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Qinggai Wang - One of the best experts on this subject based on the ideXlab platform.
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Winter Wheat Canopy-Interception with Its Influence Factors under Sprinkler Irrigation
2004 Ottawa Canada August 1 - 4 2004, 2020Co-Authors: Yaohu Kang, Qinggai WangAbstract:Field studies on winter wheat Canopy-Interception with its relations to leaf area index, winter wheat height, drop size, wind speed and water application intensity were carried out. CanopyInterception was measured using the water wiping method. Results indicate that the maximum value of winter wheat Canopy-Interception was no more than 1.0 mm and quite smaller than that presented by previous investigators. The total Canopy-Interception was 2.4 mm, which occupied only 1.3% of the total irrigation amount (194.6 mm), for the four sprinkler irrigation events during whole period of winter wheat growth in 2003. Canopy-Interception increases as leaf area index and winter wheat height increases. A linear regression model is developed to express the relationship of CanopyInterception versus leaf area index and winter wheat height. Comparison indicates that there is good agreement between the values of Canopy-Interception measured using water wiping method and estimated using the linear regression model. Results also indicate that Canopy-Interception decreases as drop size and wind speed increases. An exponential relationship is found between Canopy-Interception and drop size, and a linear relationship is appeared between CanopyInterception and square wind speed. Water application intensity does not affect Canopy-Interception significantly.
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Method for Measurement of Canopy Interception under Sprinkler Irrigation
Journal of Irrigation and Drainage Engineering-asce, 2006Co-Authors: Qinggai Wang, Yaohu KangAbstract:A procedure called water wiping is developed to measure the amount of water intercepted by the Canopy of winter wheat under sprinkler irrigation. Macromolecule bibulous materials with high water absorption is used to collect sprinkler water intercepted by winter wheat Canopy by wiping water from leaves, sheathes, heads, and stems. A procedure is developed for application and verified using field experiments. The results show that this method is rational and applicable. This method could be used to measure Canopy Interception of other crops with small leaves and short heights.
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winter wheat Canopy Interception and its influence factors under sprinkler irrigation
Agricultural Water Management, 2005Co-Authors: Yaohu Kang, Qinggai WangAbstract:Field studies on winter wheat Canopy Interception with its relations to leaf area index (LAI), plant height, drop diameter, wind speed, and water application intensity were carried out. Canopy Interception was measured using the water wiping method. Results indicate that the maximum value of winter wheat Canopy Interception was not more than 1.0 mm, much smaller than presented by previous investigators. The total Canopy Interception for the growing season was 2.4 mm, only 1.3% of the total irrigation amount (194.6 mm), for four sprinkler irrigation events during 2003. Canopy Interception increased as leaf area index and plant height increased. A linear regression model was developed to express the relationship of Canopy Interception with leaf area index and plant height. There was good agreement between the values of Canopy Interception measured using the water wiping method and estimated using the linear regression model. Results also indicate that Canopy Interception decreased as drop diameter and wind speed increased. An exponential relationship was found between Canopy Interception and drop size, and a linear relationship between Canopy Interception and the square of the wind speed. Water application intensity does not affect Canopy Interception significantly.
Kyoichi Otsuki - One of the best experts on this subject based on the ideXlab platform.
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comparative modeling of the effects of intensive thinning on Canopy Interception loss in a japanese cedar cryptomeria japonica d don forest of western japan
Agricultural and Forest Meteorology, 2015Co-Authors: Yoshinori Shinohara, Delphis F Levia, Hikaru Komatsu, Mari Nogata, Kyoichi OtsukiAbstract:Abstract In the last several years, thinning has been conducted in coniferous plantations throughout Japan, mainly to secure water resources. Although Canopy Interception loss ( I c ) is a major component of evapotranspiration, this is among the first studies that have examined changes in I c while considering the effects of thinning in Japanese cedar ( Cryptomeria japonica ) forests, the most common type of plantation in Japan. We compared and contrasted three Canopy Interception models (Mulder, revised Gash, WiMo) before and after intensive thinning operations. The experimental Japanese cedar forest was intensively thinned with removal of 54% of all stems, reducing the basal area by 50% from 99.7 to 49.6 m 2 ha −1 . Prior to thinning, all three Canopy Interception models performed well with root mean square errors for the Mulder, revised Gash, and WiMo models of 2.96, 3.59, and 3.81 mm, respectively; while those after thinning were 1.32, 2.37, 2.38 mm, respectively. In addition, all three Canopy Interception models performed better than the mean before thinning as evaluated by the Nash–Sutcliffe model efficiency with values 0.51 (Mulder), 0.28 (revised Gash), and 0.19 (WiMo) but did not perform as well after heavy thinning. These results suggest that Canopy Interception models might not be applicable after intensive thinning of Japanese cedar forests.
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comparisons of soil water content between a moso bamboo phyllostachys pubescens forest and an evergreen broadleaved forest in western japan
Plant Species Biology, 2015Co-Authors: Yoshinori Shinohara, Kyoichi OtsukiAbstract:In Japan, forests of Moso bamboo (Phyllostachys pubescens, an exotic invasive giant bamboo) have naturalized and expanded rapidly, replacing surrounding broadleaved and coniferous forests. To evaluate impacts caused by these forest-type replacements on the hydrological cycle, soil-water content and its spatial variability in a Moso bamboo forest were compared with those in an adjacent evergreen broadleaved forest, in a case study of a stand in western Japan (northern Kyushu). The volumetric soil-water content averaged over depths between 0 and 60 cm was consistently higher in the bamboo stand than that in the broadleaved stand. These results contrast with previous studies comparing the soil-water content in Moso bamboo forests with that in other forest types. The sum of Canopy transpiration and soil evaporation (E) in the bamboo stand tended to be larger than that in the broadleaved stand. Small Canopy Interception loss was reported in the bamboo forest. Therefore, the large amount of E would counterbalance the small Canopy Interception loss in the bamboo forest. Differences in soil characteristics between the two stands may be the main factor causing differences in soil-water content. Spatial variation in soil-water content in the bamboo stand was larger than that in the broadleaved stand, confirming findings in a previous series of our study. This could happen because the well-developed root-system in the bamboo forest enhances preferential flow in the soil. To evaluate the effects of aggressive invasion of alien giant bamboo on the ecosystem functions, we recommend further studies measuring various hydrological components in various Moso bamboo forests.
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forest Canopy Interception loss exceeds wet Canopy evaporation in japanese cypress hinoki and japanese cedar sugi plantations
Journal of Hydrology, 2013Co-Authors: Yoshinori Shinohara, Takami Saito, Hiroki Matsuda, Misako Komatsu, Yang Xiang, Atsuhiro Takahashi, Kyoichi OtsukiAbstract:Summary The aim of this study is to evaluate rainfall partitioning at the forest Canopy and reveal the physical process of Canopy Interception loss. Observations were conducted for 19 months in neighboring stands of Chamaecyparis obtusa Sieb. et Zucc. (Hinoki) and Cryptomeria japonica D. Don (Sugi). Cumulative amounts for the period showed that portions of throughfall ( TF ), stemflow ( SF ) and Interception ( IC ) to rainfall ( RF ) for Hinoki were 65.3%, 9.1%, and 25.5%, respectively. Corresponding values for Sugi were 67.9%, 6.6%, and 25.5%. The smaller TF and larger SF in Hinoki than those in Sugi were induced by greater mean funneling ratio of a tree and greater tree density in Hinoki. Similar IC / RF would result from similar leaf area index. In analyses for rainfall events, rainfall period ( RP ) was defined as the period excluding short no-rainfall periods within an event, and rainfall intensity ( RFI ) was as RF / RP . In events with Canopy saturation ( RF ⩾ 10 mm), IC / RF was insensitive to RP and RFI . This was related to an increasing rate of IC with RFI . Evaporation for IC estimated by the model, based on the Penman–Monteith equation, was approximately 40% of cumulative IC observed. Underestimation was great in events with long RP , but not with large RFI . We suggest that large amount of IC occurred during rainfall, which is induced by splash droplets transport (SDT) by Canopy ventilation.
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characteristics of Canopy Interception loss in moso bamboo forests of japan
Hydrological Processes, 2013Co-Authors: Yoshinori Shinohara, Hikaru Komatsu, Kohei Kuramoto, Kyoichi OtsukiAbstract:In recent years, Moso bamboo (Phyllostachys pubescens) forests have rapidly expanded in Japan by replacing surrounding coniferous and/or broadleaved forests. To evaluate the change in water yield from forested areas because of this replacement, it is necessary to examine evapotranspiration for Moso bamboo forests. However, Canopy Interception loss, one of the major components of evapotranspiration in forested areas, has been observed in only two Moso bamboo forests in Japan with relatively high stem density (~7000 stems/ha). There are, in fact, many Moso bamboo forests with much lower stem density. Thus, we made precipitation (Pr), throughfall (Tf) and stemflow (Sf) observations for 1 year in a Moso bamboo forest with stem density of 3611 stems/ha and quantified Canopy Interception loss (Ic). Pr and Ic for the experimental period were 1636 and 166 mm, respectively, and Ic/Pr was 10%. The value was approximately the same as values for the other two Moso bamboo forests and lower than values for coniferous and broadleaved forests. On the other hand, Tf/Pr and Sf/Pr for our forest (86% and 4%, respectively) were approximately 10% of Pr larger and smaller than values for the other two Moso bamboo forests. These results suggest that the difference in stem density greatly affects precipitation partitioning (i.e. Tf/Pr and Sf/Pr) but does not greatly change Ic/Pr. Copyright © 2012 John Wiley & Sons, Ltd.
Yoshinori Shinohara - One of the best experts on this subject based on the ideXlab platform.
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correction of Canopy Interception loss measurements in temperate forests a comparison of necessary adjustments among three different rain gauges based on a dynamic calibration procedure
Journal of Hydrometeorology, 2018Co-Authors: Shinichi Iida, Delphis F Levia, Kazuki Nanko, Takanori Shimizu, Koji Tamai, Yoshinori ShinoharaAbstract:ABSTRACTTipping-bucket rain gauges are used widely to measure the amount and intensity of gross rainfall and throughfall in forests, despite the fact that their systematic underestimations are well known. To the knowledge of the authors, no dynamic calibrations for the budget-conscious Davis gauge (Rain Collector II, Davis Instruments, California) have been published. Thus, five Davis gauges were dynamically calibrated under different constant intensities of inflow and a correction equation was derived. The derived correction equation for the Davis rain gauge is V = −0.2005Q2 + 0.702Q + 1 (R2 = 0.95, p < 0.001), where V is the actual volume of a single tip scaled by the static volume of single tip c (cm3 cm−3), and Q is actual inflow scaled by c (s−1). The Davis rain gauge was then compared to the Onset rain gauge and the Ota rain gauge, and the corrections were applied to field observation data of Canopy Interception loss from a temperate forest in Japan. It is necessary to apply corrections to gross rai...
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comparative modeling of the effects of intensive thinning on Canopy Interception loss in a japanese cedar cryptomeria japonica d don forest of western japan
Agricultural and Forest Meteorology, 2015Co-Authors: Yoshinori Shinohara, Delphis F Levia, Hikaru Komatsu, Mari Nogata, Kyoichi OtsukiAbstract:Abstract In the last several years, thinning has been conducted in coniferous plantations throughout Japan, mainly to secure water resources. Although Canopy Interception loss ( I c ) is a major component of evapotranspiration, this is among the first studies that have examined changes in I c while considering the effects of thinning in Japanese cedar ( Cryptomeria japonica ) forests, the most common type of plantation in Japan. We compared and contrasted three Canopy Interception models (Mulder, revised Gash, WiMo) before and after intensive thinning operations. The experimental Japanese cedar forest was intensively thinned with removal of 54% of all stems, reducing the basal area by 50% from 99.7 to 49.6 m 2 ha −1 . Prior to thinning, all three Canopy Interception models performed well with root mean square errors for the Mulder, revised Gash, and WiMo models of 2.96, 3.59, and 3.81 mm, respectively; while those after thinning were 1.32, 2.37, 2.38 mm, respectively. In addition, all three Canopy Interception models performed better than the mean before thinning as evaluated by the Nash–Sutcliffe model efficiency with values 0.51 (Mulder), 0.28 (revised Gash), and 0.19 (WiMo) but did not perform as well after heavy thinning. These results suggest that Canopy Interception models might not be applicable after intensive thinning of Japanese cedar forests.
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comparisons of soil water content between a moso bamboo phyllostachys pubescens forest and an evergreen broadleaved forest in western japan
Plant Species Biology, 2015Co-Authors: Yoshinori Shinohara, Kyoichi OtsukiAbstract:In Japan, forests of Moso bamboo (Phyllostachys pubescens, an exotic invasive giant bamboo) have naturalized and expanded rapidly, replacing surrounding broadleaved and coniferous forests. To evaluate impacts caused by these forest-type replacements on the hydrological cycle, soil-water content and its spatial variability in a Moso bamboo forest were compared with those in an adjacent evergreen broadleaved forest, in a case study of a stand in western Japan (northern Kyushu). The volumetric soil-water content averaged over depths between 0 and 60 cm was consistently higher in the bamboo stand than that in the broadleaved stand. These results contrast with previous studies comparing the soil-water content in Moso bamboo forests with that in other forest types. The sum of Canopy transpiration and soil evaporation (E) in the bamboo stand tended to be larger than that in the broadleaved stand. Small Canopy Interception loss was reported in the bamboo forest. Therefore, the large amount of E would counterbalance the small Canopy Interception loss in the bamboo forest. Differences in soil characteristics between the two stands may be the main factor causing differences in soil-water content. Spatial variation in soil-water content in the bamboo stand was larger than that in the broadleaved stand, confirming findings in a previous series of our study. This could happen because the well-developed root-system in the bamboo forest enhances preferential flow in the soil. To evaluate the effects of aggressive invasion of alien giant bamboo on the ecosystem functions, we recommend further studies measuring various hydrological components in various Moso bamboo forests.
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forest Canopy Interception loss exceeds wet Canopy evaporation in japanese cypress hinoki and japanese cedar sugi plantations
Journal of Hydrology, 2013Co-Authors: Yoshinori Shinohara, Takami Saito, Hiroki Matsuda, Misako Komatsu, Yang Xiang, Atsuhiro Takahashi, Kyoichi OtsukiAbstract:Summary The aim of this study is to evaluate rainfall partitioning at the forest Canopy and reveal the physical process of Canopy Interception loss. Observations were conducted for 19 months in neighboring stands of Chamaecyparis obtusa Sieb. et Zucc. (Hinoki) and Cryptomeria japonica D. Don (Sugi). Cumulative amounts for the period showed that portions of throughfall ( TF ), stemflow ( SF ) and Interception ( IC ) to rainfall ( RF ) for Hinoki were 65.3%, 9.1%, and 25.5%, respectively. Corresponding values for Sugi were 67.9%, 6.6%, and 25.5%. The smaller TF and larger SF in Hinoki than those in Sugi were induced by greater mean funneling ratio of a tree and greater tree density in Hinoki. Similar IC / RF would result from similar leaf area index. In analyses for rainfall events, rainfall period ( RP ) was defined as the period excluding short no-rainfall periods within an event, and rainfall intensity ( RFI ) was as RF / RP . In events with Canopy saturation ( RF ⩾ 10 mm), IC / RF was insensitive to RP and RFI . This was related to an increasing rate of IC with RFI . Evaporation for IC estimated by the model, based on the Penman–Monteith equation, was approximately 40% of cumulative IC observed. Underestimation was great in events with long RP , but not with large RFI . We suggest that large amount of IC occurred during rainfall, which is induced by splash droplets transport (SDT) by Canopy ventilation.
-
characteristics of Canopy Interception loss in moso bamboo forests of japan
Hydrological Processes, 2013Co-Authors: Yoshinori Shinohara, Hikaru Komatsu, Kohei Kuramoto, Kyoichi OtsukiAbstract:In recent years, Moso bamboo (Phyllostachys pubescens) forests have rapidly expanded in Japan by replacing surrounding coniferous and/or broadleaved forests. To evaluate the change in water yield from forested areas because of this replacement, it is necessary to examine evapotranspiration for Moso bamboo forests. However, Canopy Interception loss, one of the major components of evapotranspiration in forested areas, has been observed in only two Moso bamboo forests in Japan with relatively high stem density (~7000 stems/ha). There are, in fact, many Moso bamboo forests with much lower stem density. Thus, we made precipitation (Pr), throughfall (Tf) and stemflow (Sf) observations for 1 year in a Moso bamboo forest with stem density of 3611 stems/ha and quantified Canopy Interception loss (Ic). Pr and Ic for the experimental period were 1636 and 166 mm, respectively, and Ic/Pr was 10%. The value was approximately the same as values for the other two Moso bamboo forests and lower than values for coniferous and broadleaved forests. On the other hand, Tf/Pr and Sf/Pr for our forest (86% and 4%, respectively) were approximately 10% of Pr larger and smaller than values for the other two Moso bamboo forests. These results suggest that the difference in stem density greatly affects precipitation partitioning (i.e. Tf/Pr and Sf/Pr) but does not greatly change Ic/Pr. Copyright © 2012 John Wiley & Sons, Ltd.
Yaohu Kang - One of the best experts on this subject based on the ideXlab platform.
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Winter Wheat Canopy-Interception with Its Influence Factors under Sprinkler Irrigation
2004 Ottawa Canada August 1 - 4 2004, 2020Co-Authors: Yaohu Kang, Qinggai WangAbstract:Field studies on winter wheat Canopy-Interception with its relations to leaf area index, winter wheat height, drop size, wind speed and water application intensity were carried out. CanopyInterception was measured using the water wiping method. Results indicate that the maximum value of winter wheat Canopy-Interception was no more than 1.0 mm and quite smaller than that presented by previous investigators. The total Canopy-Interception was 2.4 mm, which occupied only 1.3% of the total irrigation amount (194.6 mm), for the four sprinkler irrigation events during whole period of winter wheat growth in 2003. Canopy-Interception increases as leaf area index and winter wheat height increases. A linear regression model is developed to express the relationship of CanopyInterception versus leaf area index and winter wheat height. Comparison indicates that there is good agreement between the values of Canopy-Interception measured using water wiping method and estimated using the linear regression model. Results also indicate that Canopy-Interception decreases as drop size and wind speed increases. An exponential relationship is found between Canopy-Interception and drop size, and a linear relationship is appeared between CanopyInterception and square wind speed. Water application intensity does not affect Canopy-Interception significantly.
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Method for Measurement of Canopy Interception under Sprinkler Irrigation
Journal of Irrigation and Drainage Engineering-asce, 2006Co-Authors: Qinggai Wang, Yaohu KangAbstract:A procedure called water wiping is developed to measure the amount of water intercepted by the Canopy of winter wheat under sprinkler irrigation. Macromolecule bibulous materials with high water absorption is used to collect sprinkler water intercepted by winter wheat Canopy by wiping water from leaves, sheathes, heads, and stems. A procedure is developed for application and verified using field experiments. The results show that this method is rational and applicable. This method could be used to measure Canopy Interception of other crops with small leaves and short heights.
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winter wheat Canopy Interception and its influence factors under sprinkler irrigation
Agricultural Water Management, 2005Co-Authors: Yaohu Kang, Qinggai WangAbstract:Field studies on winter wheat Canopy Interception with its relations to leaf area index (LAI), plant height, drop diameter, wind speed, and water application intensity were carried out. Canopy Interception was measured using the water wiping method. Results indicate that the maximum value of winter wheat Canopy Interception was not more than 1.0 mm, much smaller than presented by previous investigators. The total Canopy Interception for the growing season was 2.4 mm, only 1.3% of the total irrigation amount (194.6 mm), for four sprinkler irrigation events during 2003. Canopy Interception increased as leaf area index and plant height increased. A linear regression model was developed to express the relationship of Canopy Interception with leaf area index and plant height. There was good agreement between the values of Canopy Interception measured using the water wiping method and estimated using the linear regression model. Results also indicate that Canopy Interception decreased as drop diameter and wind speed increased. An exponential relationship was found between Canopy Interception and drop size, and a linear relationship between Canopy Interception and the square of the wind speed. Water application intensity does not affect Canopy Interception significantly.
Xuexiang Chang - One of the best experts on this subject based on the ideXlab platform.
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spatial variability of Canopy Interception in a spruce forest of the semiarid mountain regions of china
Agricultural and Forest Meteorology, 2014Co-Authors: Zhibin He, Junjun Yang, Jun Du, Wenzhi Zhao, Xuexiang ChangAbstract:Canopy Interception has large spatial variability which complicates measurements and achievement of spatial representation. In the present study, we measured gross rainfall and throughfall from June 2011 to October 2012, and leaf area index (LAI), plant area index (PAI), and spatial locations of trees within Picea crassifolia forest in Qilian mountains of northwestern China. Spatial variability of Canopy Interception and related factors, and the minimum number and locations of collectors were analyzed by statistical techniques. The results show that spatial variation of Canopy Interception has a significant relationship with PAI, but not with LAI. This indicates that PAI is more appropriate parameters for a Canopy Interception model than LAI. Based on the relationship between Canopy Interception loss and PAI, the minimum number and locations of collectors were estimated. In this study, 10–12 collectors yielded representative throughfall in the forest, but these collectors required to be placed at the sites of mean values of PAI.