• Title/Summary/Keyword: water balance

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Climatic Water Balance Analysis Using NOAA/AVHRR Satellite Images (NOAA/AVHRR 위성영상을 이용한 기후학적 물수지 분석)

  • Kwon, Hyung-Joong;Shin, Sha-Chul;Kim, Seong-Joon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.47 no.1
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    • pp.3-9
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    • 2005
  • The purpose of this study was to analyze the climatic water balance of the Korean peninsula using meteorological data and the evapotranspiration (ET) derived from NOAA/AVHRR, Quantifying water balance components is important to understand the basic hydrology, In this study, a simple method to estimate actual ET was proposed based on a regression approach between NDVI and Morton's actual ET using NOAA/AVHRR data, The Mortons actual ET for land surface conditions was evaluated using a daily meteorological data from 77 weather stations, and the monthly averaged Morton's ETs for each land cover was compared with the monthly NDVIs during the year 2001. According to the climatic water balance analysis, water deficit and surplus distributed maps were created from spatial rainfall, soil moisture, and actual and potential ETs map, The results clearly showed that the temporal and spatial characteristics of dryness and wetness may be detected and mapped based on the wetness index.

Analysis of Wetness/Dryness in Geum River Basin based on Climatic Water Balance (기후학적 물수지에 의한 금강유역의 습윤/건조 상태 분석)

  • Kim, Joo Cheol;Lee, Sang Jin
    • Journal of Korean Society on Water Environment
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    • v.26 no.2
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    • pp.243-251
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    • 2010
  • Evapotranspiration and rainfall-runoff are the major components of hydrological cycle and thereby the changes of them can directly affect the wetness/dryness or runoff characteristics of basins. In this study the wetness/dryness in Geum river basin are classified by dint of cumulative probability density function of monthly moisture index and the long term changes of them are analyzed based on climatic water balance concept. The drought events in Geum river basin are selected through evaluation of monthly moisture index and the various hydrological properties of them are investigated in detail. Also the trends of time-series of climatic water balance components are examined by Seasonal Kendall test and the variability of hydrological cycle in Geum river basin during the recent decade is inquired. It is judged that the results of this study can be contributed to establishment of the counter plan against the future drought events as the fundamental information.

Operation Rule of Irrigation Reservoir (灌漑 貯水池의 利水 管理 方法)

  • Kim, Tae-Cheol;No, Jae-Gyeong;Park, Seung-Gi
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.34 no.1
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    • pp.33-40
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    • 1992
  • Up to now, monthly water balance analysis has been dominantly used for the water resources planning. But, it is more reasonable to explain the variation of spatial and temporal distribution of water by the daily water balance model with daily streamflow data. Since we are recently facing the problems of regional unbalance of water quantity, and of multiuse of irrigation water, and of deterioration of water quality, it is urgently needed to develop the daily water balance model to solve those problems and establish the rational plannings of agricultural water resources. In the circumstances, Daily water Balance(DAWABA) model for irrigation reservoirs was developed and the operation rule of irrigation resorvoir during drought season was established.

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The Effects of Water-Based Exercise on Physiological Cost Index and Balance in Stroke Patients

  • Park, Seung-Kyu;Park, Sam-Heon
    • The Journal of Korean Physical Therapy
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    • v.26 no.6
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    • pp.411-417
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    • 2014
  • Purpose: This study attempts to find the effects of water-based exercise performed on stroke patients in their physiological cost index and static and dynamic balance. Methods: The subjects were 30 stroke patients, who were randomly divided a water-based exercise group and a land-based exercise group, each with 15 patients. Both exercises ware performed 3 day per week, for 40 minutes a day, for a period of eight weeks. Results: The Water-based exercise group showed a decreased physiological cost index compared to the land-based exercise group, with the physiological cost index of the water-based exercise group decreasing, while the land-based exercise group, showing a significant decrease. Water-based exercise increased static and dynamic balance capacity better than land-based group, showing a significant difference and better efficiency of water-based exercise when compared to land-based exercise. Conclusion: From the result of the study, we found that water-based exercise is more effective in improving PCI and static and dynamic balance capacity. Through this study, training in water-based stroke patients could use cardiovascular endurance and buoyancy and the vortex, as an effective treatment that can enhance the growth and voluntary participation in the range of the patient's own movement the thought is, in consideration of the changes in the physiological cost index due to the difference in the ground and water, and should establish a training program that matches the purpose.

Analysis of water balance for pending depth treatment in paddy fields (논 담수심 처리에 따른 관개용수량의 분석)

  • Park, Ki-Jung;Chung, Sang-Ok;Sohn, Seung-Ho
    • Journal of The Korean Society of Agricultural Engineers
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    • v.46 no.4
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    • pp.13-21
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    • 2004
  • The purpose of this study was to investigate tile effects of pending depth treatment on water balance in paddy fields. Field experiment was performed in an experimental farm in Taegu, southern part of Korea during the rice growing season In 2001, 2002 and 2003. Experimental plots were three 8m ${\times}$ 80m rectangular plots. Three pending depth treatments, very shallow, shallow, and deep were used. Daily values of water balance components were measured in the field. The irrigation amounts measured at the experimental plots showed that the very shallow and the shallow ponded plots required smaller amount than the deep ponded plot. The shallow ponded plot saved irrigation water about 17.7% compared with the traditional deep ponded plot in 2001 The very shallow ponded plot saved irrigation water about 25.7% compared with the traditional deep ponded Plot in 2002, The shallow ponded plot saved irrigation water about 18% compared with the deep ponded plot in 2003.

Evapotranspiration Estimation Study Based on Coupled Water-energy Balance Theory in River Basin

  • Xue, Lijun;Kim, JooCheol;Li, Hongyan;Jung, Kwansue
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.146-146
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    • 2018
  • Basin evapotranspiration is the result of water balance and energy balance, which is affected by climate and underlying surface characteristics, the process is complex, and spatial and temporal variability is large, the evapotranspiration estimation of river basin is an important but difficult problem in the field of hydrology, over the years, many scholars devoted to the basin actual evapotranspiration estimation and achieved excellent results. We discuss Budyko coupled water-energy balance theory and evaporation paradox, then use the Fu's equation to estimate actual evapotranspiration yearly in different areas with different dryness. The result shows that Fu's equation has high precision for estimating evapotranspiration yearly in our selected study area, and the estimation result has higher precision in the area with high dryness. Then, we propose an improved formula which can be used to estimate actual evapotranspiration monthly. Furthermore, we found that the parameter in the formula reflects general conditions of underlying surface and it is affected by several factors, at last, we tried to propose the calculation formula. The study indicates that Fu's equation provides a reliable method for evapotranspiration estimation in dry regions as well as semi-humid and semi-arid regions, which has great significance for forecasting river basin water resources and inquiring into ecological water requirement.

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Evapotranspiration and Water Balance in the Basin of Nakdong River (낙동강유역의 증발산량과 물수지)

  • 조희구;이태영
    • Water for future
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    • v.8 no.2
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    • pp.81-92
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    • 1975
  • Calculation of the monthly water balance for Nakdong River basin for the period from 1958 to 1968 is made by determining three components independently: precipitation, runoff and evapotranspiration. The areal precipitation is computed by the Thiessen method using the records of nine meteorological stations in the basin, and the runoff is the flow gauged at Jindong which is located on the most downstream. For the computation of evapotranspiration, the Morton method is adopted because this method is relatively fit best in the calculation of water balance among the Morton, Penman and Thornthwaite methods. The values of Morton evapotransp iration are corrected by the factor of 0.82 in the basin in order to bring the error to zero. The areal evapotranspiration is the arithmetic mean of the Morton estimates at the stations. Mean water balance components in the Nakdong river basin are 1117.0mm, 600.6mm and 516.4m for precipitation, runoff and evapotranspiration respectively. Accordingly, the mean runoff ratio comes out to be 0.54. The smallest values of runoff coefficient are due for Daegu area, while the largest ones are for the southwest of the basin with the higher rainfall and high elevations there. The amount of runoff obtained by both Thornthwaite and Budyko methods for water balance computations indicate 59 and 60 per cent of actual values which are lower than the expected. An attempt is made to find the best reliable rainfall-runoff relation among the four methods proposed by Schreiber, 01'dekop, Budyko and Sellers. The modified equation of Schreiber type for annual runoff coefficient could be obtained with the smallest mean error of 11 per cent.

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Development of a Hydrologic System for Simulating Daily Water Storage in an Estuary Reservoir

  • Noh, Jae-Kyoung
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.45 no.7
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    • pp.1-10
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    • 2003
  • In order to analyze the water supply capacity in an estuary reservoir, a system composed of daily water balance model and daily inflow model was developed. The agricultural water demands to paddy fields, domestic water demands to residential areas, and industrial water demands to industrial complexes were considered in this daily water balance model. Likewise, the outflow volume through sluice gates and inside the water level at the start of the outflow was initially conditioned to simulate estuary reservoir storage. The DAWAST model (Noh, 1991) was selected to simulate daily estuary reservoir inflow, wherein return flows from agricultural, domestic, and industrial water were included to simulate runoff. Using this system, the water supply capacity in the Geum River estuary reservoir was analyzed.

Development of a GIS-Based Basin Water Balance Analysis Model (GIS 기반의 유역물수지 분석모형 개발)

  • Hwang, Eui-Ho;Kim, Kye-Hyun;Park, Jin-Hyeog;Lee, Geun-Sang
    • Journal of the Korean Association of Geographic Information Studies
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    • v.7 no.4
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    • pp.34-45
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    • 2004
  • Existing Semangeum's water balance analysis simplifies whole basin to single basin and achieved volume of effluence that produce by Kajiyama way to foundation. But Semangeum is complicated and various rice-wine strainer supply system. And there is difficulty to apply as elastic when water balance element is changed at free point. Divided to unit possession station for suitable water balance analysis model application to Semangeum in this study. And developed basin water balance model of GIS base that can do details analysis is bite about development and transfer of an appropriation in the budget of basin water resources. Achieved study including abstraction and concept design that use UML (unified modeling language) diagram for details analysis, stream network composition for rice-wine strainer supply system application, preprocessing of GIS base and postprocessing module development, model revision and verification etc. Support of this water balance analysis model is available to establish efficient water resources administration plan through outward flow process analysis of water resources. And support is considered to be possible in more convenient and, reasonable water resources administration way establishment by minimizing manual processing in systematic water resources government official to user and support diversified analysis system.

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