• 물과 미래
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• 제4권1호
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• pp.51-58
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• 1971

Hydrologic data serve as an input to the water resources system. An adequate analysis of hydrologic data is one of the most important steps in the planning of the water resources development program. The natural hydrologic processes, which produce the hydrologic data, are truely 'stochastic' in the sense that natural hydrologic phenomena change with time in accordance with the law of probability as well as with sequential relationship between their occurrences. Therefore, the stochastic approach to the analysis of hydrologic data has become more popular in recent years than the conventional deterministic or probabilistic approach. This paper reviews the mathematical models which can adequately simulate the stochastic behavior of the hydrologic characteristics of a hydrologic system. The actual application of these models in the analysis of hydrologic records(precipipitation and runoff records in particular) is also presented.

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2003년도 추계정기총회 및 국제심포지엄
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• pp.122-128
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• 2003

To develop a Mg-Zeolite for simultaneous recovery of the N and the P from sewage water, the natural zeolite was treated with 20% $MgCl_2$ solution by changing the pH the temperature and the treating time of the solution. And the contents of Ca Fe Na K Mg of Mg-Zeolite were analyzed by ICP. The optimum treatment condition for Mg-Zeolite was induced to pH 7.0 $50^{\circ}C$ in 20% $MgCl_2$ solution and for 80min treatment. And the Na and the K ions in natural zeolite are significant factors for Mg exchange in the zeolite.

• 한국환경농학회지
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• 제39권3호
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• pp.197-203
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• 2020

BACKGROUND: Most lakes have increased concerns about water pollution due to the inflow of non-point sources caused by human activities. Therefore, the lake water quality survey was conducted in order to propose effective plans for water quality management by analyzing the characteristics of lakes and the change of water quality. METHODS AND RESULTS: In order to investigate the physicochemical water quality in Daedong lake, water quality analysis was undertaken from July 2018 to June 2019. Water temperature was ranged from 7.8 to 34.3℃ and pH varied from 6.9 to 10.2. The concentration of Dissolved oxygen, Suspended solid, Biochemical Oxygen Demand (BOD), and Chemical Oxygen Demand (COD) were 5.6 ~ 17.2 mg/L, 2.4 ~ 35.3 mg/L, and 4.5 ~ 15.1 mg/L, and 0.9 ~ 2.8 mg/L, respectively. The Total Nitrogen (T-N) concentration ranged from 0.974 ~ 2.126 mg/L, and Total Phosphorus (T-P) concentration ranged from 0.014 ~ 0.057 mg/L. The Chlorophyll-a (Chl-a) ranged from 2.7 ~ 37.9 mg/㎥. Through Carlson TSIm assessment using T-P and Chl-a results, evaluating trophic state, Daedong lake was evaluated as mesotrophic. CONCLUSION: Water pollution management plan needs such as nutrient removal technology and nonpoint source management for prevention of eutrophication in Daedong lake.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2007년도 학술발표회 논문집
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• pp.855-859
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• 2007

It is essential to obtain accurate and highly reliable streamflow data for water resources planning, evaluation and management as well as design of hydraulic structures. A new discharge estimation method, which is named 'non-dimensional velocity distribution and index-velocity method,' was proposed in this research. This method showed very close channel discharges which were calculated with the exiting velocity-area method. When velocity-area method is used to estimate channel discharge, it is required to observe point velocities at every desired point and vertical using a current meter like Price-AA. However 'non-dimensional velocity distribution and index-velocity method' is used, it become optional to observe point velocities at every desired point and vertical. But this method can not be applied for the cases of very complex and strongly asymmetric channel cross-sections because non-dimensional velocity distribution by entropy concept may be quite biased from that of natural rivers.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2020년도 학술발표회
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• pp.124-124
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• 2020

This study proposes a framework to evaluate extreme drought using the natural drought index and hot spot analysis. The study area was South Korea. Data were used from 59 automatic synoptic observing system stations. The variable infiltration capacity model was used for the period from 1981 to 2016. The natural drought index was constructed from precipitation, runoff and soil moisture data, which reflect the water cycle. The average interval, duration and severity of extreme drought events were determined following Run theory. The most extreme drought period occurred in 2014-2016, with 46 of 59 weather stations exhibition drought conditions and 78% exhibition extreme drought conditions. The Inje and Seosan station exhibited the longest drought duration of 6 months, and the most severe drought was 5 times higher than the extreme drought severity threshold. The hot spot analysis was used to explore the extreme drought conditions and showed an increasing trend in the middle and northeastern parts of South Korea. Overall, this study provides water resource managers with essential information about locations and significant trends of extreme drought.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(1)
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• pp.698-699
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• 2005

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권4호
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• pp.31-40
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• 2015

Various types of inorganic and organic colloids are present in natural water including groundwater. Previous studies showed that Fe, Mn and Al are colloid-forming elements and dissolved concentrations can be erroneous for these elements if water samples are not properly filtered. Dissolved concentrations of elements including Ca, Na, Mg, K, Fe, Mn, Si and Al in groundwater from alluvial and bedrock aquifers, and surface water near Nakdong River were determined to evaluate effects of colloids on dissolved concentrations in natural water samples using various pore sizes of filters. Groundwater is mostly anoxic and have elevated concentrations of Fe and Mn, which provides a unique opportunity to observe the effects of colloids on dissolved concentrations of colloid-forming elements. Membrane filters with four kinds of pore sizes of 1000 nm, 450 nm, 100 nm, and 15 nm were used for filtration of water samples. Concentrations of dissolved concentrations in each filtrate did not show significant differences from 1000 nm to 100 nm. However, concentrations of all elements considered were decreased in the filtrates obtained using 15 nm pore size filters by 10 to 15% compared to those using 450 nm except for bedrock groundwater. Al in surface water showed a distinct linear decrease with the decrease of filter pore sizes. These results showed that 100 nm pore size had little effect to remove colloidal particles in alluvial groundwater and surface water in our study. In contrast, significant concentration decreases in 15 nm pore size filtrates indicate that the presence of 15 to 100 nm colloidal particles may affect determination of dissolved concentrations of elements in natural water.

• 한국환경과학회지
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• 제22권12호
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• pp.1661-1669
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• 2013

This study conducted a laboratory simulation using artificial and natural rainfall in order to investigate the runoff characteristics of livestock resources through the analysis of the surface runoff water and infiltration water by rainfall intensity and fertilization level. Cattle manure and pig liquid fertilizer was used as livestock resource. As a result of this study, it was observed that the surface runoff occurred over 32 mm/hr rainfall intensity, and flow rate of the surface runoff water and the runoff ratio of contaminant parameters from livestock resource was increased, as rainfall intensity was stronger. With doubled fertilization level, T-N increased in compost and the amount of $COD_{Mn}$ runoff also considerably increased in liquefied fertilizer. In the case of natural rainfall, the runoff ratio of T-P clearly increased in compost and the T-N of final surface runoff ratio in compost and liquefied fertilizer was ranged from 0.13047 to 0.13623 with stronger rainfall intensity.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.160-160
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• 2022

Floods are the most common natural disasters and are annually causing severe destructions worldwide. Human activities, along with expected increased extreme precipitation patterns as a result of climate change enhance the future potential of floods. There are proven evidence that infrastructure based responses to flood disaster is no longer achieving optimum mitigation and have created a false sense of security. Nature-based solutions(NBS) is a widely accepted sustainable and efficient approach for disaster risk reduction and involves the protection, restoration, or management of natural and semi-natural ecosystems to tackle the climate and natural crisis. Adoption of NBS in decision-making, especially in developing nations is limited due to a lack of sufficient scenario-based studies, research, and technical knowledge. This study explores the knowledge gap and challenges on NBS adoption with case study of developing nation, specially for flood management, by the study of multiple scenario analysis in the context of climate, land-use change, and policies. Identification and quantification of the strength of natural ecosystems for flood resilience and water management can help to prioritize NBS in policymaking leading to sustainable measures for integrated flood management.

• 한국수자원학회논문집
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• 제46권7호
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• pp.719-733
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• 2013

본 연구에서는 죽산천 유역에 대해 지표수와 지하수의 통합거동을 유역 스케일로 장기간 모의할 수 있고 양수정의 공간분포 및 저수지 운영을 복합적으로 고려할 수 있는 유역단위 통합수문해석모형 SWAT-MODFLOW를 적용하여 지하수 양수 및 농업용 저수지가 하천유량에 미치는 영향을 평가하였다. 지하수 양수 및 농업용저수지 고려 유무에 따라 4가지 시나리오(1) 현 지하수 이용량 고려, 저수지 고려, (2) 현 지하수 이용량 고려, 저수지 미고려, (3) 지하수 이용량 미고려, 저수지 고려), (4) 지하수 이용량 미고려, 저수지 미고려(자연상태)를 구성하고 각 시나리오별로 하천유량의 변화를 모의한 결과, 죽산천 유역 출구부를 기준으로 지하수 양수로 인한 영향이 농업용 저수지에 의한 영향보다 상대적으로 크게 발생하였으며, 갈수량은 용수이용이 없는 자연 상태(natural flow)에 비해서 지하수 양수만의 영향으로 약 17%, 저수지만의 영향으로 약 11%, 양수 및 저수지의 복합영향으로 인해 약 23% 만큼 감소하는 것으로 분석되었다. 농업용 저수지로부터 떨어진 거리에 따른 하천유량의 변화를 평가하기 위해서 죽산천 본류를 따라 비갈수량을 산정한 결과, 저수지 관개용수의 회귀수 영향으로 하류로 내려갈수록 비갈수량이 증가하였으며, 죽산천 상류에 위치한 덕산 저수지로부터 약 6.5 km까지는 저수지의 영향이 상당히 미치는 것으로 분석되었다.