• Journal of Environmental Science International
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• v.19 no.10
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• pp.1211-1217
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• 2010

For an accurate rainfall-runoff simulation in the river basin, it is important to consider not only evaluation of runoff model but also accurate runoff component. In this study long-term runoffs were simulated by means of watershed runoff model and the amounts of runoff components such as upstream inflow, surface runoff, return flow and dam release were evaluated based on the concept of water budget. SSARR model was applied to Daecheong basin, the upstream region of Geum river basin, and in turn the monthly runoff discharges of main control points in the basin were analyzed. In addition, for the purpose of providing the basic quantified water resources data the conceptual runoff amounts were estimated with water budget analysis and the reliability of the observations and the monthly runoff characteristics were investigated in depth. The yearly runoff ratios were also estimated and compared with the observations. From the results of the main control points, Yongdam, Hotan, Okcheon and Daecheong, the yearly runoff ratios of those points are consistent well with data reported previously.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.932-936
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• 2007

In this study, it analyzed the hydrosphere change up to recently since the construction of Daecheong dam using Landsat satellite images and qualitatively the hydrosphere change of the Daecheong dam basin. These study detected the hydrosphere change with applying supervised classification about Landsat satellite image corresponding to 4 periods of 1981, 1987, 1993, and 2002. For this, it designated the class of hydrosphere, vegetation, etc and achieved overlay analysis with extracting only the hydrosphere, and though this, These study monitored the change about hydrosphere of Daecheong dam basin efficiently.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.3
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• pp.31-39
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• 2007

In this study, the hydrosphere change of the Daecheong dam basin was detected qualitatively and quantitatively using Landsat satellite images until recentness since the construction of Daecheong dam. The hydrosphere change of the basin was analyzed by applying supervised classification about Landsat satellite images which were classified according to the hydrosphere, vegetation, road and etc. for four distinct years which are 1981, 1987, 1993, and 2002 year. Landsat satellite images of each year were achieved overlay analysis with extracting only the hydrosphere, and though these results, the hydrosphere change of the Daecheong dam basin was monitored efficiently.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.6
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• pp.15-34
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• 2021

Syntaxonomy and Synecology on Quercus variabilis forests in Daecheong-dam basin was carried out using the methods of Braun-Blanquet phytosociology. 6 syntaxa classified as species compositions described were Quercus variabilis community, Platycarya strobilacea-Quercus variabilis community(typicum subcommunity, dictamnus dasycarpus subcommunity), Quercetum variabili-serratae, Zelkova serrata-Quercus variabilis community and Dendranthema boreale-Quercus variabilis community. All syntaxa were shown habitat environmental conditions including steep inclination of more than 30°, high rock exposure rate of more than 50% and South-facing slope. These communities excepting Dendranthema boreale-Quercus variabilis community classified as natural vegetation were identified as low emergence rate of annual plants and species compositions composed native species, so it was confirmed that relatively natural succession were proceeding well. Quercetum variabili-serratae and Dendranthema boreale-Quercus variabilis community distributed forested hillslope of open water edge were representative Quercus variabilis syntaxa in Daecheong-dam basin.

• Journal of Korea Water Resources Association
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• v.41 no.11
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• pp.1095-1106
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• 2008

Climate change and global warming are prevalent all over the world in this century and many researchers including hydrologists have studied on the climate change. This study also studied the impact of climate change on streamflows of a basin in Korea. The SWAT model was used to assess the impacts of potential future climate change on the streamflows of the Daecheong Dam Basin. Calibration and validation of SWAT were performed on a monthly basis for the year of 1982-1995 and 1996-2005, respectively. The impact of seven 15-year(1988-2002) scenarios were then analyzed for comparing it to the baseline scenario. Among them, scenario 1 was set to show the result of doubling $CO_2$, scenario 2-6 were set to show the results of temperature and precipitation change, and scenario 7 was set to show the result of the combination of climatologic components. A doubling of atmospheric $CO_2$ concentration is predicted to result in an maximum monthly flow increase of 11 percent. Non-linear impacts were predicted among precipitation change scenarios of -42, -17, 17, and 42 percent, which resulted in average annual flow changes in Daecheong Dam Basin of -55, -24, 25, and 64 percent. The changes in streamflow indicate that the Daecheong Dam Basin is very sensitive to potential future climate changes and that these changes could stimulate the increased period or severity of flood or drought events.

• Spatial Information Research
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• v.20 no.5
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• pp.25-35
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• 2012

This study compared the influence of water quality according to the data sources of spatial information. Firstly, land cover map was constructed through image classification of Daecheong-dam basin and the accuracy of image classification from satellite image showed high as 88.76% in comparison with the large-scaled land cover map in Ministry of Environment, to calculate Event Mean Concentration (EMC) by land cover that impact on the evaluation of nonpoint source pollutant loads. Also curve number and direct runoff were calculated by spatial overlay with soil map and land cover map from image classification. And Seokcheon and Daecheong-Dam basin showed high in the analysis of curve number and direct runoff. Samgacheon-Joint and Sokcheon-Downstream basin showed high in the nonpoint source pollutant loads of BOD from direct runoff and EMC. And Samgacheon-Joint and Bonghwangcheon- Downstream basin showed high in the nonpoint source pollutant loads of TN and TP. Nonpoint source pollutant loads from image classification were compared with those by the land cover map from Ministry of Environment to present the effectivity of nonpoint source pollutant loads from satellite image. And Daecheong-Dam Upstream basin showed high as 10.64%, 11.70% and 20.00% respectively in the errors of nonpoint source pollutant loads of BOD, TN, and TP. Therefore, it is desirable that spatial information including with paddy and dry field is applied to the evaluation of nonpoint source pollutant loads in order to simulate water quality of basin effectively.

• Spatial Information Research
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• v.12 no.1
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• pp.13-27
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• 2004

The current industrial development and the increase of population in Daecheong Reservoir basin have produced a rapid increase of wastewater discharge. This has resulted in problem of water quality control and management. Although many efforts have been carried out, reservoir water quality has not significantly improved. In this sense, the development of water quality management system is required to improve reservoir water quality. The goal of this study is to design a GIS-based water quality management system for the scientific water quality control and management in the Daecheong Reservoir. For general water quality analysis, WASP5 model was applied to the Daecheong Reservoir. A sensitivity analysis was made to determine significant parameters and an optimization was made to estimate optimal values. The calibration and verification were performed by using observed water quality data for Daecheong Reservoir. A water quality management system for Daecheong Reservoir was made by connecting the WASP5 model to ArcView. It allows a Windows-based Graphic User Interface(GUI) to implement all operation with regard to water quality analysis. The proposed water quality management system has capability for the on-line data process including water quality simulation, and has a post processor far the reasonable visualization for various output. The modeling system in this study will be an efficient NGIS(National Geographic Information System) far planning of reservoir water quality management.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.695-698
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• 2008

The SWAT model was used to assess the impacts of potential future climate change on the hydrology of the Upper Geum River Basin(UGRB). Calibration and validation of SWAT were performed on a monthly basis for 1982-1995 and 1996-2005, respectively. The impact of ten 15-year(1988-2002) scenarios were then analyzed relative to a scenario baseline. Among them, scenario 1-6 were set to show the sensitivity response. A doubling of atmospheric CO2 concentration was predicted to result in an maximum monthly flow increase of 11 percent. Non-linear impacts were predicted among precipitation change scenarios of -42, -17, 17, and 42 percent, which resulted in average annual flow changes in UGRB of -55, -24, 26, and 65 percent.

• Journal of Korea Water Resources Association
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• v.46 no.5
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• pp.505-517
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• 2013

In this study, water supply for Geum River Basin was calculated by regulating the future water supply of Dam with the future expected discharges. HadGEM2-AO, which is the climate change prediction model that KMA (Korea Meteorological Administration) recently introduced was used for this study. The data of weather stations within the Geum River basin was extracted with the new Greenhouse Gas RCP scenario. The runoff of Geum river basin was simulated using the ArcSWAT for the 1988~2010 period. After validating the model, the similarity of results between simulation and observation at the Yongdam Dam and Daecheong Dam was 92.25% and 95.40%, respectively, which shows a good agreement with observed data. As the result of analysis for the discharges, the discharges would increase 47.76% under the RCP4.5 scenario and 36.52% under the RCP8.5 scenario. Water balance analysis was conducted by the KModSim for predicting the water supply under the runoff variation. We analyzed the volume of water intake with national standard of water supply 95% by Dam Operation Manual. By the analysis under RCP4.5 scenario, $9.41m^3/s$, $24.82m^3/s$ of additional water supply is available on Yongdam Dam and Daecheong Dam. By the analysis under the RCP8.5 scenario, $6.48m^3/s$, $21.08m^3/s$ of additional water supply is available on Yongdam Dam and Daecheong Dam.

• Journal of Korean Society on Water Environment
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• v.21 no.5
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• pp.470-476
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• 2005

The Korean Water Quality Index (K-WQI) was applied to the rivers located in the watershed of Daecheong Lake to assess the status of river water quality, and propose potential target constituents for better water quality management in the watershed. The estimated K-WQI value for each river was varied from 70 to 90, and Youngdongcheon showed the worst score while Mujunamdeachen showed the best score. The total nitrogen (TN) and total coliform bacteria were identified as the most significant constituents that degrade the K-WQI values in the rivers. The correlation coefficients (r) were determined between K-WQI and the delivered specific load ($kg/km^2/yr$) of BOD, TN, and TP to justify potential target constituents that have a great influence on the improvement of K-WQI values. The results showed that TN (r=-0.86) and TP (r=-0.85) have a strong negative relationships with K-WQI, but BOD have almost no effect. This implies that BOD, the surrogate parameter for organic pollutants, is no more a feasible water quality variable for the water quality management in the study site.