• Journal of Korea Water Resources Association
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• v.37 no.8
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• pp.653-662
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• 2004

In this study, the method of Increasing the flood control as well as conservation effects is studied by joint operation of Hwacheon and Peace Dam. After completing the second phase of the construction of the Peace Dam, the dam crest height will be increased from 225m and the storage capacity will also be increased. If storage capacity is increased and gates are installed, it will assist not only flood control but also conservation of the entire Han river basin. Considering the change of conservation levels, the change of the restricted water level of the Hwacheon Dam in flood season, and the inflow change into the Peace Dam through the simulated reservoir operation, the annual average power of Hwacheon Dam with 95% reliability, annual firm power, the volume of water supply is calculated. As a result, when the conservation level of the Peace Dam and the restricted water level of the Hwacheon Dam are increased, the generation capacity will be improved. However, even though the inflow decrease, the generation capacity will not be affected. If the inflow decrease under the same conditions, the water supply capability will be reduced to the range from 35% to 40%. It is necessary to increase conservation level to keep the same water supply capability.

• Journal of Korea Water Resources Association
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• v.51 no.5
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• pp.425-438
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• 2018

Existing studies that analyze the causes and effects of water circulation use mostly rainfall - runoff models, which requires much effort in model development, calibration and verification. In this study, hydrological sensitivity analysis which can separate quantitatively the impacts by natural factors and anthropogenic factor was applied to the Hwacheon dam upper basin from 1967 to 2017. As a result of using various variable change point detection methods, 1999 was detected as a statistically significant change point. Especially, based on the hydrological sensitivity analysis using 5 Budyko based functions, it was estimated that the average inflow reduction amount by Imnam dam construction was $1.890\;billion\;m^3/year$. This results in this study was slightly larger than the those by existing researchers due to increase of rainfall and decrease of Hwacheon dam inflow. In future, it was suggested that effective water management measures were needed to resolve theses problems. Especially, it can be suggested that the monthly or seasonal analysis should be performed and also the prediction of discharge for future climate change should be considered to establish resonable measures.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6B
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• pp.363-371
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• 2012

In this study, the low-flow frequency analysis was performed to determine the low-flow standard of dam maintenance flow for Hwacheon and Chuncheon dams. For this purpose, two methods (case 1: low-flow frequency analysis using the monthly inflow data of the specified return periods, case 2: low-flow frequency analysis using the difference of monthly accumulated inflow) were applied. As a result, it is found that the monthly inflow data of the return periods by reflecting the statistical characteristics of Hwacheon and Chuncheon dams can be utilized to determine the standard of maintenance flow or water level.

• Journal of Korea Water Resources Association
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• v.42 no.12
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• pp.1069-1077
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• 2009

Lately, it is an important concern in water resources research to maintain a stable water supply according to a future climate change and an increase in water use. In Han-River basin, approximately 10 % of water resources that is provided the capital region (Gyeonggi, Seoul etc.) has been reduced as a consequence of the construction of Imnam Dam (storage volume: 27 billion $m^3$) located in the upper Hwacheon Dam upstream area. Therefore, streamflows have decreased in Bukhangang basin, but it could not be evaluated quantitatively. In this study, SWAT-K which is the physically based long-term runoff simulation model, was used in order to evaluate the effect of Imnam Dam on the reduced inflow to Hwacheon Dam according to the change of hydrological condition in the upstream area of Hwacheon Dam. For the model input data of North Korea area, meteorological data of GTS (Global Telecommunication System) were used, and soil maps by FAO/UNESCO (2003) were applied. Temporal variations of water resources is investigated with comparison of observed and simulated inflows at Hawcheon Dam site. Also, annual, monthly, seasonal decreases in water resources were evaluated using the flow duration analysis of simulated streamflows with or without Imnam dam.

• Journal of Korea Water Resources Association
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• v.53 no.1
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• pp.71-82
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• 2020

The objective of this study is to evaluate the instream flow in the North Han River basin according to the operation of Imnam Dam in North Korea. The water budget and instream flow satisfaction were analyzed using hourly, daily and monthly data of Water Management Information System (WAMIS) from Jan. 1991 to Dec. 2018. As a analysis result of water budget using hourly data in the North Han River basin, although inflows compared with dam release in the upstream basin of Peace Dam-Hwacheon Dam and Chuncheon Dam-Soyanggang Dam-Uiam Dam were calculated as negative values, the reasonable results using daily and monthly average data were estimated. It showed that the results of water budget analysis of dam inflow and total release may be different by time units of data. The monthly average inflow of Hwacheon Dam decreased significantly after the construction in 2003 of Imnam Dam, which confirmed that the operation of Imnam Dam had a significant effect on the dams in the North Han River basin. The operation of Imnam Dam is one of the main reasons for the lack of instream flow and total shortage amounts and shortage period increased up to +330% due to the decrease in inflow and total release of dams in the North Han River water after the operation of Imnam Dam. It is necessary to study various plans to secure instream flow including transboundary river management

• Journal of Korean Society on Water Environment
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• v.36 no.2
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• pp.89-97
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• 2020

North Han River is a very unique type of water system, where Hwacheon, Chuncheon, Soyanggang, Euiam and Cheongpyeong Dams are located consecutively. These dams are operated differently in the amount of discharge and release schedule according to their structure and purpose of use. They have different water quality characteristics depending on external pollutant inflow and internal mixing condition. Therefore, this study investigated the relationship between the upper dam and down stream river with respect to water quality indicators, such as water temperature, electrical conductivity, BOD, COD, TN and TP of the North Han River. The similarities and correlations representing the relationship were analyzed by Pearson's correlation r and t-test. The data was taken from the Ministry of Environment's water quality monitoring from 1999 to 2018. The results show that water temperature and electrical conductivity of the dam and river are similar and correlated. However, it turned out that there was no similarities and correlations in BOD, COD, TN and TP that are significantly affected by subaqueous reaction mechanism. The results of this study present the impact of the dam on the water quality of North Han River, which can be used as useful data for management of water quality.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.276-276
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• 2020

공유하천유역에서의 수자원 관리는 두 국가의 제도적 및 기술적 차이로 인하여 다른 유역에서의 수자원 관리보다 복잡하고 어렵다. 특히 두 국가 사이의 공유하천에서의 유량의 변화는 실질적인 측정을 이용하여 면밀하게 측정됨으로써 신뢰도 높은 자료를 통해 지속적으로 분석되어야 궁극적으로 공유하천에 대한 두 국가 간의 이해관계를 바탕으로 한 대책을 수립할 수 있다. 북한강 유역의 상류유역은 북한에 속해 있고, 특히 임남댐 건설 이후 화천댐 유입량은 지속적으로 감소하고 있어 이에 대한 물순환 영향을 면밀히 분석하고 대책을 수립할 필요가 있다. 물순환에 영향을 미치는 원인과 결과를 분석하는 기존의 연구들은 대부분 강우-유출모형을 사용하고 있어 모형의 구축 및 매개변수의 보정과 검증에 많은 노력이 필요하다. 본 연구에서는 수문기상자료만을 이용하여 유량의 변동성분을 정량화할 수 있는 수문학적 민감도 분석기법을 화천댐 상류유역에 적용하고 화천댐 유입량에 대한 1967년~017년 동안의 변동량을 자연적 요인과 인위적 요인으로 분리하여 제시하였다. 다양한 변동점 탐색기법을 사용한 결과 1999년이 통계적으로 유의한 변동점으로 탐색되었으며, 이를 활용하여 수문학적 민감도 분석을 5가지의 Budyko 함수를 이용하여 산정한 결과 평균적으로 18.99 억 ㎥/y의 유입량 감소가 임남댐 건설로 인하여 발생된 것을 알 수 있었다. 이와 같은 결과는 기존 연구자들의 화천댐 유입량 감소량에 비해 다소 크게 산정된 결과이며, 이는 2000년대 이후 증가된 강우량 및 화천댐유입량의 감소가 주된 영향을 미친 결과로 추정된다. 향후 월별, 계절별 단위의 분석이 추가로 연구될 필요가 있으며, 미래의 기후변화 상황을 고려한 예측을 통한 실효성 있는 계획이 수립될 필요가 있을 것으로 판단된다.