• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.327-328
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• 2021

In the manufacturing process of ready-mixed concrete, quantity management directly affects the workability and strength of concrete. Therefore, water quantity is the most important management factor for water quality control of ready-mixed concrete. It can be said that the number of unit water in the mix design, the water quantity due to the surface water contained in the aggregate used, and the water quantity taking into account the concentration of sludge contained in the recycling water when using the recycling water are factors that affect the quantity management of ready-mixed concrete. In this study, as a stable quality control method of ready-mixed concrete, a quantity management method by aggregate surface water and a sludge concentration management method according to the use of recycling water were proposed. Thus, we tried to suggest an efficient quantity management method for stabilizing the quality of ready-mixed concrete.

• Journal of Korean Society on Water Environment
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• v.27 no.6
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• pp.932-937
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• 2011

Main objectives of this paper were; firstly, to explain impacts of suspended solid in the water body on the relationship between water quantity and water quality; secondly, study on the inter-relationship between organic materials, nutrients, pathogens, and suspended solids considering eco-friendly water resources. Relationship between water quality and water quantity is not easy to understand as it includes physicochemical-biological reactions and diffuse pollutions. Especially, suspended solid makes water resource management difficult. Eroded soil in the upper land transported to the downstream by water flows carrying biological and physicochemical information and sedimented in the downstream. As sediment scoured under high flow condition and environmental change, suspended solid and sediment should be emphasized for understanding the inter-relationship between water quality and water quantity. Knowledge gaps between known monitored data and management of suspended solid were identified as well for future study.

• Journal of Korean Society on Water Environment
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• v.23 no.3
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• pp.385-390
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• 2007

Reliable flow measurement for dry season is very important to set up the in-stream flow exactly and total maximum daily load control program in the basin. Especially, in the points which tidal current effects are dominant because reliability of the low measurement decrease. The reliable measuring methods are needed. In this study, we analysis the water surface elevation difference of water surface elevation. Quantity relationship to consider tidal currents in these regions. It is known that tidal current effects from Nakdong river barrage are dominant in Samrangjin measuring station. We developed multiple regression equation with water surface elevation, quantity, and difference of water surface elevation and compared these results water measured rating curve. All of these regression equation including linear regression equation and log regression equation fits better measured data them existing water surface elevation quantity line and Among three equations, the log regression equation is best to represent the measured the rating curve in Samrangjin point. The log regression equation is useful method to obtain the quantity in the regions which tidal currents are dominant.

• Journal of Industrial Technology
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• v.21 no.B
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• pp.233-240
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• 2001

This research was conducted with the aim of efficiently managing large scale of rivers such like Songyang-river through predicting water quality change with analyzing the characteristics of the flowing in nutrients and pollutants. The main result will be used as basic data for effectively operating reservoirs through controling water quality and quantity. The relationship between quantity of flow and water quality was analyzed and pollution loading into the basin was estimated. Three areas of Soyang-river upstream and one area of Suip-cheon in Yanggu-gun were selected as research sites. Flow and water quality were measured simultaneously. The relation between quantity of discharge and pollution concentration and between quantity of discharge and pollution loading were analyzed by statistical method, respectively. We provided a rating curve through measuring quantity of discharge(collecting quantity of discharge) and pollutograph and pollution loading curve through water quality data. Also, we analyzed the correlation between quantity of discharge per unit area and pollution loading per unit area in each basin. As resurt of this research, Buk-cheon spot revealed an excellent first grade water quality for the items including $BOD_5$, DO, and SS. The correlation coefficient between Buk-cheon spot's quantity of discharge and pollution loading was 0.896~0.996, showing the validity of analysis applying correlation curve formula of quantity of discharge and pollution loading in the same spot. Also, pollution loading per unit area of the items including $BOD_5$, COD, DO, SS, T-N, T-P increased as the area of basins get increased following the sequence of Buk-cheon, Suip-cheon, Naelin-cheon spots.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.3
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• pp.279-290
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• 2004

Sludge quantity has increased at "A"water treatment plant due to deterioration of raw water quality and GAC installation. Increased sludge resulted in overloading on sludge handling facilities. The object of this study is to survey sludge quantity and capacity of sludge handling facilities at "A"water treatment plant. Measured quantity of sedimentation sludge considerably exceeded the design capacity of sludge holding basin. Sludge holding basin was properly designed, but low concentration of sludge discharged from sedimentation basin caused production of large volume of the sludge. Timer operated control system for sludge withdrawal unit and leakage through a control valve were suspected to cause the low concentration. Augmentation of the control system by a turbidity meter and addition of a new control valve successfully reduced the sludge volume enough to satisfy the design capacity of sludge holding basin. Unlike sedimentation sludge, measured quantity of washwater was considerably less than the design capacity of washwater basin because it was over-designed.

• Journal of Wetlands Research
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• v.19 no.4
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• pp.491-500
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• 2017

Stream water quantity is the most basic, fundamental and important element for stream water quality and for conservation of ecological environment. This study aims to analyze causes of changes in stream water quantity based on the percentage of impervious surface area (%ISA) in urban streams of Gyeonggi-do, and also to present a method to secure water quantity of urban streams in Gyeonggi-do and data to be applied to River Management Policy. For this purpose, the Anyangcheon watershed, the Tancheon watershed, and the Osancheon watershed were selected as samples of the urban streams. In addition, the stream water quantity and the changes in stream water quality which were based on the amount of ISA, and methods to directly and indirectly secure stream water quantity were investigated. The results are as follows. The amounts of ISA of the Anyangcheon watershed, of the Tancheon watershed, and of the Osancheon watershed showed a 5.32%, 6.32%, and 7.22% increase, respectively, from 2014 which was approximately 10 years ago. The runoff coefficient generally increased as the amount of ISA was increased. Water reuse quantity of stream in the Tanchon watershed had a positive effect on securing stream water quantity, but both in the Anyangcheon watershed and in the Osancheon watershed, it did not have a positive effect on that. However, water reuse quantity of stream improved the water quality of each stream.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.265-268
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• 2002

The ground water regime analysis method, numerical analysis method, water budget method, and baseflow analysis method have been used for estimating ground water recharged quantity. This study, adapting water budget concept of unsaturated zone, and saturated zone of the DAWAST model, proposed a new method to estimate ground water recharged quantity.

• Environmental and Resource Economics Review
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• v.9 no.2
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• pp.311-332
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• 2000

The main aim of this paper is to estimate the change in the quantity demanded of public water when the economic factors such as income and water price are changed. The privious methods to estimate the quantity of public water demanded has been usually based on the LPCD(liter per capita per day). Implicitly, this method regards the price of water as given. If the water price and income elasticities of water demand are estimated using the time-series and pooled data analysis. In the second step, the quantity demanded of public water are forecasted using the estimated elasticities. The results show that we can reduce the quantity demanded of residential water considerably when the water price is changed.

• Journal of Environmental Science International
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• v.13 no.3
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• pp.197-204
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• 2004

In this study analyzed the reliability indices against the water supply ability of Andong dam. The water supply analysis of Andong dam used the HEC-5 model. So Andong dam simulated planed water-supply capacity of Andong dam as increase and decrease +5% ～ -5% of water supply quantity. Water-supply capacity of Andong dam estimated, deficit occurrence, deficit quantity, deficit period. As the results estimated reliability(occurrence based, time based, quantity based) and resiliency vulnerability and with water supply capacity evaluation indices of Andong dam. Also reliability(occurrence based, time based, quantity based), resiliency, vulnerability and resiliency indices are estimated to evaluated the performance of water supply on Andong dam, and their relationships are evaluated.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.3
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• pp.1-7
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• 2013

The dam plan quantity of constructive and water supply quantity of present time are showing a difference with change in climate and augmentation of water demand for multipurpose dams in Nakdong river basin. But revaluates a water supply ability the method or the process is official for is not taking a position, so actual condition applies the plan quantity of dam constructive. Considers various situation of actual multipurpose dam from research sees consequently and in K-WEAP is an integrated water resources evaluation plan model applies as water permit availability multipurpose dam, currently water permit availability comparison, analyzed. In this study, the natural daily flow data and apply the dimensions of the reservoir, and for more than 30 years of the long-term water balance analysis conducted by Date Nakdong river basin can supply reservoirs are large quantity of permits available is presented.