Variation in actual evapotranspiration following changes in climate and vegetation cover during an ecological restoration period (2000–2015) in the Loess Plateau, China

• Published in: The Science of the total environment Vol. 689; pp. 534 - 545
• Main Authors: Ma, Zonghan, Yan, Nana, Wu, Bingfang, Stein, Alfred, Zhu, Weiwei, Zeng, Hongwei
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.11.2019
• Subjects: air; atmospheric pressure; China; Climate change; climatic factors; cropland; ecosystems; evapotranspiration; Evapotranspiration modelling; forest land; Grain for Green project; grasslands; humans; humidity; hydrologic cycle; land restoration; Loess Plateau; monitoring; Remote sensing; river flow; solar radiation; spatial variation; statistical analysis; sustainable development; temperature; temporal variation; vegetation cover; water conservation; water resources; Water sustainability; wind speed; China; Evapotranspiration modelling; Climate change; Water sustainability; Remote sensing; Grain for Green project; Loess Plateau
• DOI: 10.1016/j.scitotenv.2019.06.155
• ISSN: 0048-9697; 1879-1026

The spatial distribution of water resources largely influences Earth ecosystems and human civilization. Being a major component of the global water cycle, evapotranspiration (ET) serves as an indicator of the availability of water resources. Understanding the actual ET (ETa) variation mechanism at different spatial and temporal scales can improve management of water use within the sustainable development limits. In this study, remote sensing derived ETa data were used to study water resource fluctuations in the Loess Plateau, China. This region covers diverse climate types from humid to arid and experienced large changes in vegetation cover during a revegetation project between 2000 and 2015. The relations between spatiotemporal variation of ETa, climate factors and vegetation change were explored using statistical methods. The results show that cropland, forestland and grassland take the largest percentage of total ETa. Total ETa exhibited a marginally increasing trend (p < 0.1) during 2000–2010 and no trend during 2011–2015. Windspeed and vegetation cover index highly influenced ETa, followed by atmospheric pressure, air humidity, precipitation, bright sunshine duration and temperature. Temperature has little effect on ETa throughout the Loess Plateau. The monitoring of water resources based upon water balance between precipitation, ETa and river flow changes shows that water consumption deficit is consistent with vegetation changes: it was large during 2000–2010 when vegetation increased rapidly and decreased after 2010. These results could help to develop different water saving strategies across the Loess Plateau and build a better monitoring system of water resources. [Display omitted] •Actual evapotranspiration in the Loess Plateau is quantified and validated.•Windspeed is the dominant influential climate factor to actual evapotranspiration in research area.•Evapotranspiration variation is consistent with vegetation coverage change in the Loess Plateau.•Water deficit of the Loess Plateau fluctuated during revegetation period (2000–2015).