• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.550-555
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• 1999

yongdam multipurpose is under construction to divert a part fo Geum riverlfow to Mankyung watershed and to supply the domestic water to the Chunju region and produce the hydro-electricity. Generally construction of dam by the method of inther-region water transfer affects the quantity and quality of water inthe down streams and reservoirs. The impact of operation plan of Yondgam dam on the quantity and quality of water in the Guem river and Daechung dam was investigated .It was recommended that the discharge of water transfer from one watershed to another should be minimized as much as possible.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.5
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• pp.705-712
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• 2012

Selecting Daechung Dam as a sample study site, this study simulates virtual water quality incident which can be occurred using EFDC maintained by USEPA. In order to predict the behavior and diffusion of leaked conservative pollutant within dam under the worst condition, the hydrological data and information from 2008 were used. EFDC was successfully calibrated for observed water level obtained from the above sources. From the results of simulations, even though the concentrations (500 ppm, 1,000 ppm and 10,000 ppm) of leaked pollutant were different with each other at the same sources, the travel time of each peak concentration appeared similar. Also, changing the leak source point from dam gate(0 km) to 7 km, it was found that as leak source point was nearer to the dam gate, the travel time of each peak concentration showed up sooner. It was simulated to take 1 day to 15 days for initial appearance of the leaked pollutant according to the leaked points, and 3 days to 25 days for the reach of the peak concentration, respectively.

• Journal of Korea Water Resources Association
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• v.35 no.6
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• pp.737-751
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• 2002

Water quality in Daechung Lake was predicted for various discharge conditions of Yongdam dam. The same scenarios were applied as in the previous paper by the authors for Keum River water quality modeling. Effects in water quality due to changes in discharge conditions from Yongdam Dam were less distinct to the Daechung Lake than to the inflowing Keum River due to sink processes in the lake. For the minimum flow year, it is appropriate to maintain Yongdam dam discharge rate to 8.9 $m^3$/sec considering the current field conditions and future predictions of TN and TP concentrations of Yongdam dam. Effect of Yongdam dam discharge conditions to the Daechung Lake water quality were stronger for drier years. However it should be noted that the effects were dependent upon the water quality of Yongdam discharge at the same time. Therefore, water quality management effort should be emphasized before the discussion over the discharge volume of Yongdam dam. The input data sets for simulations in this study were formulated using the available data and assumptions based on authors experiences for the fields. Therefore, continued data collection effort will ensure the validity of this study.

• Journal of Korea Water Resources Association
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• v.34 no.5
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• pp.511-519
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• 2001

Global warming has begun since the industrial revolution and it is getting worse recently. Even though the increase of greenhouse gases such as $CO_2$is thought to be the main cause for glogal warming, its impact on global climate has not been revealed clearly in rather quantitative manners. The objective of this research is to predict the hydrological environment changes in the Daechung Dam basin due to the global warming. A mesoscale atmospheric/hydrologic model (IRSHAM96 model) is used to predict the possible changes in precipitation and temperature in the Daechun Dam basin. The simulation results of IRSHAM96 model and a conceptual water balance model are used to analyze the changes in soil moisture, evapotranspiration and runoff in the Daechung Dam basin. From the simulation results using the water balance model for 1x$CO_2$and 2x$CO_2$situations, it has been found that the runoff would be decreased in dry season, but increased in wet season due to the global warming. Therefore, it is predicted that the frequency of drought and flood occurrences in the Daechung Dam basin would be increased in 2x$CO_2$condition.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.499-502
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• 2003

Using the daily water balance model of the Keum River Barrage Dam, water supply capacity was analyzed. The scenario of reservoir inflow was selected to case with Daechung dam, case with no dam, case with Yongdam dams. Runoffs in 12 sub watersheds were simulated by the DAWAST model considered return flows.

• Journal of Korea Water Resources Association
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• v.35 no.5
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• pp.525-539
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• 2002

Effects of Yongdam Dam discharge conditions on water quality of the Keum River and Daechung Lake inflow were analyzed for various scenarios using WASP5 water quality model. Three different groups of scenarios were tested: 1) Two different weather conditions; the lowest flow year and the highest flow year since the beginning of Daechung Dam operation in 1981, 2) Fine discharge flow rates; 5.4, 8.9, 12.4, 16.4 ㎥/s and field observed flow during the study period, 3) Three conditions of discharge water quality; first grade, second grade by Korean water quality standard and field observed water quality. Effect of changes in Yongdam Dam discharges was greater for dry year. The increase of discharge from the Yongdam Dam will improve water quality of downstream areas only when the water quality of the discharge is equal or better than that of downstream areas. Field observed water qualify data show that BOD concentrations are lower than first grade level but TN and TP concentrations are exceeding 5th and 3rd grade level in Korean standard, respectively. Considering that nutrient control methods in watershed areas of Yongdam dam are limited, it is expected that nutrient concentrations from Yongdam Dam discharge will be higher than 2nd grade water quality standard level. Therefore, it would be important to develop practical management strategies in the watershed area of Yongdam Dam based on field conditions for conservation of water quality in downstream areas.

• Proceedings of the Korea Water Resources Association Conference
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• 2001.05a
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• pp.501-506
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• 2001

• Journal of Korea Water Resources Association
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• v.37 no.4
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• pp.273-281
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• 2004

Generally, reservoir storage is allocated according to planned purposes established before construction and operating policies are established through release control. The established reservoir allocation is hardly changed unless the special cases such as raising dam or changed purposes occur It Is, however, likely that public needs and objectives can be changed as time go on, the study for multipurpose reservoir storage reallocation is performed as an alternative to reflect these. In this study, flood control analysis is performed for several alternatives of reallocation for the Daechung multi-purpose reservoir in Geum river. As a result, it is confirmed that flood control capability is not decreased compared to single operation of Daechung reservoir for the same flood condition even if conservation level of Daechung multi-purpose reservoir is increased.

• Journal of Korea Water Resources Association
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• v.34 no.4
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• pp.335-345
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• 2001

The objective of this research is to analyze the hydrological environment changes in Daechung Dam Basin due to the global warming. GCM simulation results are used to predict the possible changes in precipitation and temperature. The changes of potential evapotranspiration, soil moisture and runoff due to the changes of precipitation and temperature are analyzed using a conceptual water balance model. From the simulation results using the water balance model for lx$CO_2$ and 2x$CO_2$ situations, it has been found that the runoff would decrease in Winter, but increase in Summer and Fall due to the global warming. Therefore, it is predicted that the frequency of drought and flood occurrences in Daechung Dam Basin would be increased in 2x$CO_2$ condition.

• The Korean Journal of Mycology
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• v.48 no.3
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• pp.237-249
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• 2020

The goal of this study was to isolate wild yeasts from waters and soils in Sangjubo of Nakdong river and Daechung dam in Daejeon city, Korea and investigate characteristics of previously unrecorded novel wild yeasts. In total, 94 strains from 39 different species of wild yeasts were isolated from 47 soils and waters samples obtained from Sangjubo in Nakdong river. Among these, 3 strains, including Rhodosporidium azoricum JSL-GRU-009, represented novel yeast strains which were previous recorded. Two hundred nine strains from 105 different species of wild yeasts were isolated from 130 soils and water samples obtained from Daechungdaegyo and Daechung dam of Shintanjin in Daejeon city, Korea. Ten strains including Bullera pseudoalba JSL-GRU-005 also represented newly recorded strains in Korea. All the 13 previously unrecorded yeasts were oval or global in shape, and nine strains, including R. azoricum JSL-GRU-009, formed ascospores. Ten strains grew well in vitamin-free medium. R. azoricum JSL-GRU-009 grew well in 20% glucose-containing yeast extract-peptone-dextrose (YPD) medium and 3 strains, including Rhodotorula oryzicola JSL-GRU-003, grew well in 5% NaCl-containing YPD medium.