• Journal of Korean Society of Water and Wastewater
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• v.25 no.1
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• pp.7-14
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• 2011

This study was motivated by the purpose of improving the O-Index, currently used to quantify water tasty. The authors first develop the M-Index after normalizing Ca, K, and $SiO_{2}$ concentrations in the spring water, in that the concentrations are subject to their log-normal distributions. The M-Index is then compared with the O-Index based on the results of sensory tests, revealing that sensory tests are correlated with the M-Index much more than the O-Index. Furthermore, the developed index is applied to evaluate water sampled from 53 springs in Korea. It is concluded that water, sampled from five most famous springs, has high values in M-Index. In addition, water, collected from springs that are relatively accessible, contains low values, and thus is expected not to tasty good.

• Journal of Environmental Health Sciences
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• v.42 no.4
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• pp.274-279
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• 2016

Objectives: We investigated bacterial diversity in the Han River water resource protection area in order to provide basic microbiological information on the drinking water safety of the Seoul metropolitan region. Methods: Samples were collected in the spring and winter, but not during the rainy season. Pyrosequencing, gene amplification, and extraction of nucleic acids were employed in this study. Results: In total, 57 and 48 operational taxonomic units were respectively analyzed in samples collected during spring and winter. Proteobacteria were predominant in all samples. The samples contained phylogenetically diverse bacterial communities, with eleven major phyla and 36 genera. Cyanobacteria were predominant in the spring samples, but not in the winter samples. The predominant species in the samples collected during both seasons belonged to the genus Aquamicrobium and Bradyrhizobium. Moreover, no pathogenic bacteria were detected in the samples. Conclusion: Proteobacteria were predominant in the samples from the Han River water source protection area. Cyanobacteria were more predominant in the spring samples than in the winter samples, but Aquamicrobium and Bradyrhizobium were predominant in both sampling seasons.

• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.134-134
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• 2010

Sea ices at the Tatarskiy Straitin the East/Japan Sea appear from November to April. Cold and fresh water, melted from the sea ices, may contain nutrients which are indispensable to spring bloom of phytoplankton and may provide a preferable condition to the spring bloom through changes in vertical structure of water column and stratification. Relation between the spring bloom along the Primorye coast and sea ices in the Tatarskiy Strait were investigated using multi-satellite multi-sensor data; ten-year SeaWiFS chlorophyll-a concentration data and PAR data, sea surface temperatures from NOAA/AVHRR, sea ice concentration and near-surface wind speed data from DMSP/SSMI, near-surface wind vectors from QuikSCAT, and others. We provided evidences of southwestward flowing cold water masses from sea ice and its relation of chlorophyll-a concentration. This study showed that year-to-year variations of chlorophyll-a concentration in spring were positively correlated with those of sea ice concentrations at the Tatarskiy Strait.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.218-218
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• 2019

Jeju island has an area of $1,810km^2$ and is considered the largest island in South Korea. In Jeju Island the average annual precipitation is 1,957mm. About 54% of precipitation is estimated to be lost due to evapo-transpiration and direct runoff, and the remainder is recharged. Historically springs and puddles were the island's primary sources of water. However, after 1970 all sectors, including the urban and industrial sectors depended solely on groundwater as their water resource. As vast amount of water is being recharged the Island has many springs, especially near the coastlines. Historlcally, spring of Jeju Island formed village and make it possible to continue a life. Also it produces many values such as the spring related story, culture, tourism and ecosystems. Especially, the naturally rare phenomenon that about 900 springs appear over the whole area of Jeju Island makes it possible to call it as a natural heritage. As a result of this most springs have either been destroyed or been in the state of neglect. In some cases it has been observed that springs were preserved by nature, however majority of the cases saw springs losing their own nature as a result of abandonment. It was recorded that there were 911 springs in Jeju Island with most of them being distributed along the coast, which consequently increases their susceptibility to seawater intrusion. The objective of this study is therefore to analyze Eco-cultural and Engineering characteristics about springs in the island, highlighting its past utilization and reestablishing its potential as a source of spring.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.40-45
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• 2007

Water regulators in New Zealand have recognised the need to adapt water allocation regimes and water permit conditions to reflect the likelihood of lower catchment yield on the east coast from 2030 due to climate change. Water management mechanisms to protect the environment and maintain the reliability of other water users are currently being applied or assessed in Marlborough province. These include seasonal water quota based on spring aquifer status, linking water use to environmental triggers to avoid seawater intrusion or spring depletion; and redefining water permit entitlements to account for recharge variability.

• Journal of the Geological Society of Korea
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• v.54 no.5
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• pp.529-544
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• 2018

Dongrae hot spring belongs to the residual magma type and has a long history of bathing since the Silla dynasty in Korea. Due to long development of hot spring water, it is expected that the amount of hot spring water in Dongrae hot spring has been changed. In this study, long-trem water level data of Dongrae hot spring were examined for recognizing the change of the hot spring. By the fluctuation analysis of the hot spring water level from January 1992 to July 2018, the maximum and minimum annual drawdowns of no. 27 well were 137.70 and 71.60 meters, respectively, with an average drawdown of 103.39 m. On the other hand, the maximum and minimum annual drawdowns of no. 29 well were 137.80 and 71.70 meters, with an average drawdown of 103.49 m. Besides, drawdown rate became bigger in recent years. As a result of analyzing autocorrelation of the two wells, the correlation coefficient ranged from 0.919 to 0.991, showing seasonal groundwater level fluctuation. The cross correlation analysis between water level and precipitation as well as water level and hot spring discharge resulted in the correlation coefficients of -0.280 ~ 0.256 and 0.428 ~ 0.553, respectively. Therefore, using Dongnae hot-spring water level data from 1992 to 2018, the Mann-Kendall test and Sen's test showed that the continuous decline of water level was mainly caused by the pumping of the hot spring water among various reasons.

• Journal of Soil and Groundwater Environment
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• v.13 no.1
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• pp.1-12
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• 2008

The purpose of this study is to characterize the hydrogeochemical characteristics of hot spring waters and to interpret the source of noble gases and the geochemical environment of the hot spring waters distributed along the eastern area of the Korean peninsula. For this purpose, We carried out the chemical, stable isotopic and noble gas isotopic analyses for eleven hot spring water and fourteen hot spring gas samples collected from six hot spring sites. The hot spring waters except the Osaek hot spring water show the pH range of 7.0 to 9.1. However, the Osaek $CO_2$-rich hot spring water shows a weak acid of pH 5.7. The temperature of hot spring waters in the study area ranges from $25.7^{\circ}C$ to $68.3^{\circ}C$. Electrical conductivity of hot spring waters varies widely from 202 to $7,130{\mu}S/cm$. High electrical conductivity (av., $3,890{\mu}S/sm$) by high Na and Cl contents of the Haeundae and the Dongrae hot spring waters indicates that the hot spring waters were mixed with seawater in the subsurface thermal system. The type of hot springs in the viewpoint of dissolved components can be grouped into three types: (1) alkaline Na-$HCO_3$ type including sulfur gas of the Osaek, Baekam, Dukgu and Chuksan hot springs, and (2) saline Na-Cl type of the Haeundae and Dongrae hot springs, and (3) weak acid $CO_2$-rich Na-$HCO_3$ type of Osaek hot spring. Tritium ratios of the Haeundae and the Dongrae hot springs indicate different residence time in their aquifers of older water of $0.0{\sim}0.3$ TU and younger water of $5.9{\sim}8.8$ TU. The ${\delta}^{18}O$ and ${\delta}D$ values of hot spring waters indicate that they originate from the meteoric water, and that the values also reflect a latitude effect according to their locations. $^3He/^4He$ ratios of the hot spring waters except Osaek $CO_2$-rich hot spring water range from $0.1{\times}10^{-6}$ to $1.1{\times}10^{-6}$ which are plotted above the mixing line between air and crustal components. It means that the He gas in hot spring waters was originated mainly from atmosphere and crust sources, and partly from mantle sources. The Osaek $CO_2$-rich hot spring water shows $3.3{\times}10^{-6}$ in $^3He/^4He$ ratio that is 2.4 times higher than those of atmosphere. It provides clearly a helium source from the deep mantle. $^{40}Ar/^{36}Ar$ ratios of hot spring water are in the range of an atmosphere source.

• Economic and Environmental Geology
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• v.41 no.1
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• pp.15-32
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• 2008

The hydrochemical and isotopic (stable isotopes and noble gas isotopes) analyses for hot spring waters, cold groundwaters and surface water samples from the Seokmodo hot spring area of the Ganghwa province were carried out to characterize the hydrogeochemical characteristics of thermal waters and to interpret the source of thermal water and noble gases and the geochemical evolution of hot spring waters in the Seokmodo geothermal system. The hot spring waters and groundwaters show a weakly acidic condition with the pH values ranging from 6.42 to 6.77 and 6.01 to 7.71 respectively. The outflow temperature of the Seokmodo hot spring waters ranges from $43.3^{\circ}C\;to\;68.6^{\circ}C$. Relatively high values of the electrical conductivities which fall between 60,200 and $84,300{\mu}S/cm$ indicate that the hot spring waters were mixed with seawater in the subsurface geothermal system. The chemical compositions of the Seokmodo hot spring waters are characterized by Na-Ca-Cl water type. On the other hand, cold groundwaters and surface waters can be grouped into three types such as the Na(Ca)-$HCO_3$, Na(Ca)-$SO_4$ and Ca-$HCO_3$ types. The ${\delta}^{18}O\;and\;{\delta}D$ values of hot spring waters vary from -4.41 to -4.47%o and -32.0 to -33.5%o, respectively. Cold groundwaters range from -7.07 to -8.55%o in ${\delta}^{18}O$ and from -50.24 to -59.6%o in ${\delta}D$. The oxygen and hydrogen isotopic data indicate that the hot spring waters were originated from the local meteoric water source. The enrichments of heavy isotopes ($^{18}O\;and\;^2H$) in the Seokmodo hot spring waters imply that the thermal water was derived from the diffusion Bone between fresh and salt waters. The ${\delta}^{34}S$ values ranging from 23.1 to 23.5%o of dissolved sulfate are very close to the value of sea water sulfate of ${\delta}^{34}$S=20.2%o in this area, indicating the origin of sulfate in hot springs from sea water. The $^3H/^4He$ ratio of hot spring waters varies from $1.243{\times}10^{-6}\;to\;1.299{\times}10^{-6}cm^3STP/g$, which suggests that He gas in hot spring waters was partly originated from a mantle source. Argon isotopic ratio $(^{40}Ar/^{36}Ar=298{\times}10^{-6}cm^3STP/g)$ in hot spring waters corresponds to the atmospheric value.

• Journal of the Korean Chemical Society
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• v.44 no.3
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• pp.220-228
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• 2000

This study deals with the water qualities of Dalgi mineral spring in Cheongsong district.Water samples which were taken from upper, middle and bottorn spring sites were tested for twenty eight important water quality items including minerals, essential and/or toxic trace elements, and the analytical items to affect the taste of mineral water, seasonally from May 1999 to February 2000 The results obtained wereas follows:Each spring site showed much difference in major items. Bottom spring water showed higher value of Mg and Na than others. Middle spring water showed the highest value in all of the items except Mg and Na. The concentration of Hardness, Fe and Mn in mineral water were over than the normal standard for drinking water, but these items are not specified for the mineral water. As, Cd, $Cr^{6+}$ and Hg were not found and Pb was found ln trace level. All of the items proved nearly constant during the four seasons except water temperature. The contribution of mineral water to the nutrition of human was calculated in order to investigate the health effect of drinking water on the bases of Required Daily Allowance,one liter of water drinking and the mineral concentration of the bottom spring. The percentage of consumable minerals of Ca, Mg, Na, K, Mn,Zn and Fe were 35.05,36.43,5.88∼10.63,0.19∼0.57,21.86∼43.72,0.65, and 95.l respectively. This means Dalgl mineral water is pIenty of iron mineral. The K and O indexes of mineraI water appeared to be good for healthy and delicious water.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.7-12
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• 2004

A lifetime prediction of holddown spring screw in nuclear fuel assembly was performed using fracture mechanics approach. The spring screw was designed such that it was capable of sustaining the loads imposed by the initial tensile preload and operational loads. In order to investigate the cause of failure and to predict the stress corrosion cracking life of the screw, a stress analysis of the top nozzle spring assembly was done using finite element analysis. The elastic-plastic finite element analysis showed that the local stresses at the critical regions of head-shank fillet and thread root significantly exceeded than the yield strength of the screw material, resulting in local plastic deformation. Normalized stress intensity factors for PWSCC life prediction was proposed. Primary water stress corrosion cracking life of the Inconel 600 screw was predicted by using integration of the Scott model and resulted in 1.78 years, which was fairly close to the actual service life of the holddown spring screw.