Estimation of Crop Coefficients and Evapotranspiration by Meteorological Parameters in a Rain-fed Paddy Rice Field, Cassava and Teak Plantations in Thailand

ペデラーム, アタロッド; 正敏, 青木; 大輔, 小森; 朋靖, 石田; 一成, 福村; サマーキー, ブーンヤワット; ピヤホン, トンディノック; 将納, 横家; ソムニミトル, パンクンガム; ティワー, パーコークトム

doi:10.2480/agrmet.62.93

Cited by 21 publications

(15 citation statements)

References 6 publications

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“…Increase in water yields are attributed by large reduction in ET during dry season from the surface compared to current croplands surface. These results agree with Attarod (2006) that ET of paddy fields in Northeast are lowest in January and peak in the mid growing season in September 16) . Scenario 5 represents a promotion of biofuel production when entire farmland is cleared to produce sugarcane, without considering amount of yields.…”

Section: (2) Hydrologic Impacts On Land Use Changesupporting

confidence: 91%

Impacts of Land Cover Changes on Hydrologic Responses: A Case Study of Chi River Basin, Thailand

Homdee

Pongput

Kanae

2011

J. JSCE

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Land use and land cover (LULC) have been continuously changing, through human activities, leading to variations in hydrological cycle. In this study, we applied SWAT model to investigate potential impacts of LULC on water budget of the Chi river basin in Thailand. Five plausible scenarios of land use change were evaluated, including an conversion of forested area, expansion of farmland, switching of rice paddy fields to energy crops and two scenarios involving conversion of farmland to rice and sugarcane plantation. The results indicated that different land use scenarios contributed to various effects in annual and seasonal water yield and evapotranspiration (ET). Conversion of forested area and farmland showed slightly small changes on water flows and ET. Substitution of paddy fields by sugarcane plantation showed clearly reduced water flows and increased ET by almost 5.0% in dry season. Particularly, in case of expansion of rice paddy fields to farmland, small changes occur on annual flow and ET but more significant effect occur on seasonal flows. The results showed decrease in ET by nearly 12.0%, leading to increase of water yield by up to 5.1% during dry season. Finally, conversion of farmland to sugarcane plantation for biofuel production showed significant effect on seasonal ET, mainly decreasing in dry season by 4.5 % but small changes were detected on water yields.

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Section: (2) Hydrologic Impacts On Land Use Changesupporting

confidence: 91%

Impacts of Land Cover Changes on Hydrologic Responses: A Case Study of Chi River Basin, Thailand

Homdee

Pongput

Kanae

2011

J. JSCE

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“…Both FH2O and FCO2 are closely related to rice production (Attarod et al, 2005). The Bowen ratio technique is a micrometeorological method to quantify crop water use (Mo and Liu, 2001;Shen et al, 2004;Attarod et al, 2006) and it is relatively inexpensive compared with other micrometeorological techniques (Casa, 2000). However, little has been done to determine water consumption by relating FH2O to a unit amount of FCO2 per unit of land area.…”

Section: Introductionmentioning

confidence: 99%

CO2 and H2O Fluxes Ratio in Paddy Fields of Thailand and Japan

Pakoktom

Aoki

Kasemsap

et al. 2009

Hydrological Research Letters

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Abstract:Measurements of CO2 flux (FCO2 ) and H2 O flux (FH2O) were carried out on paddy fields of Thailand and Japan during the 2004, 2005 and 2006 growing seasons using the Bowen ratio technique. The objective was to determine the water resource requirement to achieve a certain amount of CO2 assimilation per land area and analyze the ratio between FCO2 and FH2 O (CWFR = FCO2/FH2O). The relationship between FCO2 and FH2O was investigated using regression analysis in 4 growing stages. Relatively high correlations (r 2 = 0.56 0.96, p < 0.01) between FCO2 and FH2O were found when data were grouped by growing stage. Using daytime average data, there was high correlation (r 2 = 0.61 0.94, p < 0.01) between daytime average CWFR (CWFRd) and daytime average vapor pressure deficit (VPDd) in paddy fields of Japan and Thailand for each growing stage. Pooled data from Thailand and Japan showed high correlations (r 2 = 0.61 0.94, p < 0.01) between CWFRd and VPDd for each growing stage. The developed regression equation was tested using an independent published dataset, and it was found that the estimation error was only 2.7%. The regression equations will be useful for estimating CWFRd by only VPDd and accordingly for assessing the water resource requirement. KEYWORDS carbon dioxide flux; carbon dioxide flux and water vapour flux ratio; paddy rice field; vapour pressure deficit; water vapour flux.

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“…TUAT experimental farm provided a uniform long-fetch location for measurement of AET which was more than 400 m (Attarod et al 2006).…”

Section: Methodsmentioning

confidence: 99%

Measurements of the actual evapotranspiration and crop coefficients of summer and winter seasons crops in Japan

Attarod¹,

Aoki²,

Bayramzadeh³

2009

PLANT SOIL ENVIRON

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The main goal was to understand the trends of actual evapotranspiration (AET) and crop coefficient (K c ) in summer and winter seasons crops in Japan, maize, soybean, wheat and Italian rye-grass. Bowen ratio energy balance technique (BREB) was applied to measure the AET and heat flux between ground surface and atmosphere. Measurements were carried out using an automatic weather station (AWS) installed seasonally in the experimental farm of Tokyo University of Agriculture and Technology (TUAT). Penman-Monteith equation recommended by FAO was used to calculate reference crop evapotranspiration (ET 0 ) and K c was obtained from the ratio of AET to ET 0 . The results indicated that the average amount of daytime AET in the winter and summer seasons crops were approximately 2.5 and 3.5 mm, respectively. Monthly daytime AET varied between 1.3 and 5.7 mm in winter season crops and between 1.4 and 6.5 mm in summer season crops. No significant differences between daily average values of AET for winter season as well as for summer season crops were found at 5% level of confidence (t = 0.9278, wheat and Italian rye-grass and t = 0.6781, soybean and maize). Average K c values of summer season crops were found to be slightly higher than those of winter seasons crops. For planning the irrigation scheduling, it is quite necessary to understand the behaviors of AET and K c during the growing season.

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Estimation of Crop Coefficients and Evapotranspiration by Meteorological Parameters in a Rain-fed Paddy Rice Field, Cassava and Teak Plantations in Thailand

Cited by 21 publications

References 6 publications

Impacts of Land Cover Changes on Hydrologic Responses: A Case Study of Chi River Basin, Thailand

Impacts of Land Cover Changes on Hydrologic Responses: A Case Study of Chi River Basin, Thailand

CO2 and H2O Fluxes Ratio in Paddy Fields of Thailand and Japan

Measurements of the actual evapotranspiration and crop coefficients of summer and winter seasons crops in Japan

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