• Journal of Korea Water Resources Association
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• v.33 no.6
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• pp.733-744
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• 2000

Due to the randomness of reservoir inflow and supply demand it is not easy to establish an optimal reservoir operation rule. However, the operation rule can be derived by the implicit stochastic optimization approach using synthetic inflow data with some demand satisfied. In this study the optimal reservoir operation which was reasonably formulated as Linear Tracking model for maximizing the hydro-energy of seven reservoirs system in the Han river was performed by use of the optimal control theory. Here the operation model made to satisfy the 2001st year demand in the capital area inputted the synthetic inflow data generated by multi-site Markov model. Based on the regressions and statistic analyses of the optimal operation results, monthly reservoir operation rules were developed with the seasonal probabilities of the reservoir stages. The comparatively larger dams which would have more controllability such as Hwacheon, Soyanggang, and Chungju had better regressions between the storages and outflows. The effectiveness of the rules was verified by the simulation during actually operating period.period.

• Journal of Korea Water Resources Association
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• v.32 no.5
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• pp.579-591
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• 1999

The operation of a reservoir system is necessary for establishing the operation rule as well as designing the reservoirs for water resources planning or management. Increasingly complex water resource systems require more advanced operation techniques. As a result, various techniques have been introduced and applied until now. In this study Linear Tracking model based on optimal control theory is applied to the operation of the largest scale multi-reservoir system in the Han river and its applicability proved. This system normally supplies the water resources required downstream for hydro-power and plays a role in satisfying the water demand of the Capital region. For the optimal use of the water resources the Linear Tracking model is designed with the objective to maximize the hydro-power energy subject to the water supply demand. The multi-reservoir system includes the seven main reservoirs in IIan river such as Hwachon, Soyanggang, Chunchon, Uiam, Cheongpyong, Chungju and Paldang. These reservoirs have been monthly operated for the past 21 years. Operation results are analyzed with respect to both hydro"power energy and water supply. Additionally the efficiency of the technique is assessed.sessed.

• Journal of Korea Water Resources Association
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• v.34 no.6
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• pp.617-625
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• 2001

Peace dam constructed against the water attack had stopped in the first step, linked with Hwacheon dam through bypass tunnels and had an effect of flood surcharging in its pocket on Hwacheon dam downstream. To study the utility of Peace dam, the flood control effects of Peace dam and the restricted water level (RWL) in Hwacheon dam were reviewed and identified with operating Hwacheon dam system. Analysing the results the ideas of expanding the usability of the water resources in Hwacheon dam system were suggested. To do that, the criteria and the model of reservoir operation were established frist and the optimization of the operation have done. Based on the results the performance of the optimization was evaluated as an reference coefficient with relative value of the registered data to the optimized. And examining several alternatives for the RWL in Hwacheon reservoir operation made more feasible RWL suggested. And its economic benefit was also reckoned.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.2
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• pp.141-149
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• 1993

Production of hydro-energy is random in its output amount due to the characteristics of the reservoir inflows. Therefore, it is necessary to provide the rationality in determining the amount of energy for a supply contract. This study presents a methodology for determining reasonably reliable amount of the energy supply considering the energy sale-incomes associated with the penalties which are subject to inflow-reliabilities. The objective function consists of the returns of energy sales and the risk-loss function to reflect statistically relevant risks. A range of the coefficient of the risk-loss function was figured out by its sensitivity analysis. The risk-loss herein means the penalty which should be paid by the energy supplier in case that the level of the energy supply is behind the contracted amount. And the reliability of reservoir inflow is defined by the exceedance probability of the inflow. The log-normal distribution was accepted as the probability density function of monthly inflows on the level of significance at 5%. Golden-ratio searching was applied to identify the optimal reliability and Incremental Dynamic Programming was used to maximize generation of the hydro-power energy in reservoir operation. The algorithm was the applied to the Daechung multi-purpose reservoir and hydro-power plant system in order to verify its usefulness.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.174-174
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• 2020

현재 4차 산업혁명은 산업 전 분야에 걸쳐 일어나고 있다. 농업용수 분야에서도 데이터를 활용한 수요자 중심의 지능형 물 관리사업 뿐만 아니라 일정규모 이상의 저수지 및 양수장에 대하여 농업용수 공급량 측정을 위한 계측기 설치사업이 추진 중에 있다. 그러나 현재까지 설치된 계측장치들의 활용방안에 대해서는 뚜렷한 성과가 도출된 바 없기에 농업용수 계측장치들의 활용방안에 대한 깊이 있는 연구가 필요한 실정이다. 이에 본 연구에서는 충북 진천군 소재 무수저수지 유역을 대상으로 농업용수 계측정보를 활용하여 관개용수의 최적 관리방안을 모색하고자 하였다. 농업용 저수지의 공급량, 용수간선의 수문개도율에 따른 각각의 시나리오를 설정하고 시나리오별 목적함수를 계산하여 농업용수의 최적 관리를 위한 시설물조작 알고리즘을 도출하였다. 뿐만 아니라 관개구역 내 수리시설물, 영농방식, 용수공급현황 등의 조사를 통해 농업용수 관개수로망을 구성하고 수리해석을 실시하여 농업용수 최적관리 알고리즘의 적용성을 검토하였다.

• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.2
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• pp.44-55
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• 1994

This paper describes the development of real-time irrigation reservoir operation models that adequately allocate available water resources for paddy rice irrigation. Water requirement deficiency index(WRDI) was proposed as a guide to evaluate the operational performance of release schemes by comparing accumulated differences between daily release requirements for irrigated areas and actual release amounts. Seven reservoir release rules were developed, which are constant release rate method (CRR), mean storage curve method(MSC), frequency analysis method of reservoir storage rate(FAS), storage requirement curve method(SRC), constant optimal storage rate method (COS), ten-day optimal storage rate method(TOS), and release optimization method(ROM). Long-term forecasting reservoir operation model(LFROM) was formulated to find an optimal release scheme which minimizes WRDIs with long-term weather generation. Rainfall sequences, rainfall amount, and evaporation amount throughout the growing season were to be forecasted and the results used as an input for the model. And short-term forecasting reservoir operation model(SFROM) was developed to find an optimal release scheme which minimizes WRDIs with short-term weather forecasts. The model uses rainfall sequences forecasted by the weather service, and uses rainfall and evaporation amounts generated according to rainfall sequences.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.302-302
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• 2022

최근 태풍, 집중호우로 인한 홍수피해가 빈번히 발생함하고 있다. 특히 상류에 저수지가 있을 경우 홍수조절을 통해 하류지역의 홍수피해를 저감하기도 하지만 급작스런 방류량의 증가 등으로 인해 하류지역의 피해가 증가되는 경우도 있다. 따라서 하류지역 홍수피해 저감을 위해 저수지의 홍수관리기능에 대한 관심도가 높아지고 있다. 대규모 다목적댐의 경우 다양한 저수지운영룰을 통해 수문을 운영하고 있어 홍수조절기능을 충분히 수행하고 있지만, 농업용저수지는 홍수관리에 있어 수문조작 전문성의 부족과 운영룰의 미정립 등으로 인해 취약성을 가지고 있는 상황이다. 본 연구에서는 수문이 설치된 1백만m³이상의 저수지 중 성주저수지를 연구대상저수지로 선정하였다. 비상수문을 통한 사전방류방안과, 저수지운영을 연구하여 농업용저수지의 홍수조절용량 확보를 위한 사전방류방안에 대해 연구하였다. 저수지운영은 Auto ROM을 적용하였고 홍수조절용량 확보를 위하여 홍수기 수위관리기법 중 사전방류기법을 채택하였다. 사전방류기법은 모의기법에 의한 사전방류와 최적화기법에 의한 최적사전방류량을 결정하는 방법으로 연구하였다. 홍수기의 제한수위는 유효저수량의 70%인 EL.179.7m, 65%인 EL.178.8m, 60%인 EL.177.8m로 설정하여 분석하였다. 모의기법에 의한 사전방류방법은 초기수위는 만수위에서부터 1.0m씩 감소하였고, 비상수문은 0.5m씩 개방하여 4.0m까지 개방 하였다. 사전방류의 시간은 24hrs, 48hrs를 적용하였다. 최적화기법에 의한 사전방류방법은 초기수위는 모의기법과 동일하고 목표수위를 제한수위(70%, 65%, 60%)가 되는 최적방류량을 산정하고 최적방류량을 방류할 수 있는 수문의 개방높이를 분석하였다. 2012년, 2020년의 호우사상에 대해 사전방류가 없는 경우와 모의기법, 최적화기법에 의한 사전방류결과를 적용한 경우를 비교하여 검토하였다. 그 결과 제한수위 70%를 유지할 경우 2012년은 모의기법이 5.6%, 최적화기법이 5.4%의 방류량 감소효과가 있으며 2020년은 모의기법이 9.0%, 최적화기법이 8.8%의 방류량 감소효과가 있는 것으로 검토되었다.

• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.1
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• pp.63-72
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• 1994

The objective of the study is to develop weather generators for daily rainfall and small pan evaporation and to test the applicability with recorded data. Daily rainfall forecasting model(DRFM) was developed that uses a first order Markov chain to describe rainfall seque- nces and applies an incomplete Gamma function to predict the amount of precipitation. Daily evaporation forecasting model(DEFM) that adopts a normal distribution function to generate the evaporation for dry and wet days was also formulated. DRFM and DEFM were tested with twenty year weather data from eleven stations using Chi-square and Kolmogorov and Smirnov goodness of fit tests. The test results showed that the generated sequences of rainfall occurrence, amount of rainfall, and pan evaporation were statistically fit to recorded data from eleven, seven, and seven stations at the 5% level of significance. Generated rainfall data from DRFM were very close in frequency distri- bution patterns to records for stations all over the country. Pan evaporation for rainy days generated were less accurate than that for dry days. And the proposed models may be used as tools to provide many mathematical models with long-term daily rainfall and small pan evaporation data. An example is an irrigation scheduling model, which will be further detailed in the paper.

• Proceedings of the Korea Water Resources Association Conference
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• 1986.07a
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• pp.147-158
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• 1986

본 논문에서는 북한강 수계의 소양강댐 및 최근에 건설된 남한강 수계의 충주댐의 홍수조절 모형을 개발하였으며, 그 방법으로는 mini-max Dynamic Programming(DP)에 의한 Optimization기법을 사용하였다. 즉 각댐의 유입량을 이용하여 소양강댐 및 충주댐에서의 최대 방류량을 최소화시키는 목적 함수를 사용하였으며, 각 댐 및 하도의 특성에 따른 제약 조건을 고려하였다. DP에 의한 소양강댐 및 충주댐의 최적 운영 결과를 조절율과 이용율을 사용하여 Simulation방법중 Technical ROM, Rigid ROM, Linear Decision Rule(LDR)과 비교한 결과 모든 빈도에 대해서 DP에 의한 방법이 더 좋은 것으로 나타났다. 소양강댐의 각 빈도별 유입량에 대한 방류 형태중, 5년 빈도의 경우에는 방류를 전혀 하지 않아도 저수위가 홍수위 198m를 넘지 않으므로 사실상 5년 빈도의 홍수에 대해서는 저수지 조작이 필요없다. 충주댐의 각 빈도별 유입량에 대한 방류 형태는 초반부와 후반부에서는 방유량-유입량으로 방출하고 중반부에서는 일정한 양을 방류한다. 이에 따라 저수위도 초반부와 후반부에서는 각각 제한수위 138m와 홍수위 145m로 유지된다.

• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.3
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• pp.47-59
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• 1994

The irrigation reservoir operation models developed were tested with weather and field data, and the sensitivity of the water requirement deficiency indices(WRDI) were checked with different initial reservoir storages, irrigated areas, and other water uses from the reservoir storage. Seven reservoir release rules were applied to Yongseol Reservoir. Twenty year WRDIs were computed to check performances of those reservoir release rules. Mean WRDIs were 138, 198, 198, 200, 240, 344, and 1033mm for ROM, TOS, COS, CRR, MSC, FAS, and SRC, respectively. The results indicated that ROM contributes consistently to higher operation efficiencies of an irrigation reservoir. The test results of LFROM and SFROM showed that reservoir operation with the proposed optimization technique ROM would be better suited for an irrigation district than those with the other rules. And the proposed model could be used as a tool to improve reservoir operations.