• 한국농공학회:학술대회논문집
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• 한국농공학회 1998년도 학술발표회 발표논문집
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• pp.279-286
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• 1998

The south-western part of Korea is situated in an unbalance of water supply and demand relating to the Keum, Mankyung, Dongjin and Youngsan River and their estuary reservoirs. For example, the Keum River estuary reservoir is discharging the larger amount of yearly runoff into the sea due to the small storage capacity, while Saemankeum estuary reservoir which is under construction, has the smaller runoff amount comparing with its storage capacity, And the downstream area of the Youngsan River, such as Youngkwang, Youngam are deficient in water due in larger demand and smaller supply. In order to solve the above unbalanced water supply and demand and also to improve the water use efficiency, the Hierarchical Operation Model for Multi-reservoir System(HOMMS) has been developed and applied to analyze the multi-reservoir operation assuming that the above reservoirs were linked each other. The result of this study shows that 2,148MCM of annual additional water requirement for agricultural and rural water demands are required in this region at 2011 of target year, and these demands can be resolved by diverting and reusing 1,913MCM of the released water from the estuary reservoirs into the sea.

• 한국농공학회논문집
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• 제54권5호
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• pp.17-24
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• 2012

The main purposes of the agricultural reservoir enlargement (ARE) project are to secure water supply reliability (WSR) for agriculture and to release environmental water during dry seasons. In this study, an operational rule that will simultaneously satisfy both the above issues was developed. Initial amount of water storage at the beginning of non-irrigation season (1st October) was divided into 3 stages, and the target level of water storage at the beginning of irrigation seasons (1st April) was set up. Required operational curves and release amounts were estimated based on the stages and target water levels. To evaluate the applicability of this rule, the amount of water released for environmental purposes and WSRs were analyzed for three reservoirs (Unam, Jangchi and Topjeong). The ratio between annual amount of release and additional amount of water storage were 1.6, 1.85, and 4.1 for the Unam, Jangchi, Tapjeong reservoirs, respectively. Also, the WSRs of all reservoirs were found to become higher than when the design standard was applied. Therefore, it is considered that the proposed rule is more suitable for the enlarged agricultural reservoirs operation as it satisfies the WSRs while securing the environmental water release.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.515-515
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• 2022

Climate change is strongly threatening the performance of agricultural reservoirs, which are instrumental in ensuring uninterrupted water supplies for rice cultivation in Korea. In this study, various performance indices were derived and overall sustainability of the 400 agricultural reservoirs was evaluated in the context of climate change trends during 1973-2017. Rice crop evapotranspiration, irrigation water requirements, runoff generation in the upstream watershed, and volumetric evaporation losses were plugged into a water balance model to simulate the reservoir operation during the study period. Resilience, reliability, and vulnerability are the three main indicators of reservoir performance, and these were combined into a single sustainability metric to define the overall system credibility. Historical climate data analysis confirmed that the country is facing a gradual warming shift, particularly in the central and southern agricultural regions. Although annual cumulative rainfall increased over the last 45 years, uneven monthly rainfall distribution during the dry and wet seasons also exacerbated the severity and frequency of droughts/floods. For approximately 85% of the selected reservoirs, the sustainability ranged between 0.35 to 0.77, and this range narrowed sharply with time, particularly for the reservoirs located in the western and southern coast regions. The study outcomes could help in developing the acceptable ranges of the performance indices and implementing appropriate policy and technical interventions for improving the sustainability of reservoirs with unacceptable ranges of the performance indices.

• 한국관개배수논문집
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• 제18권1호
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• pp.81-93
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• 2011

Agricultural reservoirs importantly role for paddy rice cultivation with about 18,000 numbers, so that understanding of operational rules for the reservoirs is quite meaningful for proper irrigation water supply. In this study, a survey was conducted to investigate a key reservoir operational elements over nationwide. The target reservoirs are mainly operated by KRC (Korea Rural Community Corporation) and 221 water management persons in province office of KRC were involved in this survey. The key reservoir operational elements including starting and ending time for irrigation, transplanting water supply periods, midsummer drainage periods and drought response strategy were surveyed. The results of this study demonstrated that the key elements for reservoir operation depend on weather, rice variety and cultivation conditions.

• 한국방재학회 논문집
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• 제10권1호
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• pp.89-102
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• 2010

미래의 기후조건과 생활패턴의 불확실성으로 인해 미래용수수요 또한 불확실성을 가지며, 이는 충분한 용수공급을 목적으로 하는 댐 운영에 어려움을 초래한다. 따라서 가용 수자원을 최대한 활용하여 충분한 용수분배를 하는 동시에, 홍수와 가뭄에 대한 대비까지 가능한 댐의 운영은 매우 중요하다. 본 연구에서는 미래의 불확실한 용수수요량을 정확히 알지 못하는 상태에서 저수지의 운영을 통한 저류량을 1단계에서 결정하고, 2단계에서 용수수요에 따른 용수공급량과 하천유지유량을 결정하기 위한 최적화 모형을 2단계 추계학적 선형계획법을 이용하여 구축하고, 목표저류량과 실제 저류량의 차이, 용수공급과 하천유지유량의 부족량을 최소화하기 위한 저수지 운영 규칙을 최적화하였다. 또한 가뭄시 보다 현실적이고 효율적인 저수지 운영을 위해 댐저류량에 따라 댐 계획방류량을 일정비율 줄여주는 Hedging Rule을 사용하여 모형의 적절성과 적용성을 향상시켰다. 제안된 모형은 한강수계의 댐들 중 다목적댐인 충주, 횡성, 소양강 댐과 용수전용댐인 광동 댐, 그리고 발전용 댐이지만 비교적 큰 저류용량을 가진 화천 댐을 연계 운영 대상으로 하여, 미래 용수수요량 시나리오를 고려한 최적화를 실시하였다. 그 결과 모든 시나리오에서 생공용수, 농업용수, 하천유지용수 공급량을 대부분 만족시킬 수 있었고, 댐의 저류량 역시 갈수기 용수공급에 대비하여 홍수기인 6월 말에서 9월 중순에 저류량을 확보하면서도 홍수피해저감까지 고려하는 운영이 가능하였다. 이는 다목적 댐들의 연계운영을 위한 저수지 운영규칙결정에 매우 중요한 지표가 될 수 있을 것으로 판단된다.

• 한국농공학회지
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• 제39권2호
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• pp.1-8
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• 1997

Abstract The need for integrated reservoir system operation become more intense as the demands from the system increase. A deterministic, three-dimensional discrete incremental dynamic programming approach is presented to derive reservoirs system operational planning strategies. The developed H3DP model optimizes the monthly operation of the Hwachon and Soyang Projects on the North Han river and Chungju Main Project on the South Han river. By using the H3DP model, Hwachon project was reevaluated as a component of the upstream multipurpose storage reservoirs in the basin based on 1993 hydrology. This case study demonstrates the practical use of the developed model for the basin multi-reservoir system operation in an integrated, multipurpose fashion.

• 한국농공학회논문집
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• 제63권1호
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• pp.27-35
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• 2021

KRC (Korea Rural Community Corporation) is in charge of about 3,400 agricultural reservoirs out of 17,240 agricultural reservoirs, and automatic water level gauges in reservoirs and canals were installed to collect reservoir and canal water level data from 2010. In this study, 10-minute water level data of 173 reservoir irrigation canals from 2016 to 2018 are collected, and discharge during irrigation season was calculated using rating curves. For estimation of water supply, irrigation water requirement was calculated with HOMWRS (Hydrological Operation Model for Water Resources System), and the summation of reservoir water storage decrease was calculated with daily reservoir storage data from RAWRIS (Rural Agricultural Water Resource Information System). From the results, the total yearly amount of irrigation water supply showed less than 10% difference than the irrigation water requirement. The regional analysis revealed that reservoirs in Jeollanam-do and Chungcheongnam-do supply greater irrigation water than average. On the contrary, reservoirs in Gyeongsangnam-do and Chungcheongbuk-do supply less than others. This study was conducted with a limited number of reservoirs compared to total agricultural reservoirs. Nevertheless, it can indicate irrigation water supply from agricultural reservoirs to provide information about agricultural water use for irrigation.

• Ecology and Resilient Infrastructure
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• 제6권2호
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• pp.79-88
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• 2019

우리나라 저수지의 수질 특성과 이에 영향을 미치는 환경요인을 파악하기 위하여, 운영목적, 수위변동 및 지리적 분포가 다양한 73개 저수지를 선정하여 수질 요인으로 화학적산소요구량 (COD), 엽록소 a (Chl a), 총인 (TP), 총질소 (TN)를, 수문지형 요인으로 연수위변동폭, 총저수량, 댐의 고도, 유역 면적, 호안발달도 (shoreline development index)를, 토지피복 요인으로서 산림, 농경지 및 도시화지역의 면적비율을 조사하였다. 저수지 수질은 유역의 도시화지역과 농업지역의 면적 비율이 크고, 고도가 낮고 연수위변동폭과 유역면적이 좁으며 총저수량이 적고 원형에 가까운 형태의 저수지에서 더욱 부영양화가 심하였다. 저수지 운영목적에서는 농업용수용 저수지가 홍수조절용 저수지보다 수질이 좋지 않았다. 변수선택과 경로분석의 결과에서, TP에 의한 Chl a에 영향을 받는 COD는 수위변동폭과 호안발달도에 의하여 직접적으로 영향을 받았다. 또한 TP는 유역의 도시화면적에 의하여 직접적으로 영향을 받으며 토지이용은 저수지의 고도와 관련이 있었다. 한편 TP는 수위변동폭과 호안발달도에 영향을 받았다. 결론적으로 우리나라의 저수지 부영양화는 유역의 토지이용, 수문적, 지형적 특성에 의하여 영향을 받으며, 특히 저수지 운영목적에 따른 인위적인 물관리에 의한 수위변동과 저수지의 위치에 의하여 수질 특징이 결정된다고 생각된다.

• 한국물환경학회지
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• 제30권1호
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• pp.31-43
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• 2014

Recently, Andong Reservoir and Imha Reservoir located in Nakdong River basin (Korea) are being connected by a tunnel (length 2km, diameter 5.5m) for a conjunctive use. The objectives of this study were to construct a two dimensional(2D) laterally-averaged model for two reservoirs, and examine the effects of connection on the water transportation and temperature stratification in the reservoirs. The 2D models for each reservoir were calibrated using field data obtained in 2006, and applied to the linked system for the year of 2002 when a severe flood intruded into Imha Reservoir during the typhoon Rusa. Simulation results showed that 364 million $m^3$ of water can be conveyed from Imha to Andong, while 291 million $m^3$ of water from Andong to Imha after connection. It resulted in 1.38 m increase of annual averaged water level in Andong Reservoir, whereas 3.75 m decrease in Imha Reservoir. The structures of thermal stratification in both reservoirs were influenced in line with the flow exchanges. In Andong Reservoir, the location of thermocline moved upward about 10 m compared to an independent operation. The results imply that the persistent turbidity issue of Imha Reservoir might be shifted to Andong Reservoir during a severe flood event after connection.

• 농업과학연구
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• 제49권4호
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• pp.707-717
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• 2022

As the variability of recent rainfall is increasing, it is becoming important to recognize the possibility of changes in the current reservoir state in advance and to inspect the stability based on accurate evaluation standards. However, the evaluation standards for the state change factors of reservoirs are still not suitable for agricultural reservoirs and thus much improvement is needed. Therefore, in this study, the evaluation criteria for state change factors specialized for small reservoirs were categorized and standards were prepared by considering factors that may cause state changes on the dam crest, upstream slope, and downstream slope of the embankment. The categorized results were configured based on the number of mentions of the precision safety inspection report on major defects in 102 reservoirs and the defect factors found in field investigations. The findings of the study indicated that the current state change standards require many revisions for excessive or unnecessary state change factors in the reservoir. Specifically, the deletion of measurement gauges not applicable to the reservoir, the addition of defects found in the reservoir, and the scope of use of the term were proposed. The results of this study can contribute to efficient system operation and management by improving the deficiencies in the system and introducing a new state change factor.