• Title/Summary/Keyword: Evaportanspiration

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Influence on Settlement of Shallow Foundation as a Result of Vegetation and Environmental Changes (기상이변과 식생의 증발산 작용이 얕은기초의 침하에 미치는 영향)

  • Kim, Hong-Taek;Gang, In-Kyu;Park, Min-Yong
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.574-579
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    • 2004
  • In this study, finite difference method used in order to analyze influence on settlement of shallow foundation as a result of vegetation and environmental changes, On boundary conditions to analyze, divided the foundation to clayey silt, changed the amount of evaportanspiration to consider the influence of vegetation, and assumed that the duration of enviromental changes are 180 days to consider the influence of environmental changes. It is expected that this study will do to predicting settlement of shallow foundation as well as to preventing damage of shallow foundation.

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The Estimation of Daily Evapotranspiration in a watershed by the modified Beken's formula (변형 Beken식에 의한 일별 유역 증발산량 추정)

  • Lee, Jae-Myun;Lee, Doo-Hee;Kim, Tai-Cheol
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2003.10a
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    • pp.447-450
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    • 2003
  • It is important to calculate runoff, percolation and evapotranspiration in process hydrological cycle. Especially, a evaportranspiration in watershed has a very important effect on hydrological cycle. In the study, the watershed evapotranspiration was calculated by the water balance and a daily evaportanspiration coefficient(CE) was calculated by the modified Beken's formula.

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Probable Evapotranspiration of Paddy Rice using Dry Day Index

  • 장하우;김성준
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.37 no.E
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    • pp.72-78
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    • 1995
  • To support some knowledge in planning irrigation system, short or long-term irrigation scheduling or determining irrigation reservoir capacity, it is necessary to estimate peak irrigation requirements and seasonal distribution of water demands for various return periods. In this paper Dry Day Index and Probable Evapotranspiration were evaluated to decide seasonal consumptive use of paddy rice for a design year using several decades' daily rainfall data and 5 years'('82~'86) actual evapotranspiration data, respectively. To obtain Dry Day Index that is defined as the number of probable dry days for a given period, Slade unsymmetrical distribution function was adopted. Dry Day Index was analysed for 5 and 10-day intervals. Each of them was evaluated with return periods of 1, 3, 5, 10 and 20 year. Their singnificance was tested by X$^2$ method. Based on these values, the Probable Evaportanspiration, that is the average daily ET both in dry days and rainy days during a given period, was estimated. Crop coefficient was also determined by the modified Penman equation proposed by Doorenbos & Pruitt.

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The CO2 Reduction Potential Calculation through the Urban Park Construction

  • Lee, Eun Yeob;Kang, Myung Soo;Kim, Jong Kon
    • KIEAE Journal
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    • v.14 no.2
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    • pp.87-98
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    • 2014
  • This study is to identify quantitatively the function of carbon dioxide emissions reduction due to temperature and energy reduction according to direct carbon dioxide storage, shade provision, and evaportanspiration of urban park. According to the result of study, landscape tree indicated high carbon dioxide storage effect compare to bush, in which broadleaf tree indicated higher storage function than coniferous tree. It is believed to be the storage of carbon dioxide can be increased by increasing the composition rate of forest plants in the urban park. According to the direct estimation result of carbon dioxide storage in terms of example area, storage of carbon dioxide is estimated to be "seoul a zone" $476,818.8kg{\cdot}CO_2/m^2yr$, "anyang b zone" $186,435.7{\cdot}CO_2/m^2yr$, "daejeon c zone" $262,826{\cdot}CO_2/m^2yr$, "kwangju d zone" $231,657.8{\cdot}CO_2/m^2yr$. The carbon dioxide storage per unit area estimated to be "seoul a zone" $3.4{\cdot}CO_2/m^2yr$, "anyang b zone" $5.0{\cdot}CO_2/m^2yr$, "daejeon c zone" $2.6{\cdot}CO_2/m^2yr$, "kwangju d zone" $5.6{\cdot}CO_2/m^2yr$. The result of indirect carbon dioxide reduction effect estimated to be "seoul a zone" $291,603.4{\cdot}CO_2/m^2yr$, "anyang b zone" $165,462.4{\cdot}CO_2/m^2yr$, "daejeon c zone" $141,719.2{\cdot}CO_2/m^2yr$, "kwangju d zone" $154,803.4{\cdot}CO_2/m^2yr$. Carbon dioxide reduction potential amount through the urban park was increased to 1.6 times to 1.8 times when calculated to the indirect effect.

Application of Heat Balance Model Design of Ventilating and Cooling Greenhouse (온실의 환기 및 냉방 설계를 위한 열평형 모델의 작용)

  • 남상운
    • Journal of Bio-Environment Control
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    • v.9 no.4
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    • pp.201-206
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    • 2000
  • A certain system to overcome high temperature should be introduced for the stable year-round cultivation in greenhouses. There are efficient methods to overcome high temperature such as ventilation system with shading screen, fan and pad system with screen, and fog system with screen. This study was carried out to find a means to determine the capacity of such system. Heat balance equations for each system were established and verified by experimental results. The calculated ventilation rates from heat balance equations showed a good agreement with the measured ones. The evapotranspiration coefficient was the most important parameter affecting the ventilation requirement among input parameter affecting the ventilation requirement among input parameters except weather data. When the evaportanspiration coefficient increased 1%, the ventilation requirement decreased 1.3%. Therefore the data of evapotranspiration coefficient should be accumulated by various experiments, and then design standards and selection guidelines should be provided. The simulation results for same design conditions shown that air exchanges requirement and evaporating water of fan and pad system were 5.1∼7.7% and 6.8∼9.3% larger than those of fog system, respectively.

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Evaluation of Forest Watershed Hydro-Ecology using Measured Data and RHESSys Model -For the Seolmacheon Catchment- (관측자료와 RHESSys 모형을 이용한 산림유역의 생태수문 적용성 평가 -설마천유역을 대상으로-)

  • Shin, Hyung Jin;Park, Min Ji;Kim, Seong Joon
    • Journal of Korea Water Resources Association
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    • v.45 no.12
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    • pp.1293-1307
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    • 2012
  • This study is to evaluate the RHESSys (Regional Hydro-Ecological Simulation System) simulated streamflow (Q), evapotranspiration (ET), soil moisture (SM), gross primary productivity (GPP) and photosynthetic productivity (PSNnet) with the measured data. The RHESSys is a hydro-ecological model designed to simulate integrated water, carbon, and nutrient cycling and transport over spatially variable terrain. A 8.5 $km^2$ Seolma-cheon catchment located in the northwest of South Korea was adopted. The catchment covers 90.0% forest and the dominant soil is sandy loam. The model was calibrated with 2 years (2007-2008) daily Q at the watershed outlet and MODIS (Moderate Resolution Imaging Spectroradiometer) GPP, PSNnet and 3 year (2007~2009) daily ET data measured at flux tower using the eddy-covariance technique. The coefficient of determination ($R^2$) and the Nash-Sutcliffe model efficiency (ME) for Q were 0.74 and 0.63, and the average $R^2$ for ET and GPP were 0.54 and 0.93 respectively. The model was validated with 1 year (2009) Q and GPP. The $R^2$ and the ME for Q were 0.92 and 0.84, the $R^2$ for GPP were 0.93.