• Title/Summary/Keyword: water

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Characteristics of Water Temperature Inversion Observed in a Region West of Jeju Island in April 2015 (2015년 4월에 제주 서부해역에서 발생한 수온역전층 특성)

  • Kim, Seong Hyeon
    • Ocean and Polar Research
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    • v.42 no.2
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    • pp.97-113
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    • 2020
  • In-situ observations were carried out in April 2015 to investigate the occurrence of water temperature inversion in a region west of Jeju Island. Analysis of in-situ in the western part of Jeju island showed that cold water moved to the southeast from the surface to the middle layer and warm water moved from the middle to the lower layer of the northwest direction. The water temperature inversion occurred at 84 stations (63.1%) out of 133 stations. At the boundary of the water temperature inversion layer, it was formed in the middle layer and disappeared. In the strongly appearing, it started from the middle layer to the lower layer. The shape of the water temperature inversion layer was different. As a result of horizontal water temperature slope analysis of the water temperature inversion zone, maximum 0.23℃/km was obtained and the mean was 0.06℃/km. The role of water temperature inversion as an indicator to determine the formation of water front. As a result of the water mass analysis, Jeju Warm Current Water and Tsushima Warm Current Water of high temperature and high salt intruded from the middle to the bottom. In the middle layer occurred as the Yellow Sea Cold Water of low water temperature and low salinity expanded.

The Monthly Water Supply Reliability Indexes in the Parallel Reservoir System

  • Park, Ki-Bum;Kim, Sung-Won;Lee, Yeong-Hwa
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.1612-1615
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    • 2009
  • Water supply reliability indexes (WSRI) is estimated for assessment of water supply capacity in the downstream for parallel reservoir system in Nakdong River, South Korea, using allocation rule (AR) according to the water supply capacity of each reservoir and the characteristic of parallel reservoir system. The result of the analyzing parallel reservoir system for Andong and Imha reservoir in Nakdong River does not include evidences available enough to decide whether the results of water supply analysis are excellent in the current reliability evaluation or not. However, AR (C) shows a good result in the water supply capacity for each reservoir based on the connected operation system and the total water supply capacity at the control point of downstream by the average water supply capacity and possible range of water supply capacity suggested by this study. The average water supply capacity is analyzed by the reliability of monthly average water supply capacity. Furthermore, the possible range of water supply capacity is estimated by the standard deviation when water deficit occurs. Therefore, AR (C) is useful to establish and estimate the planning water supply capacity according to the monthly water supply condition and the possible range of water supply capacity when the water supply capacity deficit occurs, South Korea.

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A study of physical and chemical properties of internal accumulated material in water mains (상수관로 내부 오염물질의 물리화학적 특성 분석)

  • Bae, Cheol-Ho;Choi, Doo-Yong;Lee, Doo-Jin;Kim, Do-Hwan
    • Journal of Korean Society of Water and Wastewater
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    • v.28 no.5
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    • pp.589-600
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    • 2014
  • Tuberculation and slime accumulated in water mains play an important role in modifying water quality of drinking water. Therefore, in this study, it was investigated that what materials were accumulated, and what components were included in the tuberculation and slime of water mains. The Various tuberculation and slime sample were collected from the 12 water mains to analyze their physical and chemical properties and crystal structure. As a analysis method, VSS(Volatile suspended solid), SEM(scanning electron microscope), EDS(Energy Dispersive X-ray spectroscope), ICP(Inductively Coupled Plasma Mass Spectrometer) and XRD(X-Ray Diffractomete) were used. The results of analysis on the samples, the representative materials were verified such as iron corrosion products, the fine sand particles generated during backwash, fine particles of activated carbon, aluminum used in coagulation process, and manganese included in raw water.

Current status of Jeju special self-governing province's water infrastructure and direction for improvement (제주특별자치도 물인프라 현황 및 개선방향)

  • Kim, Jinkeun
    • Journal of Korean Society of Water and Wastewater
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    • v.35 no.6
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    • pp.497-505
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    • 2021
  • This paper investigates the current status of Jeju special self-governing province (JSSGP)'s water infrastructure and recommends directions for improvement. JSSGP relies on groundwater for most of its water resources. Recently, water usage has been steadily increasing due to the increase of residents and tourists while the quality of groundwater has been steadily worsening. Deterioration in water quality of groundwater can be seen through the increase in concentration of nitrate nitrogen and microorganisms. To overcome such problems, water consumption must be reduced by water demand management in all fields including residential and agricultural water use. The quality of water resources should be preserved through the management of pollutants. For efficient management of water resources, great efforts should be made to reduce the leakage rates in household and agricultural water, which is currently at the highest level in the country. Furthermore, diversification of water intake sources other than groundwater is needed, especially for agricultural water supply. For water and sewerage facilities, compliance with drinking water quality standards and discharge water quality standards must be achieved through the optimization of operation management. This process requires recruiting professionals, improving existing workers' expertise, and improving facilities.

Apple Water-Footprint Calculation and Water Risk Action (사과의 지역별 물발자국 비교와 물 리스크 대응 -충주와 거창 지역을 중심으로-)

  • Oh, Young-Jin;Park, Seog-Ha;Kim, Hong-Jae;Kim, Chesoong
    • Journal of the Korea Safety Management & Science
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    • v.15 no.3
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    • pp.113-125
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    • 2013
  • According to 2012 OECD environmental report, Korea was ranked as the first country of water stress. Water footprint is a method to calculate water usage during the life cycle of a product from material procurement through production to disposal to recycle and to quantify the load to water resources. In water footprint calculation, water consumption unit is used. Agricultural water use is over 48% so it is urgent to mange that area Korea needs to spread the discussion about water footprint as quickly as possible, for the study to prevent social and environmental problems due to water shortage. This paper, through water footprint calculation and comparison in Chungju and Geochang areas, looks to counter measures for water risk, targeting domestically-produced apple.

Contributions to the Impaired Water Bodies by Hydrologic Conditions for the Management of Total Maximum Daily Loads (수질오염총량관리 목표수질 초과지역에 대한 유황별 초과기여도 분석)

  • Park, Jun Dae;Oh, Seung Young
    • Journal of Korean Society on Water Environment
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    • v.28 no.4
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    • pp.574-581
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    • 2012
  • It is important to analyze the status of water quality with relation to the stream flow to attain water quality goal more effectively in the unit watersheds for the management of Total Maximum Daily Loads (TMDLs). This study developed a flow duration-water quality distribution graph to figure out water quality appearances on the flow variation and analyzed contributions of water quality observations to the impaired water bodies quantitatively by hydrologic conditions. Factors relating to water quality variation can be analyzed more precisely and assessed on the base of quantified contributions. It is considered that this approach could be utilized to establish a more effective plan for the water quality improvement including the prioritization of pollution reduction options.

The State of Water Resources in the Philippines

  • Rubio, Christabel Jane P.;Jeong, Sang-Man;Lee, Joo-Heon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2008.05a
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    • pp.82-91
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    • 2008
  • This paper sought to provide information regarding the water resources in the Philippines, focusing on the issues of water quality, status of water use and water scarcity, and other threats to water availability. Although the country has sufficient amount of water resources, it was found out that water availability is still threatened by some major water resources problems: increasing water demand due to drastic growth in population, water resources pollution, droughts and flooding and weak institutional framework to address these problems. Water quality problems include increasing groundwater and surface water pollution. Moreover, drought and flooding have also increased damages in recent years due to deteriorating watersheds and high economic and population growth. In relation to these, the Government enacted national laws to define and deal with water control and quality management. The objective of this research was to present and evaluate current conditions and issues on Philippine water resources.

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Environmentally Assisted Cracking of Alloys at Temperatures near and above the Critical Temperature of Water

  • Watanabe, Yutaka
    • Corrosion Science and Technology
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    • v.7 no.4
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    • pp.237-242
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    • 2008
  • Physical properties of water, such as dielectric constant and ionic product, significantly vary with the density of water. In the supercritical conditions, since density of water widely varies with pressure, pressure has a strong influence on physical properties of water. Dielectric constant represents a character of water as a solvent, which determines solubility of an inorganic compound including metal oxides. Dissociation equilibrium of an acid is also strongly dependent on water density. Dissociation constant of acid rises with increased density of water, resulting in drop of pH. Density of water and the density-related physical properties of water, therefore, are the major governing factors of corrosion and environmentally assisted cracking of metals in supercritical aqueous solutions. This paper discusses importance of "physical properties of water" in understanding corrosion and cracking behavior of alloys in supercritical water environments, based on experimental data and estimated solubility of metal oxides. It has been pointed out that the water density can have significant effects on stress corrosion cracking (SCC) susceptibility of metals in supercritical water, when dissolution of metal plays the key role in the cracking phenomena.

A Basic Study for the Variation of Nodal Demands According to the Low Pressure in Water Distribution Systems (배수관망내 수압부족시 절점수요량의 변화에 대한 기초적 고찰)

  • Hyun, In-Hwan;Lee, Sang-Mok;Kim, Young-Hwan;Ahn, Yong-Ho
    • Journal of Korean Society of Water and Wastewater
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    • v.16 no.6
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    • pp.726-732
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    • 2002
  • Pressure drop could happen in the water distribution systems due to pipe breaks or maintenance. The pressure drop causes the water service shutdown and nodal water demands should be reduced in some areas. The conventional analysis method of water distribution systems can not consider the change of nodal water demands caused by these pressure drops. This study is to investigate the variation of nodal water demands according to the nodal water pressure and its effect on the analysis of water distribution systems. For these purpose, one real water service district was selected as a study area. As a result, nodal water demand patterns according to the water pressure could be suggested. Also, we could confirm that the suggested new analysis method for the water distribution systems which considering water pressure drops could be more reliable than the conventional method.