 저류지나 홍수 우회수로로 전환시키는 시설에 대한 관심이 높아지고 있다. 측면웨어가 하천에 설치되는 경우, 측면웨어 부근 표층부의 흐름은 측면웨어의 영향을 크게 받으며, 수의바닥이나 측면웨어에서 떨어진 지점의 흐름은 측면웨어의 영향을 작게 받는 등 측면웨어 주변부는 3차원적인 흐름특성을 보인다. 또한 측면웨어를 월류하는 흐름이 일반 웨어와 같이 웨어 마루부에 대하여 직각방향으로 흐르지 않고 본류의 유속에 따라 비스듬하게 흐르게 된다. 이러한 흐름특성으로 인해 측면웨어를 통과하는 유량은 본류의 하폭, 본류의 흐름특성, 측면웨어의 길이 및 설치위치 등에 따라 각기 다르게 산정되는 것으로 알려져 있다. 본 연구에서는 기존 측면웨에에 관한 연구를 정리하고 상용 프로그램인 FLOW-3D를 이용하여 측면웨어가 설치된 경우의 흐름을 해석하였다. 해석결과는 기존 실험연구에 바탕을 둔 이론식과 비교하였다. 계산격자는 구조물 부근의 흐름이 급변하는 곳은 격자크기를 작게, 흐름의 변화가 완만한 곳은 격자크기를 크게 하였다. 경계조건으로 상류는 유량, 하류는 수위경계를 입력하였다. 본 수치모의결과와 이론식을 이용하여 산정한 월류량을 비교한 결과 약 $10-30\% 내외의 오차가 발생하는 것으로 나타났다. 본류의 흐름은 웨어의 길이가 짧을수록 상$\cdot$하류단의 수위차가 작아지며 유속의 경우 웨어길이가 길고, 높이가 낮을수록 빨라진다. 측면웨어 주변부 흐름의 경우, 웨어의 길이가 짧을수록 방류강도가 강하고 횡방향의 수면변위가 급하게 형성되고 있음을 알 수 있다 또한, 웨어의 길이가 상대적으로 길어질 경우에는 3차원적 흐름특성에 의하여 유속의 분포가 다양하여 이론식과 결과의 오차가 점점 더 커짐을 알 수 있다. 본 연구는 사각형수로에 측면웨어가 설치된 경우, 월류량과 수리학적 거동을 해석할 때 수치모형실험이 수리모형실험과 더불어 유용한 해석도구로 이용될 수 있음을 보인 깃으로 이후 관련 구조물의 설계와 해석 시 참고자료로 이용 가능할 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.306-306
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• 2020

횡월류위어(side weir)는 하천의 수위가 한계수위 이상으로 상승할 경우 본류로부터 저류지나 분수로(distributary channel)로 흐름을 전환하기 위하여 사용하는 수공구조물로 강변저류지나 off-line저류지의 유입부에 흐름방향과 평행하게 설치되어 유량관리 및 전환, 홍수통제, 에너지 소산, 수위조절, 일정 유량의 취수 및 분배, 초과 홍수량의 전환 등의 목적으로 이용되는 구조물이다. 횡월류 위어의 월류 흐름은 일반위어와 같이 위어마루부 직각방향으로 흐르지 않고 본류 흐름특성에 따라 비스듬하게 유입된다. 이러한 흐름특성으로 횡월류위어 월류량은 본류의 하폭, 흐름특성, 위어길이 및 설치위치 등에 따라 각기 다르게 산정된다. 현재 국내에서 진행된 횡월류위어 흐름특성에 관련된 연구는 대부분 직선수로에 집중되어 있으며 사행하천의 흐름특성에 따른 연구는 부족한 실정이다. 금회 연구에서는 3차원 상용프로그램인 FLOW-3D를 이용하여 사행하천구간 유입부 설치위치 특성에 따른 횡월류 위어 유입흐름 특성을 분석하였다. 사행하천 구간 횡월류위어 설치위치에 따른 3차원 흐름해석을 위해 AUTO CAD 프로그램을 이용하여 수로길이 30m, 수로폭 2m의 구형 사행수로를 구성하였고, 횡월류위어 유입부 위치를 20°~120°로 변화시키며 수치모형실험을 수행하였다. 해석결과 수로흐름은 유입부 설치각이 작을수록 상·하류 수위차가 작아지며 유속이 감소하며 설치위치각이 클수록 수로내 평균유속은 증가하는 것으로 확인되었다. 유입부 설치각이 작을수록 방류량이 증가하여 수로내 흐름분리현상 증가하였고 이로인한 지체현상이 발생하는 것으로 확인되었다. 본 연구로 사행하천구간에 횡월류위어가 설치된 경우, 월류량과 수리학적 흐름특성을 해석할 때 3차원 수치모형실험이 유용한 해석도구로 이용될 수 있음이 확인되었다. 이후 수치모형실험이 수공구조물 설계 및 해석 시 참고자료로 이용 가능할 것으로 사료된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.250-250
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• 2021

횡월류위어(side weir)는 하천의 수위가 한계수위 이상으로 상승할 경우 본류로부터 저류지나 분수로(distributary channel)로 흐름을 전환하기 위하여 사용하는 수공구조물로 강변저류지나 off-line저류지의 유입부에 흐름방향과 평행하게 설치되어 유량관리 및 전환, 홍수통제, 에너지 소산, 수위조절, 일정 유량의 취수 및 분배, 초과 홍수량의 전환 등의 목적으로 이용되는 구조물이다. 횡월류 위어의 월류 흐름은 일반위어와 같이 위어마루부 직각방향으로 흐르지 않고 본류 흐름특성에 따라 비스듬하게 유입된다. 이러한 흐름특성으로 횡월류위어 월류량은 본류의 하폭, 흐름특성, 위어길이 및 설치위치 등에 따라 각기 다르게 산정된다. 현재 국내에서 진행된 횡월류위어 흐름특성에 관련된 연구는 대부분 직선수로에 집중되어 있으며 사행하천의 흐름특성에 따른 연구는 부족한 실정이다. 금회 연구에서는 3차원 상용프로그램인 FLOW-3D를 이용하여 사행하천구간 유입부 설치위치 특성에 따른 횡월류 위어 유입흐름 특성을 분석하였다. 사행하천 구간 횡월류위어 설치위치에 따른 3차원 흐름해석을 위해 AUTO CAD 프로그램을 이용하여 수로길이 30m, 수로폭 2m의 구형 사행수로를 구성하였고, 횡월류위어 유입부 위치를 20°~120°로 변화시키며 수치모형실험을 수행하였다. 해석결과 수로흐름은 유입부 설치각이 작을수록 상·하류 수위차가 작아지며 유속이 감소하며 설치위치각이 클수록 수로내 평균유속은 증가하는 것으로 확인되었다. 유입부 설치각이 작을수록 방류량이 증가하여 수로내 흐름분리현상 증가하였고 이로인한 지체현상이 발생하는 것으로 확인되었다. 본 연구로 사행하천구간에 횡월류위어가 설치된 경우, 월류량과 수리학적 흐름특성을 해석할 때 3차원 수치모형실험이 유용한 해석도구로 이용될 수 있음이 확인되었다. 이후 수치모형실험이 수공구조물 설계 및 해석 시 참고자료로 이용가능할 것으로 사료된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.237-237
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• 2015

The district of Marlborough has had more than its share of river management projects over the past 150 years, each one uniquely affecting the geomorphology and flood hazard of the Wairau Plains. A major early project was to block the Opawa distributary channel at Conders Bend. The Opawa distributary channel took a third and more of Wairau River floodwaters and was a major increasing threat to Blenheim. The blocking of the Opawa required the Wairau and Lower Wairau rivers to carry greater flood flows more often. Consequently the Lower Wairau River was breaking out of its stopbanks approximately every seven years. The idea of diverting flood waters at Tuamarina by providing a direct diversion to the sea through the beach ridges was conceptualised back around the 1920s however, limits on resources and machinery meant the mission of excavating this diversion didn't become feasible until the 1960s. In 1964 a 10 m wide pilot channel was cut from the sea to Tuamarina with an initial capacity of $700m^3/s$. It was expected that floods would eventually scour this 'Wairau Diversion' to its design channel width of 150 m. This did take many more years than initially thought but after approximately 50 years with a little mechanical assistance the Wairau Diversion reached an adequate capacity. Using the power of the river to erode the channel out to its design width and depth was a brilliant idea that saved many thousands of dollars in construction costs and it is somewhat ironic that it is that very same concept that is now being used to deal with the aggradation problem that the Wairau Diversion has caused. The introduction of the Wairau Diversion did provide some flood relief to the lower reaches of the river but unfortunately as the Diversion channel was eroding and enlarging the Lower Wairau River was aggrading and reducing in capacity due to its inability to pass its sediment load with reduced flood flows. It is estimated that approximately $2,000,000m^3$ of sediment was deposited on the bed of the Lower Wairau River in the time between the Diversion's introduction in 1964 and 2010, raising the Lower Wairau's bed upwards of 1.5m in some locations. A numerical morphological model (MIKE-11 ST) was used to assess a number of options which led to the decision and resource consent to construct an erodible (fuse plug) bank at the head of the Wairau Diversion to divert more frequent scouring-flows ($+400m^3/s$)down the Lower Wairau River. Full control gates were ruled out on the grounds of expense. The initial construction of the erodible bank followed in late 2009 with the bank's level at the fuse location set to overtop and begin washing out at a combined Wairau flow of $1,400m^3/s$ which avoids berm flooding in the Lower Wairau. In the three years since the erodible bank was first constructed the Wairau River has sustained 14 events with recorded flows at Tuamarina above $1,000m^3/s$ and three of events in excess of $2,500m^3/s$. These freshes and floods have resulted in washout and rebuild of the erodible bank eight times with a combined rebuild expenditure of $80,000. Marlborough District Council's Rivers & Drainage Department maintains a regular monitoring program for the bed of the Lower Wairau River, which consists of recurrently surveying a series of standard cross sections and estimating the mean bed level (MBL) at each section as well as an overall MBL change over time. A survey was carried out just prior to the installation of the erodible bank and another survey was carried out earlier this year. The results from this latest survey show for the first time since construction of the Wairau Diversion the Lower Wairau River is enlarging. It is estimated that the entire bed of the Lower Wairau has eroded down by an overall average of 60 mm since the introduction of the erodible bank which equates to a total volume of $260,000m^3$. At a cost of $$0.30/m^3$ this represents excellent value compared to mechanical dredging which would likely be in excess of $$10/m^3$. This confirms that the idea of using the river to enlarge the channel is again working for the Wairau River system and that in time nature's "excavator" will provide a channel capacity that will continue to meet design requirements.

• The Korean Journal of Petroleum Geology
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• v.11 no.1 s.12
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• pp.18-26
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• 2005

An occurrence of inclined heterolithic stratification (IHS) is described from a tidal point bar in a 40-m-deep distributary of the macrotidai, Han River delta, Korea. The channel bank demonstrates a convex-upward profile with intermittent presence or wave-formed scarps and terraces near the low-water level. The vertical succession of IHS is approximately 25 m thick and dips into the channel with angles reaching up to $14^{\circ}C$. The IHS overlies 15 m of trough cross-bedded sand deposited in the channel bottom. Even though the channel as a whole is ebb dominated, the preserved cross bedding is predominantly flood directed because the mutually evasive nature of the ebb and flood currents causes the point bar surface to be flood dominated. The IHS itself consists of inter-stratified fine sand, sandy silt, and silt with an fining-upward textural trend. Seasonal discharge variations of the Han River are not obvious in the deposits, because tile large size, distal location, and energetic tidal environment of the studied channel reduces the impart of river-stage fluctuations.