• The Journal of Engineering Geology
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• v.17 no.2 s.52
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• pp.177-185
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• 2007

Most of hot springs don't spring out naturally but are pumped by submersible pumps in Korea. When pumped piezometric head in a well is dropped with proportion to quantity. This research investigates relationships between quantity and drawdown at the Onyang hot spring area. There are 38 wells at this area and the depths of wells range from 124 m to 303 m. Piezometric heads of 4 wells were observed for about 10 months. Fluctuation patterns of piezometric heads seem to be a sine curve with a you period by a high demand and a slack season. Drawdowns of fluctuations were about 98-139 m depth to water table when wells were pumped at $2,300-4,800m^3/day$. A equation was made through analyzing quantity and drawdown.

• Ocean and Polar Research
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• v.36 no.4
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• pp.437-445
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• 2014

A time-series sediment trap was operated at a water depth of 4950 m from July 2003 to May 2004 at KOMO station ($10^{\circ}30^{\prime}N$, $131^{\circ}20^{\prime}W$) in the northeastern equatorial Pacific, with the aim of understanding the temporal variation of planktonic foraminifera assemblages in response to the seasonal shift of Inter-Tropical Convergence Zone (ITCZ). A total of 22130 planktonic foraminifera specimens belonging to 30 species and 11 genera were identified, which shows a distinct seasonal variation with high values (125~288 specimens $m^{-2}day^{-1}$) in the winter to spring (December-May) and low values (16~23 specimens $m^{-2}day^{-1}$) in the fall (September-November). In addition, seasonal ecological differences of foraminifera assemblages are distinctly recognizable: omnivorous foraminifera occurred predominantly during the summer season, whereas herbivorous ones were dominant during the winter season. Such seasonal variations correspond to the seasonal shift of the ITCZ. Enhanced occurrence of herbivorous species during the winter-spring season seems a result of surface water mixing generated by the southward shift of the ITCZ. The increase in omnivorous species during the summer season may be due to the northward movement of the ITCZ caused by weakened wind speed, resulting in the intensification of water column stratification and nutrient-poor environment. A significant reduction of planktonic foraminifera specimens during the fall is attributed to heavy precipitation and reduction in light intensity.

• Journal of the Korean earth science society
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• v.35 no.2
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• pp.97-103
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• 2014

An isotopic hydrograph separation technique has been able to determine the contribution of new water (event water such as rain or snowmelt) and old water (pre-event water like groundwater) to a stream hydrograph for last several decades using stable water isotopes. It is based on the assumption that the isotopic compositions of both new water and old water at a given instant in time are known and the stream water is a mixture of the two waters. In this study, we show that there is a systematic error (standard error in the new water fraction) in the isotopic hydrograph separation if the average isotopic compositions of new water were used ignoring the temporal variations of those of new water. The standard error in the new water fraction is caused by: (1) the isotopic difference between the average value and temporal variations of new water; (2) the new water fraction as runoff contributing to the stream during rainfall or spring melt; and (3) the isotopic differences between new and old water (inversely). The standard error is large, in particular, when new water dominates the stream flow, such as runoff during intense rainfall and in areas of low infiltration during spring melt. To reduce the error in the isotopic hydrograph separation, incorporation of fractionation in the isotopic composition of new water observed at a point should be considered with simultaneous sampling of new water, old water and stream water.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.331-335
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• 2004

This study is focused to analyze the movement of thermal effluent dischargeed from nuclear power plant by season, ebb and flow, and before and after foundation of tide embankment using thermal infrared band image of 28 scenes observed from Landsat from 1987 to 2004, which is the early stage of operation of young-kwang nuclear power plant. In diffusion of thermal effluent discharge by seasons, spring and summer is spreading further than autumn and winter. It is considered to distribute widely mixed with thermal effluent discharge and hot water, which is distributed naturally along the seaside. It is known the fact that tidal currents control the direction of diffusion of thermal effluent discharge by the change of ebb and flow. Namely, it is distributed widely on the Southwest direction along the seaside by tidal currents when ebb and, it is moved widely on the Northeast direction along the seaside by tidal current when flood. However, in the early stage of flood current, the mainstream of thermal effluent discharge is spread on Southwest direction and, the direction is changed on North­east way when the latter period of flood current. Similarly, in the early stage of ebb current, the mainstream of thermal effluent discharge is spread on Northeast direction and, the direction is changed on Southwest direction when the latter period of ebb current. As the result of comparing to the diffusion pattern of thermal effluent discharge before and after the foundation of seawall, discharged thermal effluent from the drain of plant by the foundation of dike is shown as curved circle pattern on Northeast to West direction from the ending portion of the seawall.

• Journal of Soil and Groundwater Environment
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• v.25 no.4
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• pp.14-27
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• 2020

The drought has occurred from the past, and has caused a lot of damage. It is important to analyze the past droughts and predict them in the future. In this study, the temperature and precipitation of the past and the future from climate change RCP 4.5 and 8.5 scenarios were analyzed for Seosan and Boryeong in the western region of Chungnam Province, which is considered as a drought-prone area on the Korean Peninsula. Comparing Standardized Precipitation Index (SPI) and Effective Drought Index (EDI) based on the past droughts, EDI was verified to be more suitable for the drought assessment. According to RCP 4.5, the frequency and intensity of droughts in the early future (2021~2060) were expected to increase and to be stronger. Particularly, severe droughts were predicted for a long time from 2022 to 2026, and from 2032 to 2039. Droughts were expected to decrease in the late future (2061~2100). From RCP 8.5, drought occurrences were predicted to increase, but the intensity of the droughts were expected to decrease in the future. As a result of evaluation of the frequencies of droughts by seasons, the region would be most affected by fall drought in the early future and by spring drought in the late future according to RCP 4.5. In the case of RCP 8.5, the seasonal effects were not clearly distinguished. These results suggest that droughts in the future do not have any tendency, but continue to occurr as in the past. Therefore, the measures and efforts to secure water resources and reinforcement of water supply facilities should be prepared to cope with droughts.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.4
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• pp.81-93
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• 2022

There are many natural hot springs and mineral springs as well as the cultural heritage of the three kingdoms period in the Geum River basin including Chungcheong region. No specific regeneration and publicity plans for deteriorated facilities in this area has been presented. This study aims to suggest promising hot spots and complex water culture belt in the Chungcheong region and Geum River basin through the spatial interpretation of resources. The northern part of the Geum River basin is expected to become a therapeutic spring belt with many hot springs and CO₂-rich springs. In the central and southern parts of the Geum River basin, it is considered that it will be possible to promote convergence publicity by using groundwater resources and cultural assets.

• Journal of Environmental Impact Assessment
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• v.25 no.3
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• pp.209-221
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• 2016

The section from water source to 2.6km upper stream of Hantan River is protected as the drinking water quality protection area according to guidelines of Ministry of Environment, because water source of the Gwanin water intake plant has been known the river. However, opinions were consistently brought up that the standard of water source protection zone must be changed with using underground water as water source because of contribution possibility of underground water as the water source of Gwanin water intake facility. In this regard, hydrogeologic investigation including resistivity survey and hydrogeochemical investigation were carried out to assess water source and infiltration of contaminant for the plant. Quaternary basaltic rocks (50m thick with four layers) covered most of the study area on the granite basement. As the result of the resistivity survey, it is revealed that permeable aquifer is distributed in the boundary of two layers: the basaltic layer with low resistivity; and the granite with high resistivity. Considering of outflow from Gwanin water intake facility, the area possessing underground water was estimated at least $5.7km^2$. The underground water recharged from Cheorwon plain was presumed to outflow along the surface of unconformity plane of basalt and granite. Based on field parameters and major dissolved constituents, groundwater and river water clearly distinguished and the spring water was similar to groundwater from the basaltic aquifer. Temporal variation of $SiO_2$, Mg, $NO_3$, and $SO_4$ concentrations indicated that spring water and nearby groundwater were originated from the basaltic aquifer and other groundwater from granitic aquifer. In conclusion, the spring of the Gwanin water intake plant was distinguished from river water in terms of hydrogeochemical characteristics and mainly contributed from the basaltic aquifer.

• The Journal of Engineering Geology
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• v.28 no.4
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• pp.565-582
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• 2018

We investigated the hydrochemical properties of ChusanYongchulso Spring located in Buk-myeon, Ulleung Island, focusing on the formation and characteristics of aquifers in and around the Nari caldera. Abundant pumice with high permeability and numerous fractures (including faults and joints) that formed as a result of caldera subsidence are widely distributed in the subsurface, favoring the formation of aquifers. Because of the presence of porous pyroclastic rocks with a high internal surface area, the water type of the springs is characterized by $NaHCO_3$, with upper stream waters and the upper spring being characterized by $NaHCO_3$ and NaCl, respectively. Components with a high coefficient of determination with EC are $HCO_3$, Na, F, Ca, Mg, Cl, $SiO_2$, and $SO_4$. The high concentrations of Na and Cl might be attributable to the main lithologies in the area, given that alkaline volcanic rocks are distributed extensively across Ulleung Island. Eh and pH, which are considered to be important indicators of water-rock interaction, are unrelated to most components. According to the results obtained from factor analysis, the variance explained by factor 1 is 54% and by factor 2 is 25.8%. Components with a high loading on factor 1 are F, Na, EC, Cl, $HCO_3$, $SO_4$, $SiO_2$, Ca, $NO_3$, and Mg, whereas components with a high loading on factor 2 are Mg and Ca, along with K, $NO_3$, and DO with negative loadings. It is suggested that the high concentrations of Na, Cl, F, and $SO_4$ are closely related to the presence of fine-grained alkaline pyroclastic rocks with high permeability and porosity, which favorintensewater-rock interaction. However, a wide-ranging investigation that encompasses methods such as geophysical prospecting and geochemical analysis (including isotope, trace-element, and tracer techniques) will be necessary to gain a better understanding of the groundwater chemistry, aquifer distribution, and water cycling of Ulleung Island.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.1
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• pp.9-20
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• 2007

This experiment was conducted to investigate effects of application of diluted and undiluted cattle slurry with water on seasonal and annual dry matter yields and feed values of tall fescue in the uncultivated rice paddy and it was compared with chemical fertilizer in order to determine optimal application season and dilution level of cattle slurry. When diluted or undiluted cattle slurry with water was applied to uncultivated rice paddy, annual dry matter yields showed 11.31 to 14.81 ton DM/ha (average 13.13 ton DM/ha) for diluted and 10.57 to 12.51 ton DM/ha (average 11.50 ton DM/ha) for undiluted cattle slurries, these had a higher dry matter yield than those of no fertilizer (9.21 ton DM/ha). Furthermore, separate application of early spring and summer (SA plots), separate application of early and late spring, and summer (SUA plots) fur undiluted cattle slurries, and whole application of spring (DS plots), separate application of early spring and summer (DSA plots), separate application of early and late spring, and summer (DSUA plots) for diluted cattle slurries were significantly (P<0.05) higher for annual dry matter yield than no fertilizer plots. Plots applied chemical fertilizer with nitrogen (N), phorphorus (P) and potassium (K) had 15.38 ton DM/ha annually, resulted in significantly (P<0.05) higher DM yield than chemical fertilizer containing P and K, and no fertilizer plots. Moreover, average annual DM yield for the chemical fertilizer with P and K was lower than that of cattle slurry applications. The efinciency of DM production for mineral nitrogen of chemical fertilizers was annually average 31.3 kg DM/kg N. In terms of cutting time of tall fescue, it was lowered in the order of 2nd growth followed by 1st and 3rd growth. However, efficiencies of annual DM production of nitrogen for diluted and undiluted cattle slurries were 26.1 and 15.3 kg DM/kg N, respectively, especially, highest in 2nd growth. While, efficiencies of DM production for cattle slurry versus for mineral nitrogen were 48.9 (undiluted) and 83.4% (diluted), respectively. For annual crude protein (CP) contents of tall fescue, aqueous cattle slurry applications showed 9,9 to 11.6%, which were significantly (P<0.05) higher than no fertilization (9.5%) and chemical fertilizer (9.0 to 9.8%), but annual average NDF and ADF contents were lowest in no fertilization. On the contrary, relative feed value (RFV) and total digestible nutrients (TDN) of no fertilizer plots were significantly (P<0.05) higher than the other plots. The application of cattle slurry and their dilution significantly increased yields of crude protein and total digestible nutrients compared with no and/or P and K fertilizers (P<0.05). These trends were much conspicuous in water-diluted cattle slurries applied in the early and late spring and summer, separately (DSUA plots).

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.2
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• pp.45-58
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• 2006

This study was aimed to propose the plan of creating a biotope reflecting an ecological education as well as its function as the habitats of amphibian in Namsan Urban Natural Park in Seoul. There were Cheonil mineral spring area which was located on the southern side of Namsan, wetlands which was already created on the east valley(800$m^2$) and a buffer area of the circumference(1,100$m^2$) as the biotope sites. Major fields of this study include a survey of the staus, a basic plan, a master plan; a survey of this site was focused on topography, water system, existing vegetation, wildbird, amphibian, trail; a detailed plan was focused on flow plan, planting plan, facility plan. Existing vegetation was classified into 8 types; Pinus densiflora forest, Pinus densiflora planted area, Prunus sargentii-Quercus spp. forest, Pinus rigida forest, Robinia pseudoacacia forest, artificial green space, wetlands, south beltway. There were Pinus densiflora planted area and Prunus sargentii-Quercus spp. forest as major vegetations of this site. 14 species and 33 individuals of wildbirds appeared, Rana temporaria ornativentris and Hynobius leechi were investigated in the wetlands.In particular, habitats of amphibian were divided eco-zone, buffer-zone and restore-zone, and habitats and facilities which would be suitable for the characteristics of each space were planned. As a result, environment elements of good habitats including spawn wetlands of amphibian, harbor of amphibian, water plant of wetland, wild shrubs forest, ecological landscape forest, wetland observation trail, fence of wetland protection and ramp by pebble and log were created at the site. The amphibian biotope of Namsan is rated high as an important space for conserving biodiversity. Accordingly, continuous monitoring of this biotope as a urban habitat is required as the environment changes.