• 한국환경과학회지
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• 제4권3호
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• pp.187-196
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• 1995

Phosphorus and nitrogen loadings from the main tributaries into the Nakdong River were estimated by measuring phosphorus and nitrogen concentration in the main tributaries, Nakdong River(Kangjung), Kumho River, Heichun, Hwang River, Nam River, Milyang River, and Yangsanchun from May 1994 to October. Total Phosphorus concenuation of Kumho River was vary high, average 1.0 mgP/1. The other rivers were the range 0.05 ~0.15 mgP/1. Total nitrogen concentration of Kumho River was vary high, average 6.27 mgN/1. The other rivers were the range 1.5~3.0 mgN/l. The phosphorus loading from Kumho River, Nakdong River(Kangjung), Nam River, Milyang River, Hwang River, Yangsanchun, and Heichun were calculated to be 1, 108, 603, 198, 57, 34, 23, and 21 tP/yr, respectively. Therefore, the loading from Kumho River accounted for 45 "yo of total loading, 2, 042 tP/yr, The nitrogen loading from Nakdong River (Kangjung), Kumho River, Nam River, Milyang River, Hwang River, Heichun, and Yangsanchun were calculated to be 12, 636, 7, 411, 2, 611, 1, 523, 779, 608, and 391 tN/yr, respectively. Therefore, the loading from Nakdong River(Kangiung) and Kumho River accounted for 50 % and 30% of total loading, 25, 959 tN/yr, respectively.vely.

• 한국환경복원기술학회지
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• 제12권3호
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• pp.83-97
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• 2009

The objects of study is to propose criteria for physical river disturbance assessment and as case study to show the application results for river improvement. For this purpose, the river disturbance assessment method for past disturbance process and the present-day potential natural state of stream is proposed. To assess the disturbance of the Youngcheon River caused by river improvement, One ares of Nam River was selected for the reference reach and two areas of Youngcheon River were selected for the comparison reach. And these reaches were surveyed and analyzed according to applying criteria of the river disturbances assessment. The assessment indices were physical factors as like epifaunal (bottom), embededness, velocity/depth regime, sediment deposition, channel flow status, channel alteration, frequency of riffles, bank stability, vegetative protection and riparian zone etc. The results showed that physical river environment in Youngcheon River area was disturbed by artificial revetment and bed excavation, consequently this disturbance give rise to impact of ecosystem in river. Hereafter, the criteria for river disturbance assessment are needed to consider various river characters as bed materials and bed slop etc.

• 한국환경과학회지
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• 제26권12호
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• pp.1389-1397
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• 2017

In this study, we calculated the fixed-type Areal Reduction Factor (ARF) of the Hancheon River basin in Jeju Island, and compared the calculated ARF and the ARF of the four major river basins suggested by the Ministry of Land, Infrastructure and Transport. As a result, the maximum fluctuation ratios of ARF for the four major river basins calculated using area, frequency, and initial duration time were significant: 7.61% for the Hangang River basin; 12.69% for the Nakdonggang River basin; 8.09% for the Kumgang River basin; and 17.98% for the Yeongsangang River basin. In addition, the differences between the maximum and minimum value of ARF for the Hancheon River basin based on 48 hours was 2.13%, and it was smaller than the one for the four major river basins: 8.92% for the Hangang River basin; 11.41% for the Nakdonggang River basin; 8.87% for the Kumgang River basin; and 17.17% for the Yeongsangang River basin. The Yeongsangang River basin had the highest difference.

• 한국습지학회지
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• 제9권3호
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• pp.51-61
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• 2007

자연하천은 하천개수사업, 유역의 토지이용 변화, 댐 및 저수지 건설, 골재채취 등 여러 가지 요인에 의해 하상이 변동하게 된다. 이러한 하상변동은 하천정비 및 다양한 습지계획, 안정하도 유지관리를 위해 매우 중요한 사항이다. 본 연구에서는 골재채취로 인해 저하된 하상이 점차 안정화 되어가고 있는 금강 및 미호천 국가하천 구간을 대상으로 하천측량, 하상재료 채취 분석을 실시하고, 이를 토대로 하도 형성을 지배하는 하도특성량 분석과 수치모형에 의해 장래 하상변동을 예측하였다. 연구결과 하상경사 및 마찰속도 등 하도특성량을 통해 분석한 하상변동 잠재성 평가 결과와 수치모형을 이용한 하상변동 예측결과가 비슷한 경향을 나타냈으며, 금강 및 미호천은 장래 하도가 안정화될 것으로 분석되었다. 이와 같이 장래 하상의 세굴 또는 퇴적경향 등을 예측하고 그 특성을 반영하면, 치수적인 대책 수립과 수리적으로 안전한 구간에서의 식생호안 설치 등 치수적으로 안전하고 친환경적인 하천 및 습지계획이 가능할 것이다.

• 환경영향평가
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• 제16권3호
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• pp.187-194
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• 2007

It started road constructions around river in 1990s. These maintenances concentrate on city river. Because river lives no living things and men don't come near there. But in spite of these river environment go to rack, river maintenances still keep on using preexistence method since 1990s. Only a part of city river environment maintenances consider environmental ability of passive river, river maintenance of a purpose of flood control still don't consider in the concrete. Because propulsion device that consider environment ability of passive river and possible application techniques don't complete. In accordance, A natural river maintenance needs absolutly a series of river projects. Because a natural river maintenance prevents a damage of environment ability. This study is to assume the flood really happened and to carry out the flood damage simulation needed in overflow simulation about the inundated zone. Also, This study examine unstable part about the hydraulic characteristic as velocities, stream power, shear, hydraulic depth, flow area in basin. And this study applied the HEC-RAS(river analysis system) model to predict flood overflow in youngsan river basin. Project flood is used the return period 100 year and inputed data that was calculated in intensity figures of illumination.

• Water Engineering Research
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• 제6권3호
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• pp.113-122
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• 2005

Periphyton is known to be one of major primary producers for river ecosystem. While the growth of periphyton usually observed on the stone surface in gravel river, the large growth of periphyton is sometimes seen even in sand river with relatively small river discharge. In the present study, field observations and numerical simulations were performed to investigate the growth of periphyton in sand river. In the field observation, the growth of periphyton on fixed sand bed was measured weekly. The results of the field observations show that the large growth of periphyton occurs in sand river until the bed material sands have not moved. An integrated numerical simulation model is presented to describe the growth of periphyton at observed river reach, and a series of numerical simulations were performed to study the effect of river discharge on growth of periphyton in the sand river. The results of the numerical simulations show that the net primary production of periphyton decreases with the river discharge. These results suggest that the reduction of river discharge at ordinary water stage strongly affects the primary productivity of periphyton even in sand river.

• 한국환경과학회지
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• 제22권6호
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• pp.695-703
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• 2013

In this study, the effects of four major river project and Kumho River, second biggest branch of Nakdong River, were investigated to provide basic data for proper management of Nakdong River's water quality. Daily sampling processes at three different points, Munsanri (the upper side of Kangjung-Koryung weir), Kangchang (the outlet of the Kumho River) and Samunjin (the lower side of Kangjung-Koryung weir and junction of Kumho River and Nakdong River), were conducted from May 1st 2011 to Sep. 4th 2011. Water samples were analyzed for nine factors, DO, BOD, COD, T-N, T-P, pH, turbidity, SS, and coliform. As demonstrated by the results, concentrations of BOD, T-N, T-P and coliform at Nakdong River were affected by water quality of Kumho River while SS and turbidity were affected by constructions for Kangjung-Koryung weir. Further studies, for example, affects of wastewater treatment facilities, should be followed.

• 한국습지학회지
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• 제12권2호
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• pp.87-93
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• 2010

하천의 다양성을 반영할 수 있는 하천복원 계획수립 및 선정방법이 필요하다. 한편, 하천복원의 궁극적인 목적은 하천 본래의 자연성 회복에 있으며, 최근에는 친수적 증진을 포함하는 추세이다. 본 연구에서는 자연형 하천복원 대안선정에 하천자연도을 적용하였다. 또한 하천자연도는 국내실정에 맞도록 다기준 의사결정을 활용하여 개발된 하천자연도평가법을 사용하여 산정하였다. 대상하천의 하천자연도 평가항목은 하천의 특성을 고려하여 선택한 후, 복수의 대안을 구성하고 대안별 하천자연도를 산정하여 비교하면, 각 대안별 자연성 회복효과 및 성과를 측정하는 것이 용이하였다.

• 상하수도학회지
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• 제36권5호
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• pp.289-296
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• 2022

Mangyeong River and Dongjin River are highly dependent on external regions for domestic and agricultural water, and the agricultural water supply and use system of those rivers are very complicated. For smooth water supply, rivers are used as a supply system. Of the total river water use permits (as of 2019), agricultural water accounts for 97.5%, 80.4% in Mangyeong River and Dongjin River, respectively. The excessive intake of river water as agricultural purpose is causing the stream to dry out and to deteriorate the ecological health of the river. It is necessary to minimize the water use system that takes in and utilizes river water. In both rivers, the flow rate of agricultural drainage and the load of major water quality items that flowing into the main stream are similar to or higher than those of the major tributaries, indicating that management is necessary to improve the water quality of the river. It is necessary to understand the effect of agricultural drainage on river water quality by establishing a continuous monitoring system for the form of agricultural drainage.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2011년도 학술발표회
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• pp.185-185
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• 2011

Mapping of artificial levee lines, one of major tasks in river zone mapping, is critical to prevention of river flood, protection of environments and eco systems in river zones. Thus, mapping of artificial levee lines is essential for management and development of river zones. Coastal mapping including river zone mapping has been historically carried out using surveying technologies. Photogrammetry, one of the surveying technologies, is recently used technology for national river zone mapping in Korea. Airborne laser scanning has been used in most advanced countries for coastal mapping due to its ability to penetrate shallow water and its high vertical accuracy. Due to these advantages, use of LiDAR data in coastal mapping is efficient for monitoring and predicting significant topographic change in river zones. This paper introduces a method for construction of a 3D artificial levee line using a set of LiDAR points that uses normal vectors. Multiple steps are involved in this method. First, a 2.5-dimensional Delaunay triangle mesh is generated based on three nearest-neighbor points in the LiDAR data. Second, a median filtering is applied to minimize noise. Third, edge selection algorithms are applied to extract break edges from a Delaunay triangle mesh using two normal vectors. In this research, two methods for edge selection algorithms using hypothesis testing are used to extract break edges. Fourth, intersection edges which are extracted using both methods at the same range are selected as the intersection edge group. Fifth, among intersection edge group, some linear feature edges which are not suitable to compose a levee line are removed as much as possible considering vertical distance, slope and connectivity of an edge. Sixth, with all line segments which are suitable to constitute a levee line, one river levee line segment is connected to another river levee line segment with the end points of both river levee line segments located nearest horizontally and vertically to each other. After linkage of all the river levee line segments, the initial river levee line is generated. Since the initial river levee line consists of the LiDAR points, the pattern of the initial river levee line is being zigzag along the river levee. Thus, for the last step, a algorithm for smoothing the initial river levee line is applied to fit the initial river levee line into the reference line, and the final 3D river levee line is constructed. After the algorithm is completed, the proposed algorithm is applied to construct the 3D river levee line in Zng-San levee nearby Ham-Ahn Bo in Nak-Dong river. Statistical results show that the constructed river levee line generated using a proposed method has high accuracy in comparison to the ground truth. This paper shows that use of LiDAR data for construction of the 3D river levee line for river zone mapping is useful and efficient; and, as a result, it can be replaced with ground surveying method for construction of the 3D river levee line.