Characteristics of Evapotranspiration and Crop Coefficient Correction at a Permafrost Swamp Meadow in Dongkemadi Watershed, the Source of Yangtze River in Interior Qinghai–Tibet Plateau
The Qinghai–Tibet Plateau (QTP), known as the Earth’s third pole, is highly sensitive to climate change. Various environmental degradation has occurred due to the effects of climate warming such as the degradation of permafrost and the thickening of active layers. Evapotranspiration, as a key elemen...
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ftmdpi:oai:mdpi.com:/2073-4441/14/21/3578/ 2023-08-20T04:09:13+02:00 Characteristics of Evapotranspiration and Crop Coefficient Correction at a Permafrost Swamp Meadow in Dongkemadi Watershed, the Source of Yangtze River in Interior Qinghai–Tibet Plateau Haonan Guo Shaoyong Wang Xiaobo He Yongjian Ding Yawei Fan Hui Fu Xiaofeng Hong agris 2022-11-07 application/pdf https://doi.org/10.3390/w14213578 EN eng Multidisciplinary Digital Publishing Institute Hydrology https://dx.doi.org/10.3390/w14213578 https://creativecommons.org/licenses/by/4.0/ Water; Volume 14; Issue 21; Pages: 3578 evapotranspiration alpine swamp meadow Eddy covariance system crop coefficient Text 2022 ftmdpi https://doi.org/10.3390/w14213578 2023-08-01T07:13:50Z The Qinghai–Tibet Plateau (QTP), known as the Earth’s third pole, is highly sensitive to climate change. Various environmental degradation has occurred due to the effects of climate warming such as the degradation of permafrost and the thickening of active layers. Evapotranspiration, as a key element of hydrothermal coupling, has become a key factor of the plateau environment for deciphering deterioration, and the FAO P-M model has a good physical foundation and simple model data requirements as a primary tool to study the plateau evapotranspiration. There has been a large research base, but the estimation of evapotranspiration in alpine regions is still subject to many uncertainties. This is reflected in the fact that the classification of underlying surface types has not been sufficiently detailed and the evapotranspiration characteristics of some special underlying surface types are still unclear. Therefore, in this work, we modified the FAO P-M coefficients based on the characteristics of actual evapotranspiration measured by the Eddy covariance system and the key influencing factors to better simulate the actual evapotranspiration in alpine swamp meadow. The results were as follows: (1) Both ETa measured by the Eddy covariance system and ET0 calculated by FAO P-M showed the same trend at the daily and annual scales and hysteresis was confirmed to exist, so the error caused by hysteresis should be considered in further research. (2) The annual ETa was 566.97 mm and annual ETa/P was 0.76, and about 11.19% of ETa occurred during the night. The ETa was 2.15 during the non-growing seasons, implying that a large amount of soil water was released into the air by evapotranspiration. (3) The evapotranspiration characteristics of alpine swamp meadow are formed under the following conditions: control of net radiation (Rn) affected by VPD during the growing season and affected by soil temperature and humidity during the non-growing season. Precipitation and soil water content are no longer the main controlling factors ... Text permafrost MDPI Open Access Publishing Eta ENVELOPE(-62.917,-62.917,-64.300,-64.300) Water 14 21 3578 |
institution |
Open Polar |
collection |
MDPI Open Access Publishing |
op_collection_id |
ftmdpi |
language |
English |
topic |
evapotranspiration alpine swamp meadow Eddy covariance system crop coefficient |
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evapotranspiration alpine swamp meadow Eddy covariance system crop coefficient Haonan Guo Shaoyong Wang Xiaobo He Yongjian Ding Yawei Fan Hui Fu Xiaofeng Hong Characteristics of Evapotranspiration and Crop Coefficient Correction at a Permafrost Swamp Meadow in Dongkemadi Watershed, the Source of Yangtze River in Interior Qinghai–Tibet Plateau |
topic_facet |
evapotranspiration alpine swamp meadow Eddy covariance system crop coefficient |
description |
The Qinghai–Tibet Plateau (QTP), known as the Earth’s third pole, is highly sensitive to climate change. Various environmental degradation has occurred due to the effects of climate warming such as the degradation of permafrost and the thickening of active layers. Evapotranspiration, as a key element of hydrothermal coupling, has become a key factor of the plateau environment for deciphering deterioration, and the FAO P-M model has a good physical foundation and simple model data requirements as a primary tool to study the plateau evapotranspiration. There has been a large research base, but the estimation of evapotranspiration in alpine regions is still subject to many uncertainties. This is reflected in the fact that the classification of underlying surface types has not been sufficiently detailed and the evapotranspiration characteristics of some special underlying surface types are still unclear. Therefore, in this work, we modified the FAO P-M coefficients based on the characteristics of actual evapotranspiration measured by the Eddy covariance system and the key influencing factors to better simulate the actual evapotranspiration in alpine swamp meadow. The results were as follows: (1) Both ETa measured by the Eddy covariance system and ET0 calculated by FAO P-M showed the same trend at the daily and annual scales and hysteresis was confirmed to exist, so the error caused by hysteresis should be considered in further research. (2) The annual ETa was 566.97 mm and annual ETa/P was 0.76, and about 11.19% of ETa occurred during the night. The ETa was 2.15 during the non-growing seasons, implying that a large amount of soil water was released into the air by evapotranspiration. (3) The evapotranspiration characteristics of alpine swamp meadow are formed under the following conditions: control of net radiation (Rn) affected by VPD during the growing season and affected by soil temperature and humidity during the non-growing season. Precipitation and soil water content are no longer the main controlling factors ... |
format |
Text |
author |
Haonan Guo Shaoyong Wang Xiaobo He Yongjian Ding Yawei Fan Hui Fu Xiaofeng Hong |
author_facet |
Haonan Guo Shaoyong Wang Xiaobo He Yongjian Ding Yawei Fan Hui Fu Xiaofeng Hong |
author_sort |
Haonan Guo |
title |
Characteristics of Evapotranspiration and Crop Coefficient Correction at a Permafrost Swamp Meadow in Dongkemadi Watershed, the Source of Yangtze River in Interior Qinghai–Tibet Plateau |
title_short |
Characteristics of Evapotranspiration and Crop Coefficient Correction at a Permafrost Swamp Meadow in Dongkemadi Watershed, the Source of Yangtze River in Interior Qinghai–Tibet Plateau |
title_full |
Characteristics of Evapotranspiration and Crop Coefficient Correction at a Permafrost Swamp Meadow in Dongkemadi Watershed, the Source of Yangtze River in Interior Qinghai–Tibet Plateau |
title_fullStr |
Characteristics of Evapotranspiration and Crop Coefficient Correction at a Permafrost Swamp Meadow in Dongkemadi Watershed, the Source of Yangtze River in Interior Qinghai–Tibet Plateau |
title_full_unstemmed |
Characteristics of Evapotranspiration and Crop Coefficient Correction at a Permafrost Swamp Meadow in Dongkemadi Watershed, the Source of Yangtze River in Interior Qinghai–Tibet Plateau |
title_sort |
characteristics of evapotranspiration and crop coefficient correction at a permafrost swamp meadow in dongkemadi watershed, the source of yangtze river in interior qinghai–tibet plateau |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2022 |
url |
https://doi.org/10.3390/w14213578 |
op_coverage |
agris |
long_lat |
ENVELOPE(-62.917,-62.917,-64.300,-64.300) |
geographic |
Eta |
geographic_facet |
Eta |
genre |
permafrost |
genre_facet |
permafrost |
op_source |
Water; Volume 14; Issue 21; Pages: 3578 |
op_relation |
Hydrology https://dx.doi.org/10.3390/w14213578 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/w14213578 |
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Water |
container_volume |
14 |
container_issue |
21 |
container_start_page |
3578 |
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1774722023721795584 |