Isotope partitioning of evaporation and transpiration from the land surface: towards improved understanding of vapour-loss mechanisms

地表蒸发和蒸腾的同位素分配：提高对蒸气损失机制的理解

• 批准号: 228058-2010
• 负责人: Gibson, John
• 金额: $ 1.24万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=454733
• 关键词: Isotope; partitioning; evaporation; transpiration; land

This research centres on development, refinement and application of stable isotope techniques for tracing evaporation and transpiration in natural ecosystems. Isotopic tracing of vapour loss pathways is possible due to significant differences in behaviour of the naturally-occurring isotopic species of water during evaporation and transpiration, the former pathway being isotopically fractionating, and the latter being isotopically non-fractionating. As typically observed in natural systems, the isotopic composition of the transpiration flux will closely resemble that of soil water sources, whereas the evaporation flux will be distinctly labelled by a depleted heavy isotopic signature. Fingerprinting of vapour fluxes and residual waters using isotopes is explored to improve characterization of water and carbon budgets in complex wetland terrain, in regional surveys, large river basins and global scale modelling studies.

这项研究的中心是发展、改进和应用稳定同位素技术，追踪自然生态系统中的蒸发和蒸腾作用。蒸汽损失途径的同位素示踪是可能的，因为在蒸发和蒸腾过程中天然存在的水的同位素种类的行为的显着差异，前者的途径是同位素分馏，而后者是同位素非分馏。通常在自然系统中观察到的，蒸腾通量的同位素组成将非常类似于土壤水源，而蒸发通量将明显标记由耗尽的重同位素签名。探索使用同位素的蒸汽通量和残留沃茨的指纹，以改善复杂湿地地形，区域调查，大型河流流域和全球规模的建模研究中的水和碳收支的特性。