• 물과 미래
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• 제44권2호
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• pp.15-20
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• 2011

• 한국농공학회지
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• 제39권1호
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• pp.48-53
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• 1997

The sand bar has developed at the junction of the Kum-ho River and Shin-ryoung River. The sediment transported from the Kumho River basin has decreased since the Youngchon Dam has been functioning. Sand bar and the vicinity of the bottleneck at the upstrem of Kumho River and Osu Island which is consisted of sand bar have inundated frequently. This study was carried out through the hydraulic model test to calibrate the hydraulic effect from removal of sand bar in the river and straightening the river course by land reclamation. The water level of river at the vicinity of bottleneck can be lowered as much as 0.40~0.7m when the sand bar is removed. When river is straightened the river course by land reclamation the water level can be lowered as half of removal of sand bar.

• 한국수자원학회논문집
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• 제54권3호
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• pp.203-215
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• 2021

본 연구에서는 유역내 댐 건설과 하천내 식생성장으로 육역화 현상이 진행되는 내성천 환경 변화의 원인을 파악하기 위해 내성천 유역에 위치한 3개 관측소를 대상으로 2010년부터 2019년까지 관측된 수문자료와 항공사진 및 지형자료를 수집하여 수문특성에 따른 수위-유량관계 변화 및 횡단면의 침식·퇴적 변화율을 분석하였다. 또한 상류 지류인 월호교 관측소에서 인위적인 유량 조절 유무에 따른 영향을 비교하였다. 분석결과, 내청천에서는 2013년부터 2015년까지 지속적인 가뭄에 의해 홍수터에서는 식생활착 및 식생사주 면적 증가로 육역화가 진행되었고, 저수위에서는 흐름부 축소, 유속 및 하상소류력 증가로 지속적인 하상침식이 발생한 것으로 판단되었다.

• 한국환경과학회지
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• 제21권9호
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• pp.1131-1138
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• 2012

The aims of this study were to investigate and confirm the occurrence and distribution patterns of iodinated X-ray contrast media (iopromide) in Nakdong river basin (mainstream and its tributaries). Iopromide was detected in 16 sampling sites. The concentration levels of iopromide on February 2011 and on October 2011 in surface water samples ranged from not detected (ND) to 1481.1 ng/L and ND to 1168.2 ng/L, respectively. The highest concentration level of iopromide in the mainstream and tributaries in Nakdong river were Goryeong and Jincheon-cheon, respectively. The sewage treatment plants (STPs) along the river affect the iopromide levels in river and the iopromide levels decreased with downstream because of dilution effects.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권3호
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• pp.74-82
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• 2015

A method to filter out the effect of river stage fluctuations on groundwater level was designed using an artificial neural network-based time series model of groundwater level prediction. The designed method was applied to daily groundwater level data near the Gangjeong-Koryeong Barrage in the Nakdong river. Direct prediction time series models were successfully developed for both cases of before and after the barrage construction using past measurement data of rainfall, river stage, and groundwater level as inputs. The correlation coefficient values between observed and predicted data were over 0.97. Using the time series models the effect of river stage on groundwater level data was filtered out by setting a constant value for river stage inputs. The filtered data were applied to the hybrid water table fluctuation method in order to estimate the groundwater recharge. The calculated ratios of groundwater recharge to precipitation before and after the barrage construction were 11.0% and 4.3%, respectively. It is expected that the proposed method can be a useful tool for groundwater level prediction and recharge estimation in the riverside area.

• 한국환경과학회지
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• 제21권8호
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• pp.965-975
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• 2012

Loading of NPS pollutant was valued through simulation by using BASINS/HSPF model which can simulate runoff volume in rainfall by time. For the verification of the model, it was analyzed the scatter diagram of the simulation value and measure value of water quality and runoff volume in Dongcheon estuary. Using the built model, a study on the time-variant characteristics of runoff and water quality was simulated by being classified into four cases. The result showed the simulation value was nearly same as that of the measured runoff. In the result of fit level test for measured value and simulated value, correlation of runoff volume was computed high by average 0.86 and in the water quality items, fit level of simulation and measurements was high by BOD 0.82, T-N 0.85 and T-P 0.79.

• 한국환경과학회지
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• 제28권12호
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• pp.1071-1083
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• 2019

In this study, water quality levels were classified and water quality indices were calculated and analysed by using the water quality components of living environmental standards monitored 10 years (2008 ~ 2017) at four stations in the West Nakdong River. As a result of analyzing the monthly variation of the water quality components of the living environmental standards, the water quality in the West Nakdong River was worse downstream than upstream, and pollution at the WNR3 located in the downstream of the Jomangang was the most serious. As a result of classification of water quality levels, BOD and COD levels were the lowest, so water quality pollution in the West Nakdong River was found to be highly influenced by organic matters. The water quality index was the lowest in July and August at four stations, so water quality is showing the worst in summer. As a result of analyzing the correlation between the water quality components and the water quality index, the correlation between the TOC and the water quality index was high in the four stations, and the water quality index in the West Nakdong River was dominated by organic matters and nutrients.

• 한국환경과학회지
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• 제26권10호
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• pp.1135-1146
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• 2017

At riverbank filtration sites, groundwater levels of alluvial aquifers near rivers are sensitive to variation in river discharge and pumping quantities. In this study, the groundwater level fluctuation, pumping quantity, and streamflow rate at the site of a riverbank filtration plant, which produces drinking water, in the lower Nakdong River basin, South Korea were interrelated. The relationship between drawdown ratio and river discharge was very strong with a correlation coefficient of 0.96, showing a greater drawdown ratio in the wet season than in the dry season. Autocorrelation and cross-correlation were carried out to characterize groundwater level fluctuation. Autoregressive model analysis of groundwater water level fluctuation led to efficient estimation and prediction of pumping for riverbank filtration in relation to river discharge rates, using simple inputs of river discharge and pumping data, without the need for numerical models that require data regarding several aquifer properties and hydrologic parameters.

• Journal of Forest and Environmental Science
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• 제30권1호
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• pp.76-84
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• 2014

This study was performed to monitor the effects of water level change on changes of landscape, vegetation community, and species diversity of riparian forest. Hantan river dam, study area, has been constructed in the area of Chansoo-myeon, Pocheon-si and Yeoncheon-eup, Yeoncheon-gun, Gyeonggi-do, which is a dam for flood control only in flooding season. Landscape changes were notable after the construction of coffer dam, and the changes were caused by water level increase in areas of riparian forests which consisted of mainly withered willow as a dominant species in the flooding season. It changed vegetation communities of riparian forest from Phragmites japonica and Salix koreensis to Phragmites japonica. Species diversity index was lowest in 2010 when the coffer dam was constructed and showed an increasing trend later. Thus, this study is well in agreement with a previous report that plants of the genus Salix wither by muddy water during flooding and also suggests, controlling water level of river and prediction of water level change's effects should be considered when any facilities are planned.

• 한국물환경학회지
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• 제30권6호
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• pp.612-621
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• 2014

Physicochemical factors and the phytoplankton communities in the downstream area of Namhan-River were investigated from June 2012 to November 2013. We also assessed water quality using biological water quality indices. Total nitrogen was 2.4 mg/L, total phosphorus was 0.04 mg/L, and biological oxygen demand was 1.1 mg/L. This resulted in a level 2 (Ib, good) water quality rating. A total of 259 phytoplankton taxa were classified, consisting of 26 families, two subfamilies, 64 genera, 222 species, 32 varieties, and five formas. Bacillariophyceae dominated during a1l seasons and at all sites. The dominant species were Aulacoseira granulata, Cyclotella meneghiniana, C. stelligera, Melosira varians, Cocconeis placentula var. lineata, Nitzschia palea, N. amphibia, Cymbella minuta, and Achnanthes convergens. The diatom assemblage index for organic pollution values was level A-D, and TDI was level B-D. P-IBI at most sites was at the M (moderate) level, but TSI was at the E (eutrophic) level. Most indices dropped from upstream to downstream.