• 한국석유지질학회:학술대회논문집
• /
• spring
• /
• pp.29-37
• /
• 1998

The sedimentary succession on the northern coast of Jindo and the adjacent area comprises the thinly bedded, fine-grained deposits of an epiclastic sandstone, siltstone, black shale/mudstone, and cherty mudstone (ca. 200m in vertical thickness), which are interpreted as the finely stratified turbidites mainly by density underflow-induced currents. Most deposits can be divided into eight facies: thin-bedded, ash-rich massive sandstone layer (mS), graded and laminated mudstone layer (glM), graded mudstone layer with ripple lamination (rM), laminated and graded siltstone layer (lgZ), finely laminated black shale layer (IBS), structureless mudstone layer (mM), thin-bedded cherty mudstone layer (lCM), and contorted and laminated mudstone layer (dlM), The thin-bedded, ash-rich sandstone facies is interpreted to be deposited from high-density turbid underflows during a relatively large flooding. Most thinly bedded mudstone facies would be deposited from low-density turbid underflows (turbidity currents) with some different hydrodynamic condition and sediment concentration during the high discharge of river water. Whereas the structureless mudstone facies may result from raining down of suspended sediment intermittently supplied by overflows and interflows. From the entire succession, graded and laminated mudstone layers interbedded with thin-bedded, ash-rich massive sandstone are dominant in the lower part of the succession, and graded mudstone layers with ripple lamination ripple lamination occur mainly in the middle part of it. On the other hand, iaminated/raded siltstone and contorted/laminated mudstone layers prevail in the upper part. The transition of facies association is suggestive of the continuous change of main depositional setting from basin plain to lower slope, which could be due to the movement of depocenter by the increase of sediment supply (volcanic activity).

• Transactions of the Korean hydrogen and new energy society
• /
• v.24 no.3
• /
• pp.216-222
• /
• 2013

Durability characteristics of Gas Diffusion Layer(GDL) is one of the important issues for accomplishing commercialization of Proton Exchange Membrane Fuel Cell(PEMFC). It is strongly related to the performances of PEMFC because one of the main functions of GDL is to work as a path of fuel, air and water. When the GDL does not work on their proposed functions due to the degradation of durability, mass transfer in PEMFC is disturbed and it might cause the flooding phenomenon. Thus, investigating the durability of GDL is important and understanding the GDL degradation process is needed. In this study, electrochemical degradation with carbon corrosion is introduced. The carbon corrosion experiment is carried out with GDLs which have different MPL penetration thicknesses. After the experiment, the amount of degradation of GDL is measured with various properties of GDL such as weight, thickness and performance of the PEMFC. The degraded GDL shows loss of their properties.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.26 no.3
• /
• pp.140-148
• /
• 2014

A storm surge barrier is a specific type of floodgate, designed to prevent a storm surge or spring tide from flooding the protected area behind the barrier. A surge barrier is almost always part of a larger flood protection system consisting of floodwalls, dikes, and other constructions. Surge barriers allow water to pass under normal circumstances but, when a (storm) surge is expected, the barrier can be closed. Among the various means of closing, buoyant flap typed storm surge barrier which was indicated by MOSE project in Italy is chosen for Masan bay protection, and the motion of the surge barrier under the action of storm surge and wave is examined using FLOW-3D, a computational fluid dynamics software analyzing various physical flow processes. Numerical result shows that storm surge barrier is successfully operated under wave height 3 m, and tidal range 2 m.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.16 no.2
• /
• pp.137-153
• /
• 2013

In order to assess the effects of ecosystem and landscape in around spur dikes, this study had carried out monitoring on the changes of ecosystem and morphologic characteristics in around spur dikes that had been settled in bend of Youngcheon River. The study site was a short reach with length 190m, spur dikes were installed in March, 2008. Monitoring of the site had been started in May 2008 and had been completed September 2011. The results are as follow ; 1) Spur dikes that were installed for channel stabilization are performing effectively hydraulic functions at flooding time. 2) Spur dikes that were installed in water colliding front of river bend brought about sediment deposition between those and formed pools around front of those. Therefore, it was verified to create various physical characteristics in the aspect of channel topography and flow consequently. 3) The survey results that was carried out in October 2008 showed to emerge 25 species of plant, 9 species of fish and 17 species of benthic macroinvertebrates, but the survey results in October 2010 showed to emerge 74 species of plant, 12 species of fish and 19 species of benthic macroinvertebrates. In particular, plant species that emerged in 2011 increased about three times more than those in 2008.

• Journal of the Korean association of regional geographers
• /
• v.16 no.5
• /
• pp.457-473
• /
• 2010

Patterns and regional distribution of disaster-related place names have been analyzed to confirm the recognition and probability of disaster and to explore the possibility of disaster prevention measures. 106 terms and 37,901 place names related to disaster and prevention measures have been collected from the Korean gazetteers "Hanguk Jimyeong Chongnam". Based on this, some conclusions have been drawn: firstly, place names related to the geomorphic processes and prevention measures are more common than any other disasters; secondly, place names related to heavy rain, flooding and drowning are most common. Analysis of the regional distribution pattern shows that disaster-related place names are most common in Jeolla and Gyeongsang Provinces and general place names reflecting environmental concern such as water, sand, plain, rain and dam are distributed evenly throughout the whole country; howe, r, place names such as dumbeong, gureong, yeoul, tan(灘), bangjuk, je(堤), and ji(池) are restricted to the specific region, which shows that place names reflects the locational and toprn sucic ainuations. Case st, anindicates that prevention measures should be focused on tributaries and srill villeys conaid ring that disasters originated from the combination of weather and landform conditions are most common throughout the whole country.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.12 no.1
• /
• pp.141-150
• /
• 1992

Rapid change of urban area become a serious cause of disaster in existing drainage systems, and the practical alternatives in that situations are needed. The purpose of this study is to evaluate safety, one of drainage systems, detention reservoir and pumping station by new pumping criteria. New drainage pumping criteria, divided into two parts (rising limb and falling limb), which used in reservoir routing, shows more efficient flood prevention effect than existing criteria (based on the reservoir water level). To obtain the optimal range of flood prevention, sensitivity analysis of each inflow v.s. pumping capacity is tested. As a results, using 10 year design rainfall, 60% of detention reservoir and drainage pumping stations in Seoul are safe. In this results, there must be a fundamental and powerful counterplans to prevent inland flooding in Seoul metropolitan area.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.4 no.4
• /
• pp.56-63
• /
• 2001

This paper presents treatment efficiency and plant growth of a subsurface-flow constructed wetland system (23 m in length, 6.5 m in width, 0.65 m in depth) over one year after its establishment on floodplain of a stream in June 2000. An upper layer of 10 cm in depth was filled with course sand and the main biological layer of 50 cm depth with crushed stone with 8 - 15 mm in diameter. The system was planted with common reeds (Phragmites australis) grown on pots. Effluent discharged from a secondary-level treatment plant was funneled into it. Reed stems emerging in April 2001 grew up to 145.9cm until July 2001. The number of reed stems in July 2001 increased by about 11 times compared with that just after planting. The system was inundated seven times by storms over the monitoring period. Reeds were slightly bent after flooding, however they returned to almost upright standing in a couple of weeks. Small portion of inside slope of berm was eroded and the system surface had a sedimentation of 2 - 3 mm in depth. The average removal rates for SS, $BOD_5$, T-N and T-P was 73%, 70%, 53%, and 72%, respectively. The purification efficiencies for SS and $BOD_5$ were fairly good. The reduction rates for T-N was relatively low for the period of late fall through winter until early spring due to lower water temperature which retarded microbial nitrification and denitrification mechanisms. Reduction in the concentration of T-P during fall and winter was relatively higher than that during spring. Leach of phosphorous from plant litters lying on system surface and slight resuspension of precipitated phosphorous in substrates resulted in lower reduction for T-P in spring.

• KIEAE Journal
• /
• v.16 no.1
• /
• pp.67-71
• /
• 2016

Purpose: There is a growing interest in rainwater runoff reduction effect of green roof, as flooding caused by increasing impervious surface is becoming more and more frequent in urban areas. This study was conducted to prove runoff reduction and runoff delay effect of the retentive green roof and to investigate its influencing factors to the rainfall events that occurred in the summer of 2013. Method: The experiment intended to monitor the runoff quantity of the retentive green roof($140m^2$) and normal roof($100m^2$) in #35 building in Seoul National University, Seoul, Korea for 75 days in 2013. Result: On analysis of 9 rainfall events, it showed that the retentive green roof has 24.8~100% of runoff reduction ratio, 21.2~100% of peak flow reduction ratio, 0.5~3.75 hours of peak delay, and $1.8{\sim}7.2m^3$ of retaining capacity in an area of $140m^2$. It shows different results depending on rainfall and antecedent dry days. The results show that runoff reduction effect is effective when the rainfall is less than 50 mm and antecedent dry day is longer than five days on average. By installing retentive green roofs on buildings, it can help mitigate urban floods and rehabilitate urban water cycle.

• Resources Recycling
• /
• v.2 no.4
• /
• pp.1-9
• /
• 1993

A study on the recovery of nitric and hydrofluoric acids is carried out with pulsed column extractor in order to the industrial application of this process. Firstly, from the continuous experiments about the recovery of acids using domestic stainelss steel pickling solution, it is found out that the free nitric and hydrofluoric acids are only extracted by 70% TBP and the heaby metals such as Fe, Cr and Ni are not extracted. The effectiveness of extraction and stripping generally improves as the pulse velocity(product of amplitude and frequency) is increased, optimum performance typically occuring slightly below an amplitude-frequency product which results in flooding the column because of excessive emulsification. When the pickling solution is treated by 70% TBP at a phase ratio of A/O=1/2 in the extraction and by distilled water at a phase ratio of O/A=1 in the stripping, the concentration of refined acides are 102g/$\ulcorner$ $HNO_3$and 8.8g/$\ulcorner$ HF, respectively and the recovery of $HNO_3$and HF are 90.7% and 75.2%, respectively.

• Korean Journal of Soil Science and Fertilizer
• /
• v.49 no.6
• /
• pp.682-688
• /
• 2016

Food waste has recognized one of useful sources for potentially agricultural application to supply organic matter and nutrients in arable soil. However, there was little information on application of food waste compost related to the maturity and NaCl content in arable soil. This study evaluated the effect of food waste compost application on yield and fertility in soil under flooding and upland condition. The yields in rice and pepper cultivation decreased with increasing the rate of food waste compost application in soil (p<0.05). Maximum yields of rice ($49.0g\;plant^{-1}$) and pepper ($204g\;plant^{-1}$) were shown at 10 and $30Mg\;ha^{-1}$ of food waste compost application, respectively. The N, P, and K contents in grain and plant residues increased by the application of food waste compost, there was no difference on Na/K ratio in plant tissue among the treatments. Application of food waste compost resulted in the increase of pH, EC, TC, available P contents in soil after crop harvest, especially, which was shown the increase of the CEC and exchangeable sodium percentage (ESP) contents in irrespective of water condition. In conclusion, application of food waste compost in soil was effective on the supply of the organic matter and nutrient. However, it might need caution to apply food waste compost for sustainable productivity in arable soil because of potential Na accumulation.