• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.1 s.12
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• pp.51-56
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• 2004

In this study, the variation of water quality in Osan stream was investigated through continuous monitoring, and mass balance and metabolism occurred into water body were estimated to set up effective management plan for water quality of small urban stream. From the results of continuos investigation of water quality in Osan stream, the things written as follows must be previously done to improve water quality of main stream. Firstly, it need that effective management plan for tributaries must be set up to improve the water quality in main stream. Secondly, the counter plan for re-eruption of pollutants from sediment in main-stream is required to prevent inner pollution. In this study, we showed that small urban stream can be managed effectively by simple investigation to prevent deterioration of water quality. Therefore continuous monitoring for water quality in stream is important to improve water quality, furthermore matter cycle and mass balance happening in the stream environment must be correctly estimated to make up healthy stream environment.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.516-516
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• 2022

Agricultural reservoirs are critical water resources structures to ensure continuous water supplies for rice cultivation in Korea. Climate change has increased the risk of reservoir failure by exacerbating discrepancies in upstream runoff generation, downstream irrigation water demands, and evaporation losses. In this study, the variations in water balance components of 400 major reservoirs during 1973-2017 were examined to identify the reservoirs with reliable storage capacities and resilience. A conceptual lumped hydrological model was used to transform the incident rainfall into the inflows entering the reservoirs and the paddy water balance model was used to estimate the irrigation water demand. Historical climate data analysis showed a sharp warming gradient during the last 45 years that was particularly evident in the central and southern regions of the country, which were also the main agricultural areas with high reservoir density. We noted a country-wide progressive increase in average annual cumulative rainfall, but the forcing mechanism of the rainfall increment and its spatial-temporal trends were not fully understood. Climate warming resulted in a significant increase in irrigation water demand, while heavy rains increased runoff generation in the reservoir watersheds. Most reservoirs had reliable storage capacities to meet the demands of a 10-year return frequency drought but the resilience of reservoirs gradually declined over time. This suggests that the recovery time of reservoirs from the failure state had increased which also signifies that the duration of the dry season has been prolonged while the wet season has become shorter and/or more intense. The watershed-irrigated area ratio (W-I_ratio) was critical and the results showed that a slight disruption in reservoir water balance under the influence of future climate change would seriously compromise the performance of reservoirs with W-I_ratio< 5.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.1 no.2
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• pp.49-60
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• 2003

The purpose of this study was to evaluate the effect of Halliwick 10 point program on the balance control. Fourteen undergraduate students participated in the experiment, and classified 7 experiment and 7 control group, randomly. Halliwick 10 point program was applied in the experiment group for 4 weeks. Balance index was measured using KAT 2000. Balance index were measured before, during(2 weeks), and after(4 weeks) the training for 4 weeks. 2-way repeated measures ANOVA was used to further distinguish between the groups. The following results were obtained; 1. The total balance index scores from a KAT were significantly decreased after 4 weeks compared with before the training passing of time. However there was no significant difference between experiment and control group. 2. The left and anterior shifting balance index scores from a KAT were significantly decreased after 4 weeks compared with before the training passing of time. However there was no significant difference between experiment and control group. These results lead us to the conclusion that the balance ability of women twenties increase as the water is higher than that of the ground applied Halliwick 10 point program of the water specific therapy province. Therefore, A further direction of this study will be to provide more evidence for Halliwick 10 point program in the water specific therapy.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.99-105
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• 2001

The purpose of this study is to investigate the effects of pending depth treatment on water balance in paddy fields. The pending depth treatments were very shallow, shallow and deep. The experimental plots were three $80m{\times}25m$ rectangular plots. Daily values of rainfall amount, pending depth, irrigation water, drainage water, evapotranspiration, infiltration, and piezometeric head were measured in the field. The pending depth was continuously observered by water level logger during the growing season. The ET was measured in 1m diameter PVC lysimeters. Irrigation water volume was measured by 75m pipe flow meter and the drainage water volume was measured by 25mm and 75mm pipe flow meters and a recording Parshall fulume. PVC pipe piezometers with 12mm diameter were used. The results of the water balance showed that irrigation water of 881.1mm, 735.4mm, and 532.6mm in very shallow, shallow, and deep pending, respectively. The effective rainfall was 182.6mm(44.6%), 254.7mm(62.2%), and 188.6mm(46.0%) in very shallow, shallow, and deep pending, respectively. The results show that the shallow pending depth looks the best of the three treatments.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.2
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• pp.67-74
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• 2002

The purpose of this study was to investigate the effects of ponding depth treatment on water balance in paddy fields. Three ponding depth treatments, very shallow, shallow, and deep were used. The experimental plots were three 80m $\times$ 8m rectangular plots. Daily values of rainfall amount, ponding depth, irrigation water, drainage water, evapotranspiration, and infiltration were measured in the field. The ponding depth was continuously observed by water level logger during the growing season. The ET was measured by 1-m diameter PVC lysimeters. Irrigation water volume was measured by 75 mm pipe flowmeters and the drainage water volume by 75 mm pipe flowmeters and a recording Parshall flume. The results showed that irrigation water depths were 688.9 mm, 513.6 mm, and 624.4 mm in very shallow, shallow, and deep ponding, respectively. The effective rainfall amounts (effective ratio) were 243.7 mm(48.8%), 344.6 mm(68.9%), and 272.9 mm(54.6%) in very shallow, shallow, and deep ponding, respectively. The three treatments did not show any statistical difference in growth and yields. But the shallow depth treatment showed the largest yield.

• Clinical and Experimental Pediatrics
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• v.49 no.5
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• pp.463-469
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• 2006

Sodium is the major cation of the extracellular fluid and the primary determinant of extracellular osmolality. Therefore, hypernatremia causes water movement out of cells, while hyponatremia causes water movement into cells, resulting in cellular shrinkage and cellular swelling, respectively. Serious central nervous system symptoms may complicate both conditions. Since hypernatremia and hyponatremia are accompanied by abnormalities in water balance, it is essential to understand the mechanisms regulating extracellular osmolality and volume as well as the pathophysiology of hypernatremia and hyponatremia, in order to manage both conditions with swiftness and safety.

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.4
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• pp.157-164
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• 2011

Long-term annual water balances are analyzed for two forest catchments located in Gwangneung covered with forests of different types and ages. The water balance trends of the two catchments from 1982 to 2009 are compared to identify the effect of forest growth and thinning on the water balance in a planted coniferous forest catchment. According to the averaged annual precipitation and runoff for the four designated periods from 1982 to 2009, the water balance of the old natural broad-leaved forest catchment (GB) remained relatively unchanged. In contrast, the young planted coniferous forest catchment (GC) showed significant changes in the water balance due to the forest growing and thinning. The results showed that the catchment runoff decreases with increasing tree age whereas the forest thinning results in an increase in catchment runoff. The mean annual runoff from the catchment GC after thinning increased by 1.7 times, compared with the mean annual runoff before forest thinning. The mean annual runoff from the catchment GB was very stable throughout the period. However, such an effect of forest thinning appeared to last only for about 10 year-period, after which the water yield increment in the catchment GC disappeared. It indicates that the proper forest management should be reconsidered at the interval of 10 years to effectively reduce water loss and increase water yield in the planted coniferous forest.

• Water Engineering Research
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• v.6 no.1
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• pp.31-38
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• 2005

Groundwater recharge is defined in an addition of water to groundwater reservoir. Recently, many people have been moving to the Edwards aquifer and urban and agricultural industry have been expending. Hydrologists and water planning managers concern about insufficient groundwater amounts and irrigation water price variability. In this paper, I focus on estimates of local recharge volumes and quantify preferential flow through GIS technique. Chloride Mass Balance (CMB) and hydrochemical components have been widely applied to recharge rate and evaluate flow paths. The CMB method is based on relationship between wet-dry chloride deposition data and Rainfall data. These data are manipulated using ArcGIS. Especially, hydrochemical concentration distribution is good index for groundwater residence times or flow paths such as $[Mg^{2+}]/[Ca^{2+}],[Cl]$ and log$([Ca^{2+}]+[Mg^{2+}])/[Na^+]$. Well information such as hydrological-hydrochemical data are imported into ArcGIS and manipulated by interpolation techniques. For each potentiometric surface and water quality, point data are converted to spatial data through each Kriging and Inverse Distance Weighted (IDW) techniques.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.7
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• pp.57-69
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• 2003

To evaluate nutrient dynamics with different fertilization in paddy field and develop water quality model, mass balance analysis was performed during growing season of 2001-2002 in field experimental plots irrigated with groundwater. As a result of water balance analysis, most of outflow was surface drainage as about half of total outflow and about 500mm was lost by evapotranspiration. The water budget was well balanced. The runoff from paddy field was influenced by rainfall and forced drain. Especially runoff during early cultural periods more depends on the forced drain. As a result of mass balance analysis, most of nutrient was input by fertilization and lost by plant uptake. Significant amount of nitrogen were supplied by precipitation and input from upper paddy field, comprising 12%∼28% of total inflow. Nutrient loading by surface drainage was occurred showing about 15%∼29% for T-N and 6%∼13% for T-P. The response of rice yield with different fertilization was not significant in this study. Water quality model for paddy field developed using Dirac delta function and continuous source was calibrated and validated to surface water quality monitoring data. It demonstrates good agreement between observed and simulated. The nutrient concentration of surface water at paddy field was significantly influenced by fertilization. During early cultural periods when significant amount of fertilizer was applied, surface drainage from paddy field can cause serious water quality problem. Therefore, reducing surface drainage during fertilization period can reduce nutrient loading from paddy fields. Shallow irrigation, raising the weir height in diked rice fields, and minimizing forced surface drainage are suggested to reduce surface drainage outflow.

• Journal of Korea Water Resources Association
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• v.31 no.4
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• pp.503-512
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• 1998

When various elements of water balance are displayed at several points of a river network, the runoff amounts at an estuary especially tidal influenced are affected from the elements. This problem can be solved by a model that can generalize and formulate the elements and simulate daily runoff and water requirement. The WWASS model was built using DIROM for the simulation of daily runoff and water requirement, and the water balance elements were modeled to be balanced at the each control point of river network. The model was calibrated, verified and applied to the watershed for the Saemankeum tidal land reclamation development project. It showed that the results from the streamflow simulation at the Mankyung and Dongjin estuary were acceptable for the design of the Saemankeum estuary reservoir.