• 한국물환경학회지
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• 제31권6호
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• pp.723-731
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• 2015

We investigated the spatial and temporal patterns of water quality in the Gangjung-Goryoung weir that is located in the middle area of the Nakdong river, Korea. The monitoring results indicated that there are discernible vertical differences in water quality during the pre- and post-monsoon periods (May to September). During this period, it was observed that the weak thermal stratification formed at the maximum level, and pH, Chl-a, and DO concentrations in the surface layer were higher than those in the bottom layer. This vertical difference was especially noticeable for DO concentrations: there were DO depletions at the bottom layer in late June to early August. During the summer monsoon period with heavy rainfall, there was a decline in vertical differences in water quality. From this study, it was suggested that continuous monitoring of vertical profiles could become a useful tool for identifying the spatial and temporal distributions of water quality and for developing the best management policy for water quality in the Nakdong river.

• 한국물환경학회지
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• 제36권5호
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• pp.445-452
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• 2020

Tributary is a part of life space for people and a very important place that accommodates rest recreation and other daily activities. absolutely insufficient basic data about water quality and flow rate are available for basin management. Efficient water and basin management systems, which are also supported by local residents can be established by securing such basic data of major tributaries in the Nakdong river system. In this study, the fluctuation characteristics of upstream and downstream water pollution levels were compared using the measurement results of the water environment measurement network and the tributary monitoring project for the gyeseong-stream and Hwapo-stream in the Nakdong-miryang watershed. In 2017, when water pollution is the highest, it was confirmed that the annual average rainfall was the lowest. Although the upstream and downstream water quality tendencies of the Gyeseong-stream are similar, the water quality concentrations of the Gyeseong-stream are relatively different. But although the Hwapo stream has various causes of pollution, there was not much difference in the level of pollution between the upper and lower streams. In addition, both rivers need the ability to purify rivers by securing sufficient water for river maintenance, and if the correlation between water quality items can be inferred through continuous monitoring of tributaries where the aspect of water quality change is unclear, water quality management Determined to be efficient operation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권10호
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• pp.3275-3298
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• 2022

Cloud-based architectures for precision agriculture are domain-specific controlled and require remote access to process and analyze the collected data over third-party cloud computing platforms. Due to the dynamic changes in agricultural parameters and restrictions in terms of accessing cloud platforms, developing a locally controlled and real-time configured architecture is crucial for efficient water irrigation and farmers management in agricultural fields. Thus, we present a new implementation of an independent sensor-enabled architecture using variety of wireless-based sensors to capture soil moisture level, amount of supplied water, and compute the reference evapotranspiration (ETo). Both parameters of soil moisture content and ETo values was then used to manage the amount of irrigated water in a small-scale agriculture field for 356 days. We collected around 34,200 experimental data samples to evaluate the performance of the architecture under different agriculture parameters and conditions, which have significant influence on realizing real-time monitoring of agricultural fields. In a proof of concept, we provide empirical results that show that our architecture performs favorably against the cloud-based architecture, as evaluated on collected experimental data through different statistical performance models. Experimental results demonstrate that the architecture has potential practical application in a many of farming activities, including water irrigation management and agricultural condition control.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권6호
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• pp.22-35
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• 2016

Global climate change could have an impact on hydrological process of a watershed and result in problems with future water supply by influencing the recharge process into the aquifer. This study aims to assess the change of groundwater recharge rate by climate change and to predict the sustainability of groundwater resource in Pyoseon watershed, Jeju Island. For the prediction, the groundwater recharge rate of the study area was estimated based on two future climate scenarios (RCP 4.5, RCP 8.5) by using the Soil Water Balance (SWB) computer code. The calculated groundwater recharge rate was used for groundwater flow simulation and the change of groundwater level according to the climate change was predicted using a numerical simulation program (FEFLOW 6.1). The average recharge rate from 2020 to 2100 was predicted to decrease by 10~12% compared to the current situation (1990~2015) while the evapotranspiration and the direct runoff rate would increase at both climate scenarios. The decrease in groundwater recharge rate due to the climate change results in the decline of groundwater level. In some monitoring wells, the predicted mean groundwater level at the year of the lowest water level was estimated to be lower by 60~70 m than the current situation. The model also predicted that temporal fluctuation of groundwater recharge, runoff and evapotranspiration would become more severe as a result of climate change, making the sustainable management of water resource more challenging in the future. Our study results demonstrate that the future availability of water resources highly depends on climate change. Thus, intensive studies on climate changes and water resources should be performed based on the sufficient data, advanced climate change scenarios, and improved modeling methodology.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 추계학술대회
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• pp.389-391
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• 2022

지하에 매설된 상·하수의 노후화를 관리하기 위한 환경부와 국내 지자체의 노력이 이어지고 있다. 한국환경산업기술원의 상·하수 혁신 기술 개발사업 지원으로 노후화에 따른 사고예측 및 교환시기 관리, 신규 매설 배관에 스마트 기능을 적용하는 사업을 진행하고 있다. 이러한 연구의 하나로 본 논문에서는 전체 연구의 핵심 특징 중 하나인 디지털 트윈 기반 스마트 파이프 상태 모니터링을 위한 대시보드 개념 모델의 설계를 제안하였다. 원격 제어와 모니터링이 주요 기능 중 하나이기 때문에 분산 송수신 에이전트를 배치해 모니터링 상황을 실시간으로 시각화하고 직관적인 UI를 배치해 사용자 친화력을 높혔다. 이 제안된 특수 디지털 트윈 기반 스마트 파이프 상태 모니터링의 설계를 검증하기 위해 개념 모델 수준을 구성하고 에이전트 효과를 측정하여 우수성을 검증하였다.

• 한국농공학회논문집
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• 제50권2호
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• pp.65-71
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• 2008

A monsoon season monitoring data from June to September, 2005 of a small forested watershed located at the upstream of the North Han River system in Korea was conducted to analyze the flow variations, the NPS pollutant concentrations, and the pollution load characteristics with respect to sampling frequencies. During the 4-month period, 1,423 mm or 79.2% of annual rainfall(1,797 mm) were occurred and more than 77%, 54% and 68% of annual T-N, $NO_3$-N and T-P loads discharged. Flow rate was continuously measured with automatic velocity and water level meters and 58 water quality samples were taken and analyzed. It was analyzed that the flow volume by random measurement varied very widely and ranged from 79% to 218% of that of continuous measurement. It was recommended that flow measurement of small forested watersheds should be continuously measured with automated flow meters to precisely measure flow rates. Flow-weighted mean concentrations of T-N, $NO_3$-N and T-P during the period were 2.114 mg/L, 0.836 mg/L, and 0.136 mg/L, respectively. T-N, $NO_3$-N and T-P loads were sensitive to the number of samples. And it was analyzed that in order to measure the pollution load within the error of 10% to the true load, the rate of sampling frequency should be higher than 89.7% of the sample numbers that were required to compute the true pollution load. If it is compared to selected foreign research results, about 10 water samples for each rainfall event were needed to compute the pollution load within 10% error. It is unlikely in Korea and recommended that thorough NPS pollution monitoring studies are required to develop the standard monitoring procedures for reliable NPS pollution quantification.

• 대한원격탐사학회지
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• 제36권5_4호
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• pp.1245-1254
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• 2020

본 연구에서는 CCTV 영상을 이용한 기존 수위감지 알고리즘의 한계점을 보완하기 위하여 Region growing 기법을 적용하였다. 먼저 세 가지 기법(수평 투영 프로파일, Texture 분석, Optical flow)을 적용해 물 영역을 추정하고, 기법별 결과를 종합 분석하여 최초 수위를 설정하였다. 이후 최초 수위를 기준으로 Region growing을 통해 수위 변화를 지속적으로 감지하도록 하였다. 그 결과, 주변 환경요인에 영향 없이 수위를 올바르게 감지하였으며, 영상분석 결과에 대한 전반적인 오차 평균은 5% 미만인 것을 확인할 수 있었다. 또한, 본 알고리즘이 하천이 아닌 도심지 내 침수 도로 영상에서도 물 영역이 감지되는 것을 확인할 수 있었다. 이러한 결과는 전국에 설치된 수많은 CCTV 영상을 통해 자동적으로 수위를 감지함으로써 제한된 인력으로 상시 모니터링이 어려웠던 점을 보완할 수 있으며, 집중호우, 태풍 등으로 인해 발생되는 사고발생 위험성을 사전에 인지하여 예방할 수 있는 기반을 마련하는데 기여할 수 있을 것으로 생각된다.

• 생태와환경
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• 제56권4호
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• pp.348-362
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• 2023

본 연구는 대하천에 건설된 16개 보의 어도 모니터링 결과를 분석하여, 어도의 운영 및 관리에 도움이 되는 자료를 제공하고자 하였다. 보별 어도 이용률은 평균 64.9%로 확인되었으며, 본류와 어도 모니터링 결과의 우점종을 비교한 결과 총 9개(56.3%)의 보에서 차이를 보였다. 이를 통해 본류에 다수 서식하는 종이 어도를 다수 이용하는 것은 아닌 것으로 확인되었다. 어류의 하루 어도 이용 개체수는 평균 336개체로 확인되었다. 어도 이용 어종을 생태형으로 구분한 결과 92.3%가 일차담수어였으며, 회유성 어종은 5.6%로 높지 않다. 어도 이용 시기에 따른 분석에서 5월부터 10월까지 평균 이상의 어류가 어도를 이용하였으며, 그중 이용 개체수는 6월~8월이 가장 많았다. 5월~7월까지 어도 이용 어종의 80%가 산란시기에 포함되었으며, 이외 시기는 산란시기 포함 어종이 40% 이하로 나타났다. 산란시기와 어도 이용 시기가 크게 일치하는 어류는 밀어, 밀자개, 참몰개, 모래무지, 납지리, 돌고기 순서로 확인되었다. 강정고령보와 달성보의 어도 모니터링 결과를 보의 수위와 비교한 결과, 어도 이용 종수 및 개체수 모두 보의 상류 수위와 양의 상관성을 보였으며, 이를 통해 수위가 높을수록 어도 내 유입 유량이 증가하여 어도의 어류 이용(강정고령보 개체수, P<0.001; 달성보 종수, P<0.05)이 증가하는 것으로 확인되었다. 본 연구에서는 대하천에 건설된 16개 보의 어도 모니터링에 결과를 정리 및 분석하여, 어도의 효율, 어도 운영 및 모니터링 시기 제안, 어도 운영을 위한 수위 조절 등을 고찰하였다. 이는 대하천 어도의 어류 이용 현황에 대한 이해와 더불어, 향후 국내 어도의 설치, 운영, 모니터링 등 관리에 도움이 될 수 있을 것으로 판단된다.

• Bulletin of the Korean Chemical Society
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• 제28권3호
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• pp.373-378
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• 2007

A micro organism Agrobacterium tumifacient as an immobilized cell on a solid support was presented as a new biosorbent in a simple and sensitive spectrophotometry determination of Ni(II) in various samples using 4-hydroxy benzaldehyde-4-bromophenyl hydrazone as a color developing agent (λmax 497 nm) at pH 4.0 ± 0.2. Beer's law was obeyed over the range of 0.01-0.1 μg L-1. The molar absorptivity and Sandell's sensitivity were 1.285 × 105 L mol-1cm-1 and 0.007245 μg cm-2 respectively. Under these conditions, the preconcentration factor obtained was 82, and the detection limit achieved was 0.05 μg L-1. The detailed study of various interfering ions made the method more sensitive and selective. The recovery of Ni(II) from various samples range from 97.75 to 99.35%. The present method was successfully applied for the determination of Ni(II) in spiked, natural water and alloy samples. The proposed method was compared with reported methods in terms of Student's ‘t'-test and Variance ratio ‘f'-test which indicates that there is no significant difference between proposed and literature method at 95% confidence level.

• 한국환경보건학회지
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• 제40권1호
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• pp.47-54
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• 2014

Objectives: The purpose of this study is to evaluate the characteristics of leachate discharged from livestock burial sites in Gangwondo resulting from foot-and-mouth disease by monitoring the water quality at the survey tube-wells installed near livestock burial sites in order to investigate the effect of the leachate on the quality of nearby underground water and suggest a water pollution level in accordance with water quality evaluation criteria. Methods: To minimize the secondary environmental pollution damage caused by leachate at burial sites of livestock killed by foot-and-mouth disease, this study analyzed the leachate directly discharged from burial sites and installed survey tube-wells within 300 meters of livestock burial sites and investigated water quality as a means to ascertain the environmental effect of the leachate from the burial sites. In accordance with environmental management guidelines on livestock burial sites, this research investigated the water quality in the survey tube-wells in fifty five burial sites in Gangwondo. The elements investigated were $NH_3$-N, $Cl^-$, $NO_3$-N, conductivity, and E. coli. Water quality was monitored from 2011 to 2013. Results: The water quality from the drain pipe at the location of leachate from livestock burial sites showed BOD 37,209 mg/L, COD 8,829 mg/L, $NH_3$-N 3,633 mg/L, and $Cl^-$ 580 mg/L. According to the monitoring results of water quality ($Cl^-$, $NH_3$-N, conductivity) at the survey tube-wells, there was suspicion that 13 out of 55 burial sites discharged leachate, five sites discharged highly concentrated leachate (13%): one in Gangneung, one in Wonju, and three in Cheorwon. Conclusion: It was judged that out of thirteen observation wells which showed a possibility of discharged leachate, three survey tube-wells have established the discharge effect of leachate at burial sites up to recently. Therefore, it is judged that it is necessary to continue monitoring them and devise additional measures.