• Water for future
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• v.35 no.5
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• pp.51-59
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• 2002

In recent years the human impact on the environment becomes increasing lift threatening, calls for the better management of resources. In field of water quality of river flow, the best way to conserve water quality is specific efforts to control the pollutant loadings and treat the loadings in the basin to reduce the discharge of pollutant loadings to river. But in general the water quality influenced by the dam discharge. Especially in dry season, it is more dominant way to improve the water quality which contaminated with the pollutant loadings from the basin. The dam discharge amounts of the 2 dams in the Keum River that maintain the down stream water quality were estimated for the year of 1999, 2001, 2006, 2011, in case of irrigation and non-irrigation seasons. The pollutant loadings for the basin are estimated with the planning of treatment plants construction schedule for every sub-basins. The river flow rates were considered low flow as 2.33 year low flow and 10 year low flow. The QUAL2E model was used as a tool of simulation.

• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.4
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• pp.1-6
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• 2009

This study analyzed and evaluated the effect of agricultural water reduction by introducing automated agricultural water management using alternative cost approach. The approach is possible to evaluate none market property as an asset. The saved agricultural water was evaluated as none market property. As the alternative goods, Seongju and Donghwa dam, typical irrigation dams in domestic, were employed. The economic benefit from water saving effect of an automated agricultural water management was calculated as depreciation expense and maintaining cost of construction agricultural dam per saved agriculture water. As a result, the saved agriculture water was 8.5 million ton per year, and the economic benefit of it was $1.3{\sim}2.1$ million won.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.6
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• pp.109-118
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• 2003

As a fundamental research to establish a safety operation plan for irrigation dams, this study presents hydrologic analysis conducted in Sungju Dam watershed based on various rainfall data. Especially those reservoirs without flood control feature are widely exposed to the risk of flooding, a safe and optimized operation program need to be improved against arbitrary flooding. In this study, reservoir routing program was developed and simulated for reservoir runoff estimation using WMS hydrology model. The model simulated the variations of reservoir elevation under the condition of open or closed emergency gate. In case of closed emergency gate, water surface elevation was given as 193.15 m, and this value exceeds the dam crest height by 1.65 m. When the emergency gate is open, the increment of water surface elevation is given as 192.01 m, and this value exceeds dam crest height by 0.57 m. As an alternative plan, dam height increase can be considered for flood control under the PMP (Probable Maximum Precipitation) condition. Since the dam size is relatively small compare to the watershed area, sound protection can be expected from the latter option rather than emergency gate installation.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.24-24
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• 2023

This presentation highlights the IAHR book, recently published last April, of which the author is the editor-in-chief, on the historical water projects and traditional water technologies of international interest in the Asian region, addressing information on past water projects (mostly before the 20th century) in the regions that are technically and culturally of interest and educationally valuable. The book explores historical water projects in these regions, presenting technologies used at the time, including calculation and forecasting methods, measurement, material, labor, methodologies, and even water culture. Through this book, it is expected that the old Asian wisdom of "reviewing the old and learning the new" would be realized to a certain extent in modern planning and practice of water projects. The book comprises a lead article that the presenter authored and five Parts representing China, Japan, Korea, South Asia, and Southeast Asia, respectively, followed by an invited one from Uzbekistan. Throughout the book, it is found that historically the Asian monsoon, affecting the Indian subcontinent and Southeast and East Asian regions, induced rice cultivation. It fundamentally needs proper irrigation systems, including reservoirs (dams) and canals, water wheels, and even rain gauges. Flood risks have been more common in Asia than Europe under this climate condition, as recognized in history. To utilize and sometimes overcome these climate conditions, people built and managed many historical and grandiose water projects and invented and used localized but sophisticated water-related technologies in the Asian region.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.30-30
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• 2023

This study aims to establish the multi-reservoir operation system model in the Upper Mun River Basin which includes 5 main dams namely, Mun Bon (MB), Lamchae (LC), Lam Takhong (LTK), Lam Phraphoeng (LPP), and Lower Lam Chiengkrai (LLCK) Dams. The knowledge and AI technology were applied aiming to develop innovative prototype for SMART dam-reservoir operation in future. Two different sorts of reservoir operation system model namely, Fuzzy Logic (FL) and Constraint Programming (CP) as well as the development of rainfall and reservoir inflow prediction models using Machine Learning (ML) technique were made to help specify the right amount of daily reservoir releases for the Royal Irrigation Department (RID). The model could also provide the essential information particularly for the Office of National Water Resource of Thailand (ONWR) to determine the short-term and long-term water resource management plan and strengthen water security against flood and drought in this region. The simulated results of base case scenario for reservoir operation in the Upper Mun from 2008 to 2021 indicated that in the same circumstances, FL and CP models could specify the new release schemes to increase the reservoir water storages at the beginning of dry season of approximately 125.25 and 142.20 MCM per year. This means that supplying the agricultural water to farmers in dry season could be well managed. In other words, water scarcity problem could substantially be moderated at some extent in case of incapability to control the expansion of cultivated area size properly. Moreover, using AI technology to determine the new reservoir release schemes plays important role in reducing the actual volume of water shortfall in the basin although the drought situation at LTK and LLCK Dams were still existed in some periods of time. Meanwhile, considering the predicted inflow and hydrologic factors downstream of 5 main dams by FL model and minimizing the flood volume by CP model could ensure that flood risk was considerably minimized as a result of new release schemes.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1471-1475
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• 2005

현재 우리나라 관개용 댐의 농업용수는 논관개 용수를 위주로 하여 하천유지용수, 생활용수, 축산용수를 주 공급량으로 산정하고 있다. 그러나 극히 일부를 제외하고 밭에 대한 관개용수를 산정하여 공급하는 경우가 거의 없으며, 실제 현장에서도 수원공으로부터 체계적인 용수공급이 아닌 필요한 곳에 관정 등을 설치하여 지하수를 사용하고 있다. 본 연구에서는 밭관개 용수의 확보를 위하여 관개용 댐의 저수를 기간별로 관리모의 하였다. 이를 통해 용수의 신규 개발이 아닌 기존 용수의 저수 관리를 통하여 용수의 이용효율을 높일 수 있도록 하였다. 우리나라의 대표적 관개용 댐인 성주댐과 동화댐을 대상지구로 하여 논관개 용수와 같은 정상적 용수 공급에 영향을 주지 않으며, 추가적인 용수를 확보할 수 있도록 하였다. 이상의 결과론 성주지역 주요 밭작물 필요수량은 충분히 확보할 수 있었으며, 동화지역의 경우도 1998년과 2001년 같은 극심한 가뭄년을 제외하고 추가공급 가능량이 발생하는 것으로 분석되었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1228-1232
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• 2004

일반적으로 관개용 댐은 예비 방류기능이 부족하므로 저수지관리를 위한 수위 조절이 장시간에 걸쳐 계획적으로 이루어 져야한다. 본 연구는 성주유역을 내상으로 장기 물수지 분석과 빈도분석을 실시하여 관개용 댐의 기간별 적정 수위를 모의하였다. 현장에서 적용이 가능하도록 저수위 관리 기간을 4단계로 나누어 자기간의 관리 방법과 적정 수위를 제시하였다. 홍수기 전에는 수위를 낮추어 홍수를 대비할 수 있도록 하였으며, 홍수기 이후에는 이듬해 관개기 전까지 동계 만수위를 확보할 수 있는 수위와 연중 유지해야 하는 최저수위를 산정하였다. 이상의 결과로 $1998\~2002$년에 내하여 적용해본 길과, 관개기전 동계 만수위를 유지하였고, 물 부족 기간은 발생하지 않았으며, 2001년 가뭄과 2002년 태풍에 대한 피해를 최소화 할 수 있었다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.407-416
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• 2016

The purpose of this study is to develop regional regression models to estimate mean low flow for ungauged basins. The unregulated streamflow data observed at 12 multipurpose dams and 4 irrigation dams were analyzed for determining mean low flows. Various types of regression models were developed using the relationship between mean low flows and various sets of watershed characteristics such as drainage area, average slope, drainage density, mean annual precipitation, runoff curve number. The performance of each regression model for estimating mean low flows was assessed by comparison with the results obtained from the observed data. It was found that a regional regression model explained by drainage area, the mean annual precipitation, and runoff curve number showed the best performance. The regression model presented in this study also gives better estimates of mean low flow than the estimates by the drainage-area ratio method and the previous regression model.

• Journal of Korean Society on Water Environment
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• v.32 no.5
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• pp.433-441
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• 2016

Many large dams have been constructed for water supply, irrigation, flood control and hydropower in Korea for the last century. Meanwhile, recent studies indicated that the artificial reservoirs impounded by these dams are major sources of carbon dioxide (CO₂) to the atmosphere and relevant to global budget of green house gases. However, limited information is available on the seasonal variations of CO₂ evasion from the reservoirs located in the temperate monsoon regions including Korea. The objectives of this study were to estimate daily Net Atmospheric Flux (NAF) of CO₂ in Daecheong Reservoir located in Geum River basin of Korea, and analyze the influencing parameters that characterize the variation of NAF. Daily pH and alkalinity (Alk) data collected in wet year (2012) and dry year (2013) were used for estimating the NAFs in the reservoir. The dissolved inorganic carbon (DIC) was computed using the pH and Alk measurements supposing an equilibrium state among the carbonate species. The results showed seasonal variations of NAF; negative NAFs from May to October when the primary production of the reservoir increased with water temperature increase, while positive NAF for the rest of the period. Overall the reservoir acted as sources of CO₂ to the atmosphere. The estimated NAFs were 2,590 and 771 mg CO₂ m^-2d^-1 in 2012 and 2013, respectively, indicating that the NAFs vary a large extent for different hydrological years. Statistical analysis indicated that the NAFs are negatively correlated to pH, water temperature, and Chl-a concentration of the reservoir.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.11-17
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• 2012

The Waikato River is New Zealand's longest River, though relatively small on international scales. It drains the central North Island and has New Zealand's largest lake (Lake Taupo) at its headwaters. The upper reaches have sustained flows fed by large aquifers which are recharged by rainfall events providing relatively constant river flows, whereas the lower reaches respond more directly to rainfall events having more peaky flows after rainfall and extreme low flows during dry periods. Consumptive allocation from the river is relatively low with only about 3% of the mean annual flow being allocated. However, more than seven times the river's flow is allocated for non-consumptive purposes before discharging to the Tasman Sea. The majority of this non-consumptive allocation is for hydro power generation and as cooling water at both thermal and geothermal power stations which produce up to 25% of New Zealand's electricity. The upper half of the river has been heavily modified with the construction of eight dams for power generation. This has resulted in a succession of cascading dams replacing the previously uncontrolled river. The Waikato River also provides drinking water for Auckland City (NZ's largest city) and Hamilton City (NZ's 4th largest city). In recent years there has also been considerable growth in water requirements for pasture irrigation to support the intensification of dairy farming in the catchment. Operators of the power stations are concerned that any further consumptive allocation will further reduce their ability to generate electricity. The Waikato Regional Council, who is charged with managing the river and allocation of water, has recently set new rules for managing the conflicting allocation demands on the Waikato River. This has resulted in an end to further allocation of water where it results in a loss of water for electricity generation from renewable resources (fresh water and geothermal water). The exception to this is the prioritisation of water for municipal supplies ahead of other consumptive uses such as industries and irrigators.