Environmental and biophysical effects of evapotranspiration in semiarid grassland and maize cropland ecosystems over the summer monsoon transition zone of China

Ping Yue, Qiang Zhang, Xueyuan Ren, Zesu Yang, Hongyu Li and Yang Yang

Agricultural Water Management, 2022, vol. 264, issue C

Abstract: Accurate quantification of semiarid energy partitioning and actual evapotranspiration (ETc) is necessary to understand the variability in regional energy and the water cycle, which is expected to intensify under climate change. The seasonal and interannual variability in surface energy and ET and its responses to environmental and biophysical factors of grassland and cropland with maize (Zea mays), and ecosystems over the East Asian summer monsoon transition zone of China, were investigated using multiyear (2003–2008) eddy covariance measurements. The study sites received 65–84% of the annual precipitation (Pr) during the East Asian summer monsoon (EASM; June–August), with the lowest values in the weak EASM years of 2004 and 2007. Seasonal and interannual variations in the portioning of net radiation to turbulent fluxes were mainly controlled by Pr via changes in soil water content (SWC) and vegetation growth. Drastic changes in the Bowen ratio, vegetation growth, and energy fluxes occurred after the onset of EASM. During the cool winter and dry spring and autumn, the sensible heat flux was the largest component of the energy balance, and the latent heat flux dominated during warm and wet periods of summer. Monthly ET was 24.8 and 25.6 mm for the grassland and cropland, respectively, and they peaked at 89.0 mm and 113.9 mm, respectively, in July. Monthly ET was positively correlated with monthly Pr, Ta, the soil water drought stress index, normalized difference vegetation index (NDVI), the surface conductance (Gs), and the Priestley–Taylor coefficient (ET/ETeq) during the growing seasons (April–September). Annual ET varied from 215 to 373 mm in grassland and from 227 to 390 mm in cropland, with the lowest value during the severe drought year of 2007. Interannual variations in ET were primarily controlled by annual effective precipitation frequency, and interannual variations in summer ET were modulated by the summer monsoon duration period through changes in summer Pr, SWC, and vegetation growth.

Keywords: Semiarid region; Effective precipitation frequency; Drought stress index; Bulk parameters; Summer monsoon period (search for similar items in EconPapers)
Date: 2022
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0378377422000099
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:agiwat:v:264:y:2022:i:c:s0378377422000099

DOI: 10.1016/j.agwat.2022.107462

Access Statistics for this article

Agricultural Water Management is currently edited by B.E. Clothier, W. Dierickx, J. Oster and D. Wichelns

More articles in Agricultural Water Management from Elsevier
Bibliographic data for series maintained by Catherine Liu ().