• 한국지하수토양환경학회지:지하수토양환경
• /
• 제16권6호
• /
• pp.106-112
• /
• 2011

This study developed preliminary assessment methodology for priority listing of soil and groundwater contamination sources, considering source characteristics, local environments and risk receptors. Source characteristics were evaluated by scoring relative risk of contamination sources. Local environments were evaluated by scoring annual rainfall, hydraulic conductivity of aquifer, and annual groundwater use. Risk receptors were evaluated by scoring local population, direct distance to surface water, direct distance to drinking-water wells. Scores of each parameter were allocated by analysing distribution of parameter values obtained from government databases. Distributed scores of source characteristics local environments: risk receptors were 12 : 12 : 12. The preliminary assessment scored 0 to 36 for each soil and groundwater sources. Inventory of soil and groundwater sources consisted of 7 categories. This study applied the preliminary assessment methodology to Manan-Gu, Anyang City, Korea. The number of car repair and washing facility was the largest in the contamination source inventory. Petroleum storage facilities showed the highest assessment score. The preliminary assessment methodology also indicated that Anyang-Dong was the priority section among Anyang-Dong, Suksu-Dong, Bakdal-Dong. This study is the first trial for relative ranking soil and groundwater contamination sources by considering source and local characteristics. Therefore, further researches and revision of the preliminary assessment methodology need to be pursued for various applications.

• 한국물환경학회지
• /
• 제36권6호
• /
• pp.546-558
• /
• 2020

While industrialization has provided in abundance, the pollution it creates has caused untold damage to the environment, increasing the frequency and severity of natural disasters through changes in global climate patterns. The World Risk Forum's (WEF) World Risk Report presented the results of a survey of experts from around the world detailing the most influential risk factors over the next decade. Notably, the failure to respond to climate change ranked first and the global water crisis third. The extreme drought in the western Chungnam province was unexpected in 2016. At the time, the water level of Boryeong Dam was drastically decreased due to receiving less than half the average recorded rainfall in the region that year. The Boryeong Dam diversion pipeline has the capacity to solve the water shortage problem between these two regions by providing water from Geumgang to the western part of Chungnam, including Boryeong City. Current weather trends suggest drought is likely to continue in western Chungnam, which uses the Boryeong Dam as an intake source. This makes it necessary to operate Boryeong Dam diversion pipeline in an efficient and effective manner. SWAT is a watershed scale model developed to predict the impact of land management practices on water. The SWAT model was used in this study to evaluate the adequacy of the Boryeong Dam diversion pipeline operational plan by comparing it to present Boryeong Dam diversion pipeline operation. By investigating the number of days required to reach each reservoir stage, we determined that the number of days required to reach the boundary stage was less than that of the current operation. This determination accounts for the caveats that the Boryeong Dam waterway was not operated and only one pump will be operated from October to May of next year. As our results suggest, the most stable operation scenario is to operate two pumps at all times. This can be accomplished by operating two pumps from the caution stage to increase the number of pumps whenever the stage is raised. In addition to the stable operation of the Boryeong Dam pipeline, policy considerations are required with regard to imposing a water use charge on users of the Boryeong Dam region.

• 물과 미래
• /
• 제23권4호
• /
• pp.499-507
• /
• 1990

홍수기중의 실시간 저수지 운영을 위해서는 매시간 on-line으로 입력된 자료와 예측치로부터 시간별 최적방류량을 구해야 한다. 이를 위해서 댐하류의 홍수피해를 최소화하고 홍수 말기의 용수보존을 고려하는 무의 모형의 기법을 발표한 바 있다. 본 논문에서는 홍수시의 대청댐의 단일저수지 운영을 위해 모형을 적용하고 결과를 검토하며, 과거의 측정된 유입량과 방류량자료도 검토한다. 초기저수위를 달리하여 각 재현 기간별 홍수수문곡선을 다루고, 강우유출 모형으로부터 얻은 예측유입량을 구하여 운영한 뒤에 실제값과 비교하였다. 연구결과에 의하면 예측유입량의 불확실성을 고려하기 위해 위험계수를 적용하면 홍수조절용량을 효율적으로 이용할 수 있다.

• 전기학회논문지
• /
• 제63권2호
• /
• pp.297-305
• /
• 2014

Nowadays new water supply projects have been on the decline as the water-power constructions have saturated, which means that the existing power equipment have slowly aged and they require more efforts to maintain the system performance. An effective asset management method of power equipment has become a great necessity from both economical and technical aspects. To be balanced, the asset management should look into all three parts: management, engineering, and information. The purpose of this paper is to study a Risk-Based Maintenance (RBM) matrix method through the deterioration evaluation algorithm for an efficient reliability assessment of oil-immersed power transformers by considering both asset management and technical evaluation. Make use of this result, the equipment will be decided to be replace or repair otherwise on service.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2007년도 학술발표회 논문집
• /
• pp.1244-1248
• /
• 2007

This study aims at investigating the in situ applying grass concrete system in river environments which widely used nowadays and reviewing the effect and flow resistance for grass concrete structure through the physical experiments by hydraulic model test and developing application method in river bed which has rigid flood resistance. Grass concrete structure has been independently tested under high velocity flow under the super critical condition, as well as sud critical flow measuring velocity and water surface elevation along the cross section. This results shows grass concrete system is also suited to use in aggressive river environments such as repairing a flood damaged embankment that had placed at risk the adjacent drainage channel with vegetation.

• 한국수자원학회논문집
• /
• 제50권4호
• /
• pp.277-288
• /
• 2017

본 연구에서는 발생가능한 홍수시나리오를 기반으로 하천제방의 복합위험도를 산정하고자 하였다. 이를 위해 불확실성을 고려한 수문학적/수리학적/지반공학적의 위험도를 각각 MCMC (Markov Chain Monte Carlo), MCS (Monte Carlo Simulation), FOSM (First-Order Second Moment) 기법을 활용하여 해석하였으며, 이들 각각의 확률을 연계하여 결합확률 형태로 나타내었다. 적용대상 유역은 낙동강에 위치한 강정고령보를 기점으로 상 하류 12.5 km 구간으로 선정하였으며, 구간내의 총 6구간의 제방이 포함된다. 수문시나리오는 제방 월류가 발생하는 100년/200년 빈도 신뢰구간 상한치(97.5%)의 홍수량이 사용되었고, 이에 따른 홍수위 해석을 수행하여 월류위험도를 산정하였으며 월류가 발생하지 않는 구간에서는 침투, 사면안정, 수위급강하 등 제방의 지반공학적 위험도를 산정하였다. 기존 결정론적 위험도 해석보다 확률론적 위험도 해석에 의한 복합위험도가 제방설계에 보다 안정적, 경제적인 상승효과를 가져올 수 있을 것이며, 향후 수변구조물 설계에 지표로 사용될 수 있을 것으로 기대된다.

• Journal of Ecology and Environment
• /
• 제36권1호
• /
• pp.89-94
• /
• 2013

Diatoms have become an integral part of the UK's freshwater monitoring strategy over the past two decades, mostly in response to increasingly stringent European Union (EU) legislation. The use of diatoms is based on strong correlations between diatom assemblages and environmental variables, and from knowledge of the "expected" (= "reference") state of each river. The nationwide overview of the ecological health of rivers this gives allows those stretches of rivers which fail to meet EU criteria to be identified. This, in turn, allows appropriate remediation measures to be planned. Because diatom assemblages vary in space and time, even within a single water body, effective use of diatoms requires a consistent approach in order to minimise uncertainty. This includes the use of methods which comply with European Standards, a training and accreditation scheme for analysts, and a suite of quality assurance methods. Those aspects of uncertainty that cannot be readily controlled have been quantified and all estimates of ecological status are accompanied by the appropriate "confidence of class" and "risk of misclassification". This, in turn, helps planners prioritise those locations which are most likely to benefit from remediation.

• Advances in environmental research
• /
• 제6권4호
• /
• pp.281-299
• /
• 2017

Single (0.005 M DTPA), sequential (six-step) and kinetic (0.05 M EDTA) extractions were performed to assess Cd, Cr, Cu, Ni, Pb, and Zn mobilization and their potential ecological risks in Abuja (Nigeria) water (WTS) and wastewater (WWTS) treatment sludges. Total metal levels (mg/kg) in WTS and WWTS, respectively were: Cd(3.67 and 5.03), Cr(5.70 and 9.03), Cu(183.59 and 231.53), Ni(1.33 and 3.23), Pb(13.43 and 17.87), Zn(243.45 and 421.29). DTPA furnished metal extraction yields (%) in WTS and WWTS, respectively as: Cd(11 and 6), Cr (15 and 7), Cu(17 and 13), Ni(23 and 3), Pb(11 and 12), and Zn(37 and 33). The metals were associated with the soluble/exchangeable, carbonate, Mn/Fe-oxide, organic matter and residual forms to varying degrees. Kinetic extractions cumulatively leached metal concentrations akin to the mobilizable fractions extracted sequentially and the leaching data fitted well into the Elovich model. Metal mobilities were concordant for the three leaching procedures and varied in the order:WTS>WWTS. Calculated ecological risk indices suggested moderate and considerable metal toxicity in WTS and WWTS, respectively with Cd as the worst culprit. The findings may be useful in predicting heavy metals bioavailability and risks in the sludges to guide their disposal and use in land applications.

• 한국수자원학회논문집
• /
• 제46권1호
• /
• pp.35-45
• /
• 2013

본 논문에서는 통합홍수위험관리 측면에서 지역의 홍수위험도에 따라 지구를 구분할 수 있는 홍수위험지수(Flood Risk Index, FRI)의 산정 및 적용방안을 제시하고자 하였다. 낙동강 유역에대하여 시 군 구 단위의 공간해상도로 홍수위험지수(FRI)를 산정하기 위해 P-S-R(Pressure-State-Response) 구조로 분류하여 3개의 홍수지수인 압력지수(PI), 현상지수(SI), 대책지수(RI)를 대표하는 총 17개 세부지표들을 엄선하였다. 세부지표들은 각기 다른 범위와 단위로 측정된 값이므로, T-Score 방법을 사용하여 동일한 범위로 변환되었다. 또한 엔트로피(Entropy) 가중치 산정방법에 의한 가중치를 사용하여 가중치 적용에 따른 주관적인 판정을 최소화하였다. 압력지수(PI), 현상지수(SI), 대책지수(RI)의 3개 지수를 통합하여 지역의 전반적인 홍수위험 상태를 파악할 수 있는 홍수위험지수(FRI)를 산정하고, 가중치 적용 유 무에 따른 홍수위험지수 산정결과와 2010년에 고시된 자연재해위험지구 중 침수위험지구와의 비교를 통해 제안된 홍수위험지수의 적용성을 검토하였다. 충분히 검증된 홍수위험지수를 활용하면 과거 홍수의 원인 및 현상별 홍수재해에 대하여 지역적 방재대책 수립이 가능할 것이라 기대된다.

• 한국대기환경학회지
• /
• 제8권4호
• /
• pp.269-276
• /
• 1992

인체에 영향을 미치는 중금속은 대개 환경중에서 음식물, 공기, 먼지 및 음료수를 통하여 축적된다. 본 연구는 중금속중 납이 인체에 미치는 유해정도를 평가하기 위하여 서울과 여주등 대기중 납농도가 차이가 나는 지역주민들의 혈액중 납농도를 측정하여 Bio kinetic Model을 이용 납에 대한 인체의 위해성 정도를 알아보았으며 그 결과는 다음과 같다. - 지역별로는 혈액중 납농도가 별다른 차이를 보이지 않았으나 나이와 성별에 따라서는 다소 차이가 나고 있다. - 또한 혈액중 납농도는 log normal 분포를 나타내고 있음. - 기하표준편차는 1.2 $\sim$ 1.3 정도의 값으로 미국 EPA에서 추정한 1.31 $\sim$ 1.41의 값보다 약간 적은 값을 나타냈다.