• 한국농공학회지
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• 제33권4호
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• pp.52-60
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• 1991

This study was conducted to investigate the appropriate operation method minimizing the deviation between irrigation water demand and release from the reservoirs, and the simulation technique was used in the operation model. This model was applied to the grouped reservoirs system consisted of Dongsang, Daia and Keungchun reservoirs and Eowoo-weir in Chonbuk FLIA district. The results obtained in this study are summarized as follows; 1.The area above the Eowoo weir point was divided into 6 small watersheds, and daily inflows from each watershed were calculated by Tank model. It showed that the average annual runoff ratio was 40-60% respectively. 2.Based on the Blaney-Criddle formula daily water requirement of Chonbuk FLIA irrigation area was estimated, mean water requirement for paddy field during the irrigation period was 818.lmm. 3.Using the basic data such as inflow and water demand, four different release types were selected. Through the simulated operation the difference between intake water required at Eowoo-weir point and release from the 3 reservoirs was estimated. The best result was obtained when Daia and Keungchun reservoirs are operated parallelly at fixed release ratio and the release of Dongsang reservoir was determined according to the storage of Daia reservoir.

• 한국농공학회지
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• 제44권3호
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• pp.136-145
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• 2002

Monitoring data from agricultural reservoirs throughout the country were analyzed to evaluate the limiting factor fur algal growth and relationships between Chl-a, total phosphorus (TP), and total nitrogen (TN). Total 394 reservoirs ranging from below 500 ㎥ to over 50 million ㎥ in storage volume were monitored from 1990 to 2000 with respect to TP, W, Chl-a, and their annual mean values were used fur the analysis. Based on N/P ratio, the dominant limiting factor for algal growth was turned out to be phosphorus in agricultural reservoirs (about 83%). Therefore, the proper managements of phosphorus in the agricultural watershed appear to be crucial to prevent excessive on algal growth. The effects of phosphorus and nitrogen ware most eminent during the summer period. And the effect of nutrients on the algal biomass (Chl-a) development appeared to be greater in smaller the reservoirs than in larger ones. Generally, Chl-a and TP demonstrated a close relationship while that of Chl-a and TN showed less correlationship. Chl-a and chemical oxygen demand (COD) also showed a good relationship. Beth ratios of Chl-a / TP and Chl-a / COD relationships were within the range of literature values. Quantitative analysis of TP and COD is relatively convenient compared to that of Chl-a, and the relationship between TP and COD and Chl-a from this study could be used beneficially for water quality management of agricultural reservoirs and related water quality modeling.

• 한국농공학회논문집
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• 제59권3호
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• pp.11-19
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• 2017

The decision-making process is the act of finding the best solution among various alternatives through comparison between various criteria based on objectives of the project, evaluation standard, and conditions. However, in practice it is not easy to simply decide the optimum decision, especially for selecting malfunctioning reservoirs because no systematic evaluation criteria or standard assessment process are available. Therefore, this study adopted AHP method, which is a MCDM (multi-criteria decision making technique) to identify the malfunctioning reservoirs for efficient management of reservoirs. Important criteria of the selection of malfunctioning reservoirs and priority weights of each criteria were determined based on results of expert's survey under a stepwise hierarchical approach. The most important factor for the decision of malfunctioning reservoirs was obtained as Reservoir efficiency among the selected criteria including Reservoir efficiency decrease, Disaster Risk, Reservoir efficiency, Available water storage, Future water demand, Resident Needs. The AHP technique was applied on 11 reservoirs in Andong region to verify its applicability. Scoring method was applied for the comparison with the results of AHP method.

• 생태와환경
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• 제41권spc호
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• pp.1-10
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• 2008

We patterned water quality of agricultural reservoirs according to the differences of six physico-chemical environmental factors (TN, TP, DO, BOD, COD, and SS) using four different ordination methods: Principal Components Analysis (PCA), Detrended Correspondence Analysis (DCA), Nonmetric Multidimensional Scaling (NMS), and Isometric Feature Mapping (Isomap). The data set was obtained from the water quality monitoring networks operated by the Ministry of Agriculture and Forestry and the Ministry of Environments. Chlorophyll-${\alpha}$ displayed the highest correlation with COD, followed by TP, BOD, SS, and TN (p<0.01), while negatively correlated with altitude and bank height of the reservoirs (p<0.01). Although four different ordination methods similarly patterned the reservoirs according to the gradient of nutrient concentration, PCA and NMS appeared to be the most efficient methods to pattern water quality of reservoirs based on the explanation power. Considering variable scores in the ordination map, the concentration of nutrients was positively correlated with Chl-${\alpha}$, while negatively correlated with altitude and bank height. These ordination methods may help to pattern agricultural reservoirs according to their water quality characteristics.

• 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.

• 농업과학연구
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• 제38권2호
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• pp.331-341
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• 2011

To provide variation of water supply for instream flow from reservoirs with various magnifications of paddy irrigation area to watershed area, 8 reservoirs were selected to draw operation rule curve and to analyze water supplies from reservoirs. Reliability of 90% for supplying irrigation water from reservoir was able to maintain and instream flow water was able to be supplied only in the reservoir with magnification of paddy irrigation area to watershed area above 3. The more magnification of paddy irrigation area to watershed area increased, the more ratio of irrigation water to total water storage decreased, and the more ratio of instream flow water to total water storage increased. From the heightening 113 reservoirs in Korea, annual irrigation water was estimated to 1,146.05 $Mm^3$ in normal operation, 839.57 $Mm^3$ in withdrawal limited operation, and annual instream flow water was estimated to 149.68 $Mm^3$ in normal operation, 283.19 $Mm^3$ in withdrawal limited operation. It was concluded that withdrawal limited operation was followed to have the premise of saving irrigation water, more instream flow water was able to be supplied from reservoirs with high magnification of paddy irrigation area to watershed area.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2009년도 특별 심포지엄
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• pp.35-45
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• 2009

Reservoir Characterization (RC) using 3-D seismic attributes analysis can provide properties of the oil sand reservoirs, beyond seismic resolution. For example, distributions and temporal bed thicknesses of reservoirs could be characterized by Spectral Decomposition (SD) and additional seismic attributes such as wavelet classification. To extract physical properties of the reservoirs, we applied 3-D seismic attributes analysis to the oil sand reservoirs in McMurray formation, in BlackGold Oilsands Lease, Alberta Canada. Because of high viscosity of the bitumen, Enhanced Oil Recovery (EOR) technology will be necessarily applied to produce the bitumen in a steam chamber generated by Steam Assisted Gravity Drainage (SAGD). To optimize the application of SAGD, it is critical to identify the distributions and thicknesses of the channel sand reservoirs and shale barriers in the promising areas. By 3-D seismic attributes analysis, we could understand the expected paleo-channel and characteristics of the reservoirs. However, further seismic analysis (e.g., elastic impedance inversion and AVO inversion) as well as geological interpretations are still required to improve the resolution and quality of RC.

• 생태와환경
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• 제40권2호
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• pp.214-222
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• 2007

본 연구에서는 국내 분포하고 있는 490개 저수지를 대상으로 유역특성과 수질과의 관계를 조사하였고, TSI편차분석을 통해 유형을 구분하여 영양염 측면에서의 각 유형별 특성을 조사하였다. 본 연구 대상저수지에서 수심이 얕을수록 부영양화 가능성이 높게 나타났다. 유역 내 논과 밭의 이용면적이 30%이상인 경우 수체 내 TP농도는 평균 0.1 mg $L^{-1}$ 이상이었다. TN 농도는 유역전체면적 중 논의 면적이 25% 이상인 경우에 평균 2.6 mg $L^{-1}$이상의 분포를 나타냈다. TSI편차를 통해 구분된 형태 중 TYPE III에 해당하는 저수지의 수질항목별 평균 농도는 다른 두 형태에 포함된 저수지에서 보다 2배 이상 높은 수준이었다. TYPE III에 포함된 저수지는 다른 두 유형에 포함된 저수지와 비교해 부영양상태이고, 수심이 얕으며, 수표면적에 대한 유역면적비 (DA/RA)가 작고, 논과 밭으로의 이용면적이 넓었다. TYPE I과 II에 포함된 저수지의 수질은 TYPE II에서 BOD와 엽록소 ${\alpha}$농도가 높은 것을 제외하고는 유사한 수준이었고, 형태학적 특성(평균수심, DA/RA)이나 토지이용형태 또한 유사하였다. TYPE I에 포함된 저수지들에서는 인이 조류성장에 대한 일차적인 제한요인은 아닌 것으로 나타났다. 본 연구에서 모든 대상저수지에서 인의 제한가능성이 나타났으며, 토지이용형태, 특히 유역 내 논과 밭으로의 이용면적은 저수지의 수질을 결정하는 매우 중요한 인자였다.

• 한국물환경학회지
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• 제21권1호
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• pp.52-58
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• 2005

The assessment on characteristics of hydraulic behavior and water quality variations of underground reservoirs of buildings were studied. Firstly, it was thought that underground reservoir capacities($m^3$) of buildings should be not determinated by the uniform and same methods but be estimated on the basis of the dwelling areas on dominated households and their residential characteristics, because these characteristics influence significantly on actual water usages and patterns of buildings. Secondly, it was likely that the average reduction rate of residual chlorine in underground reservoirs were affected from the their capacities, because the average reduction rate of residual chlorine in underground reservoirs under $1,000m^3$ was 43 percent, on the other hand, that rate of underground reservoirs over $1,000m^3$ was 60 percent. Thirdly, through the field investigation, the retention time of drinking water in underground reservoirs were in the range from 0.3 day to 3.9 day. In addition to, the average reduction rate of residual chlorine were depended largely on the retention time of drinking water. When the retention time was under 24 hours, the average reduction rate of residual chlorine was 45 percent, and in case of over 24 hours, was 49 percent. Fourth, water level in underground reservoirs was averagely varied in the range from 0.1 m to 2.65 m at the height of underground reservoirs. If considered actual height of underground reservoirs, 37.6 percent of the height of underground reservoirs was only used. Consequently, the frequency of the inflow and outflow of drinking water in underground reservoir were very increased, and had an effect on the reduction of residual chlorine. Lastly, the investigations on hydraulic structure characteristics of underground reservoirs inside showed the locations of inflow and outflow of drinking water almost were in the opposite direction. And some buildings had several baffles in the middle. Nevertheless, their installations had no beneficial for the improvement of water quality.

• 한국농촌건축학회논문집
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• 제22권3호
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• pp.17-24
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• 2020

Reservoirs, which make up most of South Korea's reservoirs, are located in rural areas. In the case of rural reservoirs, about 75% have been reported over 50 years old aged reservoirs constructed before the 1960s. Reservoirs are important facilities that store and supply water necessary for daily life. However, if it is destroyed, the reservoir can cause a lot of damage, so continuous management is necessary. As a method for strengthening old reservoirs, a method using cement has been widely applied. However, OPC is a product that uses a lot of carbon dioxide and natural resources. Therefore, the amount of cement should be reduced. Against this background, in this study, the ground injection material of utilizing circulation resources was applied to the site. Applied reservoirs have been around for 75 years and leaks have occurred in some sections. The application method was constructed in two rows, up to a depth of 12m. After reinforcement, the electrical resistivity test was conducted three times. As a result, similar resistance was shown at 1 month after construction. And after 6 months, the saturation area decreased. And the performance after reinforcing the aged reservoir was examined. As a result of the review, this study confirmed that the applicability was equivalent to that of OPC, and the excellent performance of reinforcing the aged reservoir was shown.