• Korean Journal of Agricultural Science
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• 제38권3호
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• pp.513-524
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• 2011

To evaluate the applicability of inflow runoff model to reservoir operation in Korea, DAWAST model and TPHM model which are conceptual lumped daily runoff model and were developed in Korea, were selected and applied to simulate inflows to Daecheong multipurpose dam with watershed area of 4,134 $km^2$, and water storages in Geryong reservoir with watershed area of 15.1 $km^2$ and total water storage of 3.4 M $m^3$. Evaluating inflows on an yearly, monthly, ten-day, and daily basis, inflows by DAWAST model showed balanced scatters around equal value line. But inflow by TPHM model showed high in high flows. Annual mean water balance by DAWAST model was rainfall of 1,159.9 mm, evapotranspiration of 622.1 mm, and inflow of 644.6 mm, from which rainfall was 104.8 mm less than sum of evapotranspiration and inflow, and showed unbalanced result. Water balance by TPHM model showed satisfactory result. Reservoir water storages were shown to simulate on a considerable level from applying DAWAST and TPHM models to simulate inflows to Geryong reservoir. But it was concluded to be needed to improve DAWAST and TPHM model together from imbalance of water balance and low estimation in high flow.

• Journal of Environmental Health Sciences
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• 제44권6호
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• pp.581-590
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• 2018

Objectives: We aimed to investigate the species composition of fish and benthic macroinvertebrates in the Namgang Dam reservoir and assess the reservoir's ecological quality. Methods: Fish and benthic macroinvertebrates were seasonally sampled around the Namgang Dam reservoir from October 2013 to September 2014. Results: A total of 970 fish specimens were collected for this survey, including 4 orders, 14 families, and 25 species. Fourteen endemic species were observed, including Coreoleuciscus splendidus. The most observed among the endemic species caught was Zacco koreanus (14.4%). A total of 9,093 benthic macroinvertebrates, including 51 families and 92 species, were also found. The predominant species in the study area was Chironomidae sp. 1. Diplonychus esakii, whose habitat is distribution-specific as designated by the Korean National Institute of Environmental Research (NIER), were also observed. A total of 386 specimens were collected of the invasive alien species Lepomis macrochirus, and the percentage of Lepomis macrochirus and Micropterus salmoides made up 42.0% of all specimens collected in the area. Conclusion: The mean ecological score of the benthic macroinvertebrate community (ESB) ranged between 24 and 40, which indicates that the environmental condition of the target sites is somewhat poor. Based on the results of this research, building habitats for benthic macroinvertebrates should be considered, and extermination plans for invasive alien fish species should be prepared.

• Magazine of the Korean Society of Agricultural Engineers
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• 제37권E호
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• pp.47-54
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• 1995

Irrigation water has been mainly used for paddy rice. Irrigated paddy land tends to be recently converted to land for green house, farm house, and rural-industrial complex. Consequently, demand of water for crops, domestic & industrial, rural recreations, small-scaled hydropower, livestocks, and environment in the rural area, so called rural water, is rapidly increasing. In order to supply rural water, water in the existing irrigation reservoir could be enlarged by repairment of irrigation canal and reinforcement of irrigation reservoir, and be saved by the operation rule curve, utilization of dead water, and balanced storage management.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.202-206
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• 2001

In this study, the risk assessment of small reservoir by collapse using GIS is evaluated. Direct damage distance from collapsed reservoir is estimated by empirical USBR equations and submerged area is calculated by USBR's idea. The amount of damage by collapsed reservoir is figured out by damage assessment of National Institute for Disaster Prevention.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.657-662
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• 1999

This study was conducted for the purpose of assessing the pollutant removal possibilities of sedimentation pool formed by deep dredging of a reservir inlet. Water quality data were collected in the Masan reservoir, whose inlet has been dredged deep like sedimentation pool. The average concentration of chemical oxygen demand(COD), total nitrogen(T-N) adnd total phosphorous(T-P) in the deep dredged area were 8.3∼28.4mg/$\ell$ (COD), 2.0∼6.0mg/$\ell$(T-N), 0.17∼1.34mg/$\ell$(T-P), which were 3.3% (COD) , 30.6%(T-N) and 46.4%(T-P) higher than those of middle part of the reservoir. From these results, it was considered the deep dredged area in the inlet of reservoir might play a key role to improve reservoir water quality.

• Environmental Engineering Research
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• 제13권1호
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• pp.33-40
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• 2008

Levels of arsenic in stream and reservoir waters affected by an abandoned gold mine were examined. The abandoned mine has been left without proper civil and remedial works preventing potential environmental hazards. Field and laboratory chemical analyses revealed that the stream waters downgradient from the mine area were severely contaminated with arsenic and furthermore the reservoir water, 2-3 km away from the mine, also contained substantial levels of As, far exceeding the Korean stream water standard. Relatively higher pH values (6.5-9.4) enhanced mobility of As and mainly sustained substantial As concentration in waters. Chemistries of the stream water, groundwater and reservoir water were dominated by two main factors including effects of mine effluent and anthropogenic agricultural activities. Considering that there has been a substantial As input to the reservoir and the reservoir water has been used for agricultural and domestic uses, immediate remedial works are essentially required.

• Journal of Korea Water Resources Association
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• 제51권1호
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• pp.61-70
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• 2018

This study examined how to determine the optimal sediment level in dam reservoir for efficient plan and operation of dam. Currently, Korea is applying a horizontally accumulated method for sediment level estimation for the safety design of dam and so the method estimated relatively higher level than others. However, the sediment level of dam reservoir should be accurately estimated because it is an important factor in assessing life cycle of a dam. The sediment level in dam reservoir can be determined by SED-2D model linked with RMA-2, horizontally accumulated method, area increment method, and empirical area reduction method. The estimated sediment level from each method was compared with the observed sediment level measured in 2007 in Imha dam reservoir, Korea and then the optimal method was determined. Also, the future sediment level was predicted by each method for the future trend analysis of sediment level. As the results, the most accurate sediment level was estimated by the empirical area reduction method and the future trend of sediment level variation followed the past trend. Therefore, we have found that the empirical area reduction method is a proper one for more accurate estimation of sediment level and it can be validated by the results from a numerical model of SED-2D linked with RMA-2 model.

• Journal of Wetlands Research
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• 제25권1호
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• pp.14-25
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• 2023

Floodplain in a reservoir is defined as the area naturally formed between the design flood level and the normal pool level. Located around the dam reservoir, floodplain has been damaged in many different ways including cultivation. As it is impossible to restore all the damaged floodplain at once, it is necessary to determine their order of priority. This process considers various factors, among which the flooding frequency is an important hydrologic characteristic, Different from the floodplains in a river, all the floodplains around the given dam reservoir have the same flooding frequency. To overcome this problem, this study proposes to use the cumulative flooding area curve, which represents the cumulative flooding area corresponding to the reservoir water level. Especially, this study evaluates the flooding frequency of those water levels corresponding to the cumulative flooding area of 30%, 50% and 70%. As application examples, this study considers the five restoration candidates each selected in the Andong Dam, Imha Dam, Youngju Dam and Nam river Dam of the Nakdong River Basin. As a result, the cumulative flooding area curve was found to well represent the overall shape of the floodplain (i.e., steep-to-mild slope or mild-to-steep slope). Also, the flooding frequency of those water levels corresponding to the cumulative flooding area of 30%, 50% and 70% was found to be so effective to quantify the hydrologic characteristics of a floodplain.

• Journal of The Korean Society of Agricultural Engineers
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• 제53권6호
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• pp.7-16
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• 2011

This study discussed the applicability of satellite SAR (Synthetic Aperture Radar) imagery with regard to reservoir monitoring, and tried the extraction of reservoir storage from multi-temporal C-band RADARSAT-1 SAR backscattering images of Yedang and Goongpyeong agricultural reservoirs, acquired from May to October 2005. SAR technology has been advanced as a complementary and alternative approach to optical remote sensing and in-situ measurement. Water bodies in SAR imagery represent low brightness induced by low backscattering, and reservoir storage can be derived from the backscatter contrast with the level-area-volume relationship of each reservoir. The threshold segmentation over the routine preprocessing of SAR images such as speckle reduction and low-pass filtering concluded a significant correlation between the SAR-derived reservoir storage and the observation record in spite of the considerable disagreement. The result showed up critical limitations for adopting SAR data to reservoir monitoring as follows: the inappropriate specifications of SAR data, the unreliable rating curve of reservoir, the lack of climatic information such as wind and precipitation, the interruption of inside and neighboring land cover, and so on. Furthermore, better accuracy of SAR-based reservoir monitoring could be expected through different alternatives such as multi-sensor image fusion, water level measurement with altimeters or interferometry, etc.

• Journal of Environmental Science International
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• 제12권4호
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• pp.439-446
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• 2003

In this paper, the study area is selected Sungju Reservoir which was constructed with an agricultural purpose and determined the optimal water management plan among the five cases of classified irrigation area by using Linear Programming. As a results of reservoir operation, the additional water quantity of classified irrigation area showed 16.036${\times}$10$\^$6/m$^3$3/year, 19.404${\times}$10$\^$6/m$^3$/year, 18.864${\times}$100$\^$6/m$^3$/year, 4.032${\times}$10$\^$6/m$^3$/year and 0.672${\times}$10$\^$6/m$^3$/year and the total water supply quantity showed 69.628${\times}$10$\^$6/m$^3$/year, 70.048${\times}$10$\^$6/m$^3$/year, 67.979${\times}$10$\^$ 6/m$^3$/year, 67.979${\times}$10$\^$6/m$^3$/year, and 69.939${\times}$10$\^$6/m$^3$/year respectively. Therefore, the case-II was adopted with water management plan of optimum. It is also known that the maximum irrigation area augmentation effect appears in the case which will use the additional water quantity in field irrigation of the case-II which was adopted.