• Journal of Korean Society on Water Environment
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• 제34권3호
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• pp.293-300
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• 2018

Ihe purpose of this study is to evaluate the effects the storage type of permeable concrete block paving (ST-PCBP) have on runoff reduction and infiltration increasement at Andong Maskdance Festival Square. This was accomplished using the NRCS-curve number method over the last 10 years. Two different scenarios were developed in this study for low impact development (LID) design. For the $1^{st}$ scenario, the walking path and parking lot were install using the ST-PCBP and runoff from the inline skating rink ($3,808m^2$) and lawn ($11,191m^2$) were routed to the ST-PCBP, but the rooftop runoff flowed into the storm water drainage system. For the $2^{nd}$ scenario, one of the non-structural BMPs, disconnected impervious surface (DIS), was applied so additional runoff from rooftop would enter the ST-PCBP. It was determined that ST-PCBP could significantly reduce surface runoff from the study area and increase infiltration with 71% and 88% of surface runoff reduction and 151% and 215% of infiltration increasement for scenarios 1 and 2, respectively. The effect of LID in the $2^{nd}$ scenario was better than the $1^{st}$ scenario, therefore DIS in conjunction with ST-PCBP could be a more cost-effective LID application.

• Journal of Korean Society of Water and Wastewater
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• 제27권2호
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• pp.197-206
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• 2013

Recently, climate change causes climatic anomaly such as global warming, the typhoon and severe rain storm etc. and it brings damage frequently. 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. In this study, Seonakdong river watershed in the Nakdong river basin was selected as a study area. Real-time monitoring system was used to draw the rating curves, which has 0.78 to 0.96 of $R^2$. To predict runoff change in Seonakdong river watershed caused by climate change, the change in hydrologic runoff were predicted using the watershed model, SWAT. As a result, the runoff from the Seonakdong river watershed was increased by up to 45 % in summer. Because of the non-point sources from the farmland and the urban area, the water quality will be affected by the climate change. In this study, the operating plan of the water gates in Seonakdong river will be suggested by considering the characteristics of the watershed runoff due to the climate change. The optimal watergate opening plan will solve the water pollution problems in the reservoir-like river.

• Journal of The Korean Society of Agricultural Engineers
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• 제48권4호
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• pp.77-86
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• 2006

This study was performed to investigate the stream water quality characteristics in the Dowoncheon basin of Dongjin River during the 12 months from January to December in 2005. Also, pollutant loads were calculated on the basis of the water quality and runoff results. The measured pH and EC of the stream water were ranged 6.48-7.32, $18.06{\sim}38.60{\mu}S/cm$, respectively. The concentration of DO, BOD, COD, SS, T-N and T-P were observed as 4.90-11.50 mg/L, 0.5-6.0 mg/L, 1.22-18.46 mg/L, 1.0-2,124.0 mg/L, 1.35-5.67 mg/L, 0.02-0.43 mg/L respectively. T-N showed low correlativity with other water quality parameters. However, T-P had very high correlativity with COD and SS. In the meantime, the runoff pollutant loads of T-N, T-P were estimated as 72,114 kg/yr, 5,027 kg/yr. In the case of the correlativity between runoff pollutant loads and concentrations, T-N did not show significant relationships, while T-P had significant relationships.

• Journal of Wetlands Research
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• 제13권3호
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• pp.707-720
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• 2011

For the lake case, the detention phenomenon of water body occurs and stays for a long time. Especially, following the layer of water depth direction, the lake body and water quality problems are different from the water quality of river. So according to time, the stream and water quality can be simulated by the 3-Dimensional Model, which can divide water layer for reservoir or lake. The water quality simulation result will become more reliability. For this study, the 3-Dimension Model - EFDC was used to simulate water quality of Unam reservoir in the Sumjin Dam. The HEC-GeoHMS and HEC-HMS Rainfall - Runoff Model based on GIS were used to estimate long-term runoff, and input data was constructed to the observed water level, meteorological data, water temperature, T-N and T-P. In order to apply the EFDC model, water depth was divided into 3 layers and 5,634 grids were extracted. After constructing the grid net, the water quality change of Unam reservoir in time and space was simulated. Overall, long term runoff simulation reflected the actual observed runoff well, through the water quality simulation, according to the pollution factors, the behavior characteristics can be checked, and the simulated water quality can be properly reflected. The function of EFDC has been confirmed, which water quality can be properly simulated. In the near future, to establish countermeasures for Intake Facilities of Watershed and Management, this support which some basic tools can be applied is in expectation.

• Journal of Korean Society on Water Environment
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• 제21권2호
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• pp.184-189
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• 2005

Impacts of non-point source pollution on water quality are well known. In this paper, effects of land use, precipitation characteristics, discharge characteristics on non-point source pollutant loadings at urban, agricultural and forestry watersheds were discussed. Rainfall runoffs from fifteen rainfall events were sampled and analysed at two urban watersheds, one rural watershed, and one forestry watershed. EMCs (Event Mean Concentration) were calculated based on monitored flow rates and concentrations. Statistical analysis carried out with runoff loadings and affecting variables indicated that runoff loadings are weakly correlated with the rainfall intensity and the dry days before rainfall events while showed no correlations with rainfall depth nor runoff quantity. By comparing EMCs between study watersheds on log-normal cumulative probability scale, EMCs ranking were in the descending order of urban watershed>agricultural watershed>forestry watershed for SS, TCOD, TN, and TP.

• Journal of Korea Water Resources Association
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• 제44권8호
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• pp.683-694
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• 2011

To analyze the regional impact of air temperature increase and precipitation variation on water resources, the variability of precipitation-effectiveness (P-E) ratio which is estimated using precipitation and air temperature data of 59 weather stations operated by the Korean Meteorological Administration (KMA) during 1973~2009 was analyzed. Also runoff data resulting from the Precipitation-Runoff Modelling System (PRMS) modelling were analyzed during 1966~2007. The overall spatio-temporal variability of P-E ratio and runoff data in South Korea is corresponding to the variability of precipitation amount. However some region shows that the P-E ratio decreases even though the trend of precipitation amount increases which may be caused by the air temperature increase. Runoff trend is similar to that of P-E ratio. Precipitation and P-E ratio have decreased all seasons except summer season and it means the reduction of available water resources during those seasons. These variability should be reflected in the spring, fall, and winter water supply strategy.

• Magazine of the Korean Society of Agricultural Engineers
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• 제43권5호
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• pp.153-162
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• 2001

A study was carried out to investigate the water balance and losses of nutrients at a paddy plot located at the southern Korea. The observed amount of precipitation, irrigation, runoff, evapotranspiration and percolation for the experimental paddy plot during cropping period were 1,030, 566, 701, 551. and 310 mm for 1999 and 1.214, 413, 710, 682, and 234 mm for 2000 year, respectively. The measured input quantities of N and P into the paddy field during cropping period were 122 to 140 kg N $ha^-1$ and 29 to 30 kg $P_2O_5$ kg $ha^-1$ by chemical fertilizer, 20 to 28 kg N $ha^-1$ and 0.35 to 0.36 kg P $ha^-1$ by precipitation, and 26 to 35 kg N $ha^-1$ and 0.57 to 0.72 kg P$ha^-1$ by irrigation water. respectively. The output amounts of N and P from paddy field were measured as follows. They were 48 to 52 kg N $ha^-1$ and 1.1 to 1.6 kg P $ha^-1$by runoff water, and 9 to 12 kg N $ha^-1$ and 0.04 to 0.05 kg $ha^-1$ by percolation water. When the runoff losses of nutrients were compared to applied chemical fertilizer. it was found that 34.3 % to 42.6 % of nitrogen lost via runoff while runoff losses of phosphorus account for 3.8 % to 5.3 % of the total applied amount. When the ratio was calculated between nutrients losses by percolation water and the applied of chemical fertilizer, two year results showed 6.4 % to 9.8 % for the nitrogen and 0.1% to 0.2% phosphorus, respectively.

• Water for future
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• 제16권1호
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• pp.49-56
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• 1983

A STUDY ON THE ESTIMATION OF THE AVAILABLE WATER RESOURCES IN KOREA The purpose of this study is to present the estimated the total amount of runoff in Korea. The annual mean runoff is estimated by cumulating daily discharges that obtaine from daily stages on the rating curve. The selected five major gaging stations(Indogyo, Gyuam, Jindong, Naju, and Songjeong) to take the daily discharges stand for the five major streams such as the Han River, the Geum River, the Nokdong River, the Yeongsan River and the Seomjin River. The results of this study are as follows; 1) The maximum quantity of the total available water resources is estimated at 26,900 million cubic meters, the minimum is 24,300 million, and the annual mean quantity is 25,600 million 2) The annual mean rate of runoff is evaluated about 58 percent in the five major basins. 3) The annual mean rate of runoff over inland is estimated about 57 percent as a result of assuming the runoff rate of 5 zone about 80 percent, the annual mean rate of runoff is estimated about 56 percent except for V-zone in analysis.

• Proceedings of the Korea Water Resources Association Conference
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• 한국수자원학회 2021년도 학술발표회
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• pp.130-130
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• 2021

The increasing effect of urbanization has been more apparent through flooding and downstream water quality especially from heavy rainfalls. In response, stormwater runoff management solutions have focused on runoff volume reduction and treatment through infiltration. However, there are areas with low infiltration soils or are experiencing more dry days and even drought. In this study, a lab-scale infiltration system was used to compare the applicability of two types of soil as base layer in gravel-filled infiltration systems with emphasis on runoff capture and suspended solids removal. The two types of soils used were sandy soil representing a high infiltration system and clayey soil representing a low infiltration system. Findings showed that infiltration rates increased with the water depth above the gravel-soil interface indicating that the available depth for water storage affects this parameter. Runoff capture in the high infiltration system is more affected by rainfall depth and inflow rates as compared to that in the low infiltration system. Based on runoff capture and pollutant removal analysis, a media depth of at least 0.4 m for high infiltration systems and 1 m for low infiltration systems is required to capture and treat a 10-mm rainfall in Korea. A maximum infiltration rate of 200 mm/h was also found to be ideal to provide enough retention time for pollutant removal. Moreover, it was revealed that low infiltration systems are more susceptible to horizontal flows and that the length of the structure may be more critical that the depth in this condition.

• Water for future
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• 제29권6호
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• pp.131-139
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• 1996

The main goal of this study is a rainfall-runoff analysis using atopographically-based distributed model. It consists of two parts: one is a direct runoff submodel and the other is a baseflow submodel. The direct runoff submodel is a distributed model which routed through the drainage networks with a kinematic wave model. The baseflow submodel is considered as a lumped system. This model makes it possible to take the effect of areal and temporal distribution of storm into accout.