scholarly journals Changes of Reference Evapotranspiration and Its Relationship to Dry/Wet Conditions Based on the Aridity Index in the Songnen Grassland, Northeast China

Water ◽  
2017 ◽  
Vol 9 (5) ◽  
pp. 316 ◽  
Author(s):  
Qiyun Ma ◽  
Jiquan Zhang ◽  
Caiyun Sun ◽  
Enliang Guo ◽  
Feng Zhang ◽  
...  
Keyword(s):  
Northeast China ◽  
Reference Evapotranspiration ◽  
Aridity Index

scholarly journals Variations of the Reference Evapotranspiration and Aridity Index Over Northeast China: Changing Properties and Possible Causes

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Liguo Cao ◽  
Zhengchao Zhou
Keyword(s):  
Northeast China ◽  
Reference Evapotranspiration ◽  
Correlation Coefficients ◽  
Aridity Index ◽  
Kendall Test ◽  
Study Region ◽  
Monsoon Index ◽  
Abrupt Changes ◽  
Temporal And Spatial ◽  
Wavelet Methods

Temporal and spatial variations in reference evapotranspiration (ET0) and aridity index (AI) can be used as important indexes for understanding climate change and its effects on ecosystem stability. Thus, in this work, we comprehensively investigated 71 meteorological stations in Northeast China from 1965 to 2017 to analyze the spatial-temporal variation and trend of ET0 and AI using the nonparametric Mann–Kendall test, the linear regression, and the Morlet wavelet methods. The results elucidated that ET0 for Northeast China as a whole exhibited a decrease at a rate of −1.97 mm/yr, AI declined at a rate of −0.01/yr during 1965–2017, and approximately 94% stations showed a decrease trend. Spatially, the high values of AI and ET0 were primarily at the western part of the study area except for the Heilongjiang province, and the stations showing low values were mainly distributed in the central and eastern part. The decreasing trends for AI were more obvious in the eastern part compared with the western part over the study region. The abrupt changes in AI occurred in 2005 and 2007, whereas only one abrupt change for ET0 occurred in 1995. For annual ET0, there were periods of 3, 7, 11, and 15 yr, and there existed periods of 1, 7, 11, and 13 yr for annual AI. The correlation coefficients implied wind speed and precipitation were the dominant meteorological factors resulting in the ET0 and AI decrease, respectively. Additionally, the change of the Indian summer monsoon index (ISMI) may also contribute to the weakened AI in the study area. Nevertheless, further investigation is still required to clarify the mechanisms for AI and ET0 variations in the future.

scholarly journals Changes of Reference Evapotranspiration and Its Relationships to Dry/Wet Conditions Based on Aridity Index in Songnen Grassland, Northeast China

2017 ◽  
Author(s):  
Qiyun Ma ◽  
Jiquan Zhang ◽  
Caiyun Sun ◽  
Enliang Guo ◽  
Feng Zhang ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Relative Humidity ◽  
Time Scales ◽  
Northeast China ◽  
Reference Evapotranspiration ◽  
Sunshine Duration ◽  
Aridity Index ◽  
Kendall Test ◽  
Positive Contribution ◽  
Different Time Scales

Reference evapotranspiration (ET0) plays an irreplaceable role in regional dry/wet conditions under the background of climate change. Based on the FAO Penman-Monteith method and daily climate variables, ET0 was calculated for 22 stations in and around Songnen Grassland, northeast China, during 1960-2014. The temporal and spatial variations of ET0 and precipitation (P) were comprehensively analyzed at different time scales by using the Mann-Kendall test, Sen’s slope estimator, and linear regression coupling with break trend analysis. Sensitivity analysis was used to detect the key climate parameter attributed to ET0 change. Then, the role of ET0 in regional dry/wet conditions was discussed by analyzing the relationship between ET0, P and aridity index (AI). Results shown a higher ET0 in the southwest and a lower in the northeast, but P was opposite to that of ET0. Evidently decreasing trend of ET0 at different time scales was detected in almost the entire region, and the significant trend mainly distributed in the eastern, northeastern and central. For the whole region, sensitivity analysis indicated decreasing trend of ET0 was primarily attributed to relative humidity and maximum air temperature. The positive contribution of increasing temperature rising to ET0 was offset by the effect of significantly decreasing relative humidity, wind speed and sunshine duration. In addition, the value of ET0 shown higher in drought years and lower in wet years.

Effect of climate change on reference evapotranspiration and aridity index in arid region of China

2013 ◽  
Vol 492 ◽  
pp. 24-34 ◽  
Author(s):  
Zailin Huo ◽  
Xiaoqin Dai ◽  
Shaoyuan Feng ◽  
Shaozhong Kang ◽  
Guanhua Huang
Keyword(s):  
Climate Change ◽  
Arid Region ◽  
Reference Evapotranspiration ◽  
Aridity Index

Changes in aridity index and reference evapotranspiration over the central and eastern Tibetan Plateau in China during 1960–2012

2014 ◽  
Vol 349 ◽  
pp. 280-286 ◽  
Author(s):  
Liuzhu Wang ◽  
Liguo Cao ◽  
Xiaojun Deng ◽  
Peihong Jia ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Reference Evapotranspiration ◽  
Aridity Index ◽  
Eastern Tibetan Plateau

scholarly journals Optimal Selection of Empirical Reference Evapotranspiration Method in 36 Different Agricultural Zones of China

Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 31
Author(s):  
Yong Yang ◽  
Rensheng Chen ◽  
Chuntan Han ◽  
Zhangwen Liu ◽  
Xiqiang Wang
Keyword(s):  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Aridity Index ◽  
Empirical Method ◽  
Climatic Conditions ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Temperature Method ◽  
The Relationship ◽  
Selection Of

The Food and Agriculture Organization has proposed the current version of the Penman–Monteith method (FAO56-PM) as the standard for calculating reference evapotranspiration (ET0); however, high meteorological data requirements limit its application in many areas. There is thus an urgent need to identify the best alternative empirical method to accurately calculate ET0 in regions that lack sufficient meteorological data. In this study, three temperature-based methods and five radiation-based methods were evaluated using ET0 values generated using the FAO56-PM method in 36 agricultural zones in China based on meteorological data from 823 stations, measured between 2011 and 2020. The results showed that the optimal temperature-based method and radiation-based method differed for different agricultural zones, and no one temperature method or radiation method could be suitable for all agricultural zones. The eight empirical methods were regionally calibrated to improve the ET0 calculation accuracy in the different zones. The relationship between the optimal methods and climatic conditions showed that the most reliable empirical method could be selected according to the local annual mean temperature and aridity index. The results provide useful guidance for the selection of reliable empirical ET0 methods in agricultural zones outside China.

Influence of the Sea-Land Interface Moisture Flux on Reference Evapotranspiration in Liaohe Delta, Northeast China

2013 ◽  
Vol 405-408 ◽  
pp. 2238-2244
Author(s):  
Bing Liang Wang ◽  
Guo Sheng Li
Keyword(s):  
Northeast China ◽  
Field Experiments ◽  
Reference Evapotranspiration ◽  
Moisture Flux ◽  
Ncep Reanalysis ◽  
Positive Correlation ◽  
The Past ◽  
Opposite Trend ◽  
Liaohe Delta ◽  
Monteith Equation

This study investigates the association between the sea-land interface moisture flux and reference evapotranspiration during 1971-2010 in Liaohe Delta, Northeast China, which moisture flux is derived from NCAR/NCEP reanalysis I data and reference evapotranspiration is calculated by Penman-Monteith equation. The result shows that the sea-land interface moisture flux presents a seasonal variation with the highest value in summer and the lowest value in winter. The sea-land interface moisture flux and reference evapotranspiration show significantly positive correlation in spring and autumn and significantly negative correlation in summer. Consistent with the past field experiments, the sea-land moisture flux suppresses reference evapotranspiration in summer. The positive correlation reveals that the sea-land moisture flux, especially in surface sublayer, facilitates reference evapotranspiration in spring and autumn. Regressions analysis demonstrate that reference evapotranspiration increases when moisture flux of surface-to-850-hPasublayer increases until reaches the threshold (67-75kg/ms), and the opposite trend appears when moisture flux exceeds the threshold.

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