• 한국해양공학회지
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• 제21권2호
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• pp.22-34
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• 2007

We present basic data for developing new research topics and closely examine the existing data on the development and organization of the Nakdong River Estuary Delta by analyzing various studies of the area, including ocean engineering, coastal engineering, ocean environmental engineering, geomorphological, and geological studies. We first defined the general concepts related to the estuary and delta and reviewed the historical development of the Nakdong River Estuary Delta over the past 100 years. We then examined the origin and core elements of the estuary deposits that constitute the delta. In addition, we scrutinized the main factors affecting the development of the delta and analyzed existing research on delta development mechanisms by core researchers. The construction of an estuary barrage is one of the main factors effecting estuarine circulation and has altered the physical oceanic environment, area of deposition, atmospheric environment, and vegetation community of the delta. These factors affect the estuary circulation in turn, altering the delta. Along the Nakdong River, an unsteady-state sandy barrier appears at approximately three times the distance of the wavelength of incident offshore waves, and this terrain forms approximately 10-15 years after reclamation in the interdistributary upper stream and transforms the shoreline. It is necessary to develop a technique to predict terrain change that reproduces the erosion and accumulation of estuarine deposits. To determine the parameters and variables necessary to reproduce this system, continuous on-site monitoring is necessary. The existing research did not fully examine the terrain changes in Nakdong River Estuary or the periodic developmental characteristics. To understand the future process of estuary delta development, it is necessary to establish an integrated management system.

• 대한토목학회논문집
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• 제37권3호
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• pp.561-573
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• 2017

낙동강에서 다기능보의 건설과 하도의 준설로 인해 수심은 더욱 깊어졌으며 유속이 느려져 지체시간 또한 증가하였다. 이로 인해 수심이 깊은 일부구간에는 성층현상이 발생하였으며, 또한 녹조현상을 가중시키는 원인이 되었다. 본 연구에서는 저수지와 하구언에서 성층현상 재현성이 입증된 3차원 수리 수질 해석모형인 EFDC 모형을 낙동강에 적용하여 성층현상의 재현성을 평가하고자 하였다. 낙동강 수온 및 DO 성층화 현상을 재현하기 위해 낙동강 중 하류부에 EFDC 모형을 구축하고 성층화에 민감한 주요 매개변수에 대한 민감도 분석을 수행하였으며, 민감도 분석을 통해 최적의 매개변수를 선택하여 성층화를 재현하였다. 본 연구의 결과는 다양한 성층교란 시나리오 분석의 기초자료로 활용될 수 있을 것으로 판단된다.

• 한국물환경학회지
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• 제37권1호
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• pp.32-46
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• 2021

South Korea has been divided into quantities and water quality, and due to a revision of the Government Organization law in June 2018, the controversial water management system was integrated into the Ministry of Environment. The total Maximum Daily Loads System has been called the flower of water quality control, and since 2004, all three major river systems which have been introduced into the Han River system, despite its various difficult environments, and subsequently leading to all of the four major rivers undergoing obligatory implementation since 2013. Currently, the target TMDL (Han River Phase 1 and Other Water Systems Phase 3) for the 2020 stage has been implemented. The domestic TMDL established a basic plan for calculating the load which complies with the unit watershed's target water quality, as well as an implementation plan for annual load management, both which have been institutionalized in order to evaluate load compliance on a repeated annual basis. Local governments ask external organizations to conduct investigations every year in order to assess the transition, which thereby requires tens of millions of won every year. Therefore, an assessment and management model that can be easily operated at the TMDL personnel level is required. In this study, when the Han river Water System TMDL was implemented in earnest, we confirmed the the water quality improvement effect when TMDL was introduced to major inflow tributaries (TancheonA, JungnangA, AnyangA) under the Seoul City's jurisdiction through the use of the total amount control unit basin evaluation technique. By presenting customized management measures, we propose the guidelines that are necessary for determining more effective water environmental policies.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.246-246
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• 2015

Runoff at any given location along a stream can be expressed as a function of its upstream area. The runoff-drainage area relationship can be well expressed as power-law (Brush, 1961) with its exponent, ranging as high as unity (e.g., Stall and Fok, 1968) and as low as 0.5 in natural rivers. Here, we study the runoff-drainage area relationships for Han River and Nakdong River, Korea. We find that the relationships follow power-law and their exponents are highly related with occurrence frequency of flow. To support this, we analyze flow frequency with historical data measured over decades. Findings in this study can broaden our understanding on mechanisms behind the catchment response to runoff.

• 자원환경지질
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• 제27권6호
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• pp.593-599
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• 1994

Drainage patterns were investigated to interpret the unknown geologic structure and geomorphic history in South Korea. Dendritic and rectangular patterns are most prominent ones developed in the granitic and sedimentary terrain. Drainage density ranges from 0.47 in the Nakdong river basin to 0.31 in the South Han river basin. Fine drainge texture is appeared in the Nakdong basin characterized by sedimentary beds of Mesozoic age, and coarse one are in the South Han river basin where Precambrian metamorphic rocks are dominated. Geological structures interpreted by stream pattern analysis are reasonally good agreement with the result by lineaments analysis and geological mapping.

• 한국농공학회지
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• 제32권1호
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• pp.103-109
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• 1990

The application of the Log-Pearson Type m distribution recommended by Water Resources Council, U. S. A. for flood frequency analysis requires the estimation of the regionalized skew coefficient. In this study, regionalized skew coefficients are estimated using a weighted regression model which relates at-site skews based on logarithms of observed annual flood peak series to both basin characteristics and precipitation data in the Han river and the Nakdong river basin. The model is developed with weighted least squares method in which the weights are determined by separating residual variance into that due to model error and due to sampling error. As the result of analysis, regionalized skews are estimated as - 0.732 and - 0.575 in the Han river and the Nakdong river basin, respectively.

• 한국환경과학회지
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• 제32권12호
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• pp.943-953
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• 2023

This study analyzed the ecological characteristics of the wetland protection area at tthe Nakdong River through vegetation and biota surveys, which showed that brackish water meets fresh water, a unique ecological environment has been created, biodiversity is high, and diverse habitats are distributed. Eleven plant communities, including four woody communities and seven grass communities, are distributed along the coast, and a total of 514 species, including 11 endangered wildlife species, were identified in terms of species diversity. Among them, the species diversity of the Eulsuk-do area was found to be relatively higher than that of other Barreir Islands areas. The presence of a population of Sterna albifrons on Sinja-do and a population of Eremias argus on Jinwo-do, an area outside the boundaries of the wetland protection area, confirmed the conservation value of the wetlands and the need to expand the boundaries of the wetland protection area. It is judged that this information can be used as basic information for a systematic conservation and management plan for the wetland protection area at the Nakdong River Estuary and as basic data to support the establishment of a policy.

• 한국환경생태학회:학술대회논문집
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• 한국환경생태학회 2007년도 정기총회 및 학술논문발표회
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• pp.219-222
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• 2007

• 한국환경과학회지
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• 제15권4호
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• pp.349-357
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• 2006

The purpose of this study is to evaluate the water pollution degree in the Mid-Nakdong River watershed regarding to landcover types using GIS method. As a result of landcover classification, rate of urban appeared highly on Daegu Metropolitan city. Also, rate of agriculture showed highly in the riparian zones of the Nakdong and Guemho River and rate of forest appeared highly in the borders of the study area. To identify the groups of watershed with similar landcover patterns using the Cluster Analysis. According to the cluster analysis, the fifty sub-watersheds were grouped in three clusters, 'Urban watershed', 'Agriculture watershed', 'Forest watershed'. The proportion of urban area in each cluster had a positive correlation with water pollution degree. Otherwise, the proportion of agriculture in the Agriculture watershed had a high positive correlation with water pollution degree. Therefore, it is necessary to estimate environmental capacity of water duality considering ecological and environmental characteristics of watershed ecosystem and expand water duality monitoring systems to small stream.

• Journal of Species Research
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• 제10권2호
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• pp.134-141
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• 2021

During a survey of indigenous prokaryotic species diversity of the upstream Nakdong River, South Korea, 12 bacterial strains were isolated for further analysis. These bacterial strains were identified showing at least 98.7% 16S rRNA gene sequence similarity with known bacterial species that were previously unreported in South Korea. The 12 bacterial strains were phylogenetically diverse and assigned to four classes, eight orders, nine families, and ten different genera. The isolates were identified as Leucobacter holotrichiae (99.1%), Leucobacter tardus (99.9%), Rhodococcus rhodochrous (99.9%), Tessaracoccus oleiagri (100%), and Paeniglutamicibacter cryotolerans (99.3%), of the class Actinobacteria; Bacillus coagulans (99.7%) and Bacillus wudalianchiensis (99.1%) of the class Bacilli; Ochrobactrum pseudogrignonense (99.2%) and Paracoccus thiocyanatus (100%) of the class Alphaproteobacteria; and Ideonella azotifigens (99.0%), Polaromonas glacialis(99.3%), and Herbaspirillum seropedicae (99.5%) of the class Betaproteobacteria. The cellular and colonial morphology, biochemical properties, and phylogenetic position of these isolates were examined, and species descriptions are provided.