• Journal of Industrial Technology
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• v.27 no.A
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• pp.77-83
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• 2007

In this research, we have selected the region of Jawoon river that is the area of high land vegetable growing in the upper Soyang Reservoir and we have observed actual floating materials that generate negative nutrition and turbidity of the Reservoir water and the changes of water quality by raining of each month for one year of 2005 in order to monitor the relationship of pollution sources by the outflow of rain water. In addition, we also have conducted statistical inspection methods such as correlation analysis and regression analysis on strength of raining force and rain continuance time among the elements affecting the outflow of floating materials.

• Journal of Industrial Technology
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• v.27 no.B
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• pp.221-227
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• 2007

This research investigates the turbidity and flow of river for an year, 2005, in order to examine the relation of the generation of turbidity according to the outflow of min water. For this research, the region of Jawoon river where is the area of high land vegetable growing in the upper Soyang Reservoir is selected to observe actual floating materials that generate negative nutrition and turbidity of the Reservoir water and the changes of water quality by raining of each month. In addition, the researcher has conducted statistical inspection methods, such as correlation analysis and regression analysis on strength of raining force, and rain continuance time among the elements affecting the outflow of floating materials.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.3
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• pp.101-112
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• 2019

This study developed selection criteria of small-scales reservoirs, having under $300,000m^3$ storage capacity, for the Emergency Action Plan(EAP) establishment in order to reduce the disaster risks of the reservoir's failures. Those reservoirs are out of ranges of Korean EAP establishment standard, but have potential risk of disasters as they have often failed by the recent extreme rainfall events and earthquakes, causing economical and life losses. The problem of reservoir aging is also one of the reasons of them. In this study, the developed selection criteria of small reservoirs for EAP establishment are storage capacity, embankment height, reservoir age, heavy rain factor and earthquake factor. These criteria were selected based on the review of the existing EAP establishment guidelines, analysis of the past dam failure cases, and the previous related studies. The quantification of these criteria were conducted for the practical applications in the fields, and applied to 67 previous failures in order to investigate the relation of each criteria with these failures. The earthquake factor found to be the highest relations followed by heavy rain factors, combination of earthquake and heavy rain factors, and reservoir age. The classification was made as observation and review groups for EAP establishments based on overlapping numbers of each criteria. This classifications applied to 354 reservoirs designated as having the potential disaster risk by MOIS, and showed 38.4% of observation and 11.9% of review groups. Anticipatory monitoring and regular inspection should be made by professional facility managers for the observation group, and necessity of EAP establishment should be assessed for the review group based on the downstream status and financial budget.

• Economic and Environmental Geology
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• v.32 no.2
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• pp.169-175
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• 1999

The water leakage of reservoir embankment usually occurs through water vein, which gives little influence on the embankment in a normal state. However, the embankment can be destroyed when the water level of reservoir increases with heavy rain in summer. Investigating the water vein and its path is therefore very important from the viewpoint of disater prevention and embankment protection. This paper presents survey results of one-meter-depth ground temperature and multi-point temperature logging in an embankment in Japan to delineate water veins and permeable formations. Four water veins have been predicted in the embankment by comparing measured one-meter-depth ground temperatures with the background ones which have no effect of water vein. The multi-point temperature logging was carried out in the borehole drilled at one of the predicted water veins. Depth and thickness of the permeable formation in the borehole can be determined from temperature restoration ratios with elapsed time. From these results we can find that the water leakage of reservoir embankment mainly occurs in sandy soil formation in the embankment.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.207-212
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• 2005

It was convenient and the maintenance to do ease, to tilt the effort of one irrigation facility modernization by used to solar energy of reservoir flood gate and to reach and to lead in order to prepare one hand insufficiently it follows in leaving farming of the farming village and become older in age of the irrigation facility manager, it discussed one result. The reservoir flood gate which currently is developed but as improving the circular floodgate rain it does not measure the flow which is accurate is supplied from the reservoir it could not.

• Journal of Korean Society on Water Environment
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• v.27 no.1
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• pp.88-97
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• 2011

To identify the inflow and outflow characteristics of allchthonous organic matters and examine the change of allochthonous organic matter load pattern due to the climate change, we investigated the temporal variations of DOC and POC concentrations within inflow water and dam discharge water and spatio-temporal distribution of POM within the lake water in Lake Soyang which is the largest dam reservoir in Korea in 2006. Most of allochthonous DOC flowed into the lake water during initial rain and was not affected by the amount of precipitation, whereas most of allochthonous POC flowed into during concentrated heavy rain and the concentration of POC was significantly associated with the amount of inflow water and precipitation. Calculated annual allochthonous organic matter loads in Lake Soyang from 2003 to 2006 using the regression equation between the amount of inflow water and the concentration of POC indicate allochthonous organic matter loads are mainly affected by total influx and extreme influx of inflow water. The spatio-temporal distribution of POM indicated allochthonous organic matter of inflow river during flood period in July transported from upper part to middle and lower part of the lake a month later respectively along the middle layer of water column in Lake Soyang.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.2
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• pp.459-466
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• 2017

Several reservoirs that were managed by local governments and the Korea Rural Community Corporation have recently collapsed. One of them is the Goeyeon reservoir in Yeongcheon-si, Gyeongsangbuk-do that collapsed mainly around the spillway due to heavy rain at 9 O'clock, on 21 August 2014. The Goeyeon reservoir was an aging agricultural reservoir over 70 years since it was built. In this study, the collapse situation of the reservoir was reproduced through the DAMBRK model. Flood inundation maps were reconstructed for the breach outflow of the dam analyzed by the DAMBRK model. We estimated the breach duration and outflow of the reservoir as compared with the inundation image taken by the Unmanned Aerial Vehicle (UAV) at the time when the Goeyeon reservoir collapsed. The results of this study are expected to be useful for predicting damage in the downstream inundation area when a reservoir collapses.

• Korean Journal of Ecology and Environment
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• v.38 no.1 s.110
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• pp.105-117
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• 2005

During the period of heavy rain from 2002 to 2004, the characteristics of the inflow, temporal and spatial fluctuations of high turbid water according to thermal stratification were studied on the Andong Reservoir which is the largest artificial lake in the Nakdong River basin, Korea. Thermal stratification was formed in June. Its structure determined to the pathway of inflowing turbid water and has affected by the transportation of high turbid water. Regardless of the time and amount of inflow, the high turbid water showed the shape of underflow at the riverine zone, separated from the bottom at the transition zone and moved to the lacustrine zone with the shape of density current. The plunging point depended on the time and amount of inflow. The distributions of thermal stratification and DO concentrations were changed by inflowing discharge. Two thermoclines and minimum DO layers were found out existing at metalimnion in a specific time, respectively. The layer of high turbid water which formed with the thickness of 20 m at the maximum below the depth of 15 m moved toward dam. Not settled to the bottom, the newly formed layer was discharged through the intake-outlet and dispersed into all layers by the circulation in the fall.

• Journal of Korea Water Resources Association
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• v.47 no.2
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• pp.107-117
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• 2014

Hancheon reservoir, which is located upstream of Jeju city, has been built for flood mitigation after Typhoon Nari, 2007. To verify flood mitigating effect of the this reservoir on the downstream area, runoff analysis based on the measured data (two stream discharge monitoring stations and inflow data to the reservoir) is carried out during torrential rain followed by typhoon Dainmu, 2010. The stream water level was recorded as 3.14 m for the peak at the down gradient station. The stream water level under the assumption of absence of Hancheon reservoir is calculated as 4.16 m using the estimated rating curve, stream water propagation velocity, and the bypassed volume of water to the reservoir. This result shows that clear effect of reservoir operation which is capable of mitigating peak discharge in the downstream area.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.2
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• pp.59-66
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• 2010

This study was performed to develop the embankment protection method that can reduce demage by prevention of embankment loss and collapse from overflow due to heavy rain and flood. For overflow test, model dam was prepared and embankment behaviors were monitored with the established piezometer and strain meter during overflow. As a result of overflow test for model dam, in case of embankment without waterproof mat, the lower end of embankment was collapsed within 40 seconds after beginning of overflow. On the other hand, in case of embankment with waterproof mat, embankment collapse didn't occurred during overflow. Accordingly, establishment of waterproof mat for embankment showed that be absolutely effective for the embankment protection during overflow in reservoir. Also, it showed that the minimum establishment range of waterproof mat to prevent embankment collapse in reservoir is from maximum storage level to the lower end of embankment.