• KCID journal
• /
• v.5 no.1
• /
• pp.20-31
• /
• 1998

The Power transformation, the modified Power transformation, the logarithmic transformation, the square-root logarithmic transformation, the SMEMAX transformation, the Extreme value type III, the Weibull, the log Pearson type III, the lognormal distributi

• 수도
• /
• s.5
• /
• pp.30-33
• /
• 1975

• Water for future
• /
• v.28 no.3
• /
• pp.63-66
• /
• 1995

• Water for future
• /
• v.21 no.2
• /
• pp.165-167
• /
• 1988

• Water for future
• /
• v.52 no.5
• /
• pp.6-10
• /
• 2019

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.11 no.4
• /
• pp.113-119
• /
• 1991

In the present study, a methodology has been established for water budget analysis of a river basin for which monthyl rainfall and evaporation data are the only available hydrologic data. The monthly rainfall data were first converted into monthyl runoff data by an empirical formula from which long-term runoff data were generated by a stochastic generation mothod. Thomas-Fiering model. Based on the generated long-term data low flow frequency analysis was made for each of the oberved and generated data set, the low flow series of each data set being taken as the water supply for budget analysis. The water demands for various water utilization were projected according to the standard method and the net water consumption computed there of. With the runoff series of the driest year of each generated data set as an input water budget computation was made through the composite reservoirs comprised of small reserviors existing in the basin by deficit-supply method. The water deficit computed through the reservior operation study showed that the deficit radically increases as the return period of low flow becomes large. This indicates that the long-term runoff data generated by stochastic model are a necessity for a reliable water shortage forecasting to cope with the long-term water resourse planning of a river basin. F.E.M. program (ADINA) is also presented herein.

• Journal of Korea Water Resources Association
• /
• v.41 no.11
• /
• pp.1143-1152
• /
• 2008

Korea is located in a monson area, so that 2/3 of precipitation is fallen down in rainy season and dry season has few rainfall. Also, water quality gets worse during dry season by shortage of water. In this paper, the method, which is a physical way to improve water quality by dilution through over supplied water from big reservoir or dam, is analyzed at Han-river basin. For the sake of the analysis, the basin is divided in 33 catchments and each catchments' natural flow is simulated by SWAT-K and the future water demand is estimated by using statistics data. It is considered that Han-river basin has two big reservoirs(Chung-ju dam, So-yang gang dam) and potential discharge by dam is calculated through case of supply water from each dam and supply water from both dams.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2008.05a
• /
• pp.1713-1716
• /
• 2008

최근 배출되는 미량유해물질로 1991년 페놀, 2004년 1,4-다이옥산, 2006년 퍼클로레이트 검출 등 빈번하게 원수수질 오염사고가 발생하고 새로운 미량유해 화학물질의 배출이 우려됨에 따라, 일부 시민단체, 시의회, 언론 등에서 깨끗하고 안전한 상수원수 확보를 위한 근본적인 대책을 요구하는 목소리가 커지고 있다. 이에 대한 대책의 일환으로 취수원 이전에 대한 타당성 등이 검토되고 있다. 이러한 요구를 바탕으로 본 연구에서는 K-WEAP 모형을 이용하여 낙동강수계 물수지 분석을 실시하였다. 관련된 기존자료를 이용하여 용수수요량을 산정하였으며, 갈수량시 물수지 분석을 실시하였다. 연구에 사용된 K-WEAP 모형은 SEI-B(Srockholm Environment Institute, Boston Center)에서 개발된 WEAP에 기반을 두고 우리나라에 특성에 맞게 모의형태를 개선하고 한글화한 모형으로 분석대상 지역으로서 도시지역과 농업지역, 단일 소유역이나 복잡한 하천유역의 물 수요-공급 시스템에 적용할 수 있다. 또한 K-WEAP 모형은 용수목적별 수요량 분석, 물 절약, 수리권과 배분 우선순위, 지하수와 하천유량 모의, 저수지 운영, 수력발전, 오염물질 추적, 생태계 필요수량 분석과 같은 광범위한 부문의 문제들까지 다룰 수 있다. 본 연구에서 물수지 분석에 사용된 대상구간은 낙동지점에서 고령교지점까지 약 120km이며, 낙동강에 유입되는 지류로는 감천과 금호강을 대상에 포함하였다. 대상구간에 대해서는 3가지의 시나리오를 바탕으로 모의를 진행하였다. 선정된 3가지 시나리오는 현재의 대구 인근지역의 취수와 방류를 고려하는 상태와 현실가능성이 있는 2가지의 대안에 대해서 분석을 실시해 보았다. 대안들은 각각의 대구 취수시설을 구미 상류로 이전하여 취수하는 상황과 구미지역 및 칠곡지역의 방류구 시설을 하류로 이전하여 방류하는 상황으로 가정하여 분석을 실시하였다. 분석결과 현재 상태의 시나리오에서만 갈수기시 만족할 만한 결과를 보여주었고 나머지 2가지의 시나리오에서는 유량이 부족함을 나타났다. 현재의 상태를 모의한 시나리오를 제외한 시나리오의 분석에서는 갈수기 시에 물 부족을 겪게 된다. 이는 낙동강 상류에서 추가방류가 없으면 해결되지 못하는 상황으로 다른 대안들(신규 댐 방류 등)에 대한 추가적인 시나리오 분석이 필요할 것으로 판단된다.

• Journal of Korea Water Resources Association
• /
• v.33 no.1
• /
• pp.3-14
• /
• 2000

The primary objective of this study is to estimate the suitable flow in need for conservation and restoration of the fish habitat in running water ecosystem, which has very important status in the instream flow for stream environment. Year, monthly low flows are estimated to properly maintain the fish habitat. Water depth and velocity are simulated, and also water temperature and Dissolved Oxygen(DO) are predicted at gradually varied flow using estimated low flows. These simulated conditions for each low flow are graphically compared with the requirements to maintain fish habitat at each life stage. These processes were applied to 3 riffle transects located at Dalcheon(Dal stream) in the South Han river. Pirami (Zacco platypus) was selected as a representative fish species in Dalcheon. It was shown that the suitable flow for maintaining the representative fish habitat at each life stage depends on hydraulic conditions rather than water quality conditions, and the flow ranges from the 10-year minimum low flow to consecutive 7-day 2.33-year low flow.w flow.

• Journal of Korea Water Resources Association
• /
• v.32 no.3
• /
• pp.265-279
• /
• 1999

In this study, one of the techniques on the extension of low flow series has been developed, in which the daily streamflows were simulated by the Tank model with the input of extended daily rainfall series which were stochastically generated by the Markov chain model. The annual lowest flow serried for each of the given durations were formulated form the simulated daily streamflow sequences. The frequency of the estimated annual lowest flow series was analyzed. The distribution types to be used for the frequency analysis were two-parameter and three-parameter log-normal distribution, two-parameter and three-parameter Gamma distribution, three-parameter log-Gamma distribution, Gumbel distribution, and Weibull distribution, of which parameters were estimated by the moment method and the maximum likelihood method. The goodness-of-fit test for probability distribution is evaluated by the Kolmogorov-Sminrov test. The fitted distribution function for each duration series is applied to frequency analysis for developing duration-low flow-frequency curves at Yongdam Dam station. It was shown that the purposed technique in this study is available to generate the daily streamflow series with fair accuracy and useful to determine the probabilistic low flow in the watersheds having the poor historic records of low flow series.