Impacts of climate change and land-use change on summer water vapor contribution in Eastern China based on a Bayesian isotopic mixing model

Authors: CHEN, JLACHENG - Wuhan University; CHEN, JLE - Wuhan University; Zhang, Xunchang

Submitted to: Journal of Climate
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2024
Publication Date: 2/1/2025
Citation: Chen, J., Chen, J., Zhang, X.J. 2025. Impacts of climate change and land-use change on summer water vapor contribution in Eastern China based on a Bayesian isotopic mixing model. Journal of Climate. 38(3):761-780. https://doi.org/10.1175/JCLI-D-23-0566.1.
DOI: https://doi.org/10.1175/JCLI-D-23-0566.1

Interpretive Summary: Atmospheric moisture transport plays an important role in hydrological processes, influencing water cycles at global and regional scales. Investigating the change in moisture sources of precipitation is helpful to understand the precipitation change and its cause. Using computer models, this study determines the contribution change of moisture sources for precipitation and the difference of moisture sources under different land use and cover in East China. The study estimated that the mean contributions of atmospheric advection (horizontal air flow), evaporation and transpiration moisture to summer precipitation during 1969-2017 are 80.3%, 5.1%, and 14.5%, respectively. Among the advection moisture, moisture from Eurasia and the Western Pacific Ocean contributes most to the precipitation in North China; and moisture from the Indian Ocean, the South China Sea and the Western Pacific Ocean contributes most in South China. The contribution of advection moisture to precipitation decreases at the rate of 0.7 %/decade, while the contributions of evaporation and transpiration moisture increase at the rate of 0.2 %/decade and 0.5 %/decade, respectively. Advection moisture contribution is the controlling factor of summer precipitation change. In addition, the contributions of evaporation and transpiration moisture to precipitation are influenced by land use and cover type. The contributions of evaporation and transpiration moisture to precipitation in regions with large-proportion forests are higher than those with cultivated lands, while the contributions with small-proportion forests are lower than those with cultivated lands. This work is useful to climatologists and hydrologists to understand how moisture sources changes affect water cycles in the study regions. USDA is an equal opportunity provider and employer.

Technical Abstract: Moisture transport plays an important role in hydrological processes, influencing water cycles at global and regional scales. Investigating the change in moisture sources of precipitation is helpful to understand the precipitation change and its cause. Combining the Bayesian isotopic mixing model and the Hybrid Single-Particle Lagrangian Integrated Trajectory model, this study determines the contribution change of moisture sources for precipitation and the difference of moisture sources under different land use and cover in East China. The study estimated that the mean contributions of advection, evaporation and transpiration moisture to summer precipitation during 1969-2017 are 80.3%, 5.1%, and 14.5%, respectively. Among the advection moisture, moisture from Eurasia and the Western Pacific Ocean contributes most to the precipitation in North China, and moisture from the Indian Ocean, the South China Sea and the Western Pacific Ocean contributes most in South China. The contribution of advection moisture to precipitation decreases at the rate of 0.7 %/decade, while the contributions of evaporation and transpiration moisture increase at the rate of 0.2 %/decade and 0.5 %/decade, respectively. Advection moisture contribution is the controlling factor of summer precipitation change, while local evaporation and transpiration moisture are also contributors. In addition, the contributions of evaporation and transpiration moisture to precipitation are influenced by land use and cover type. The contributions of evaporation and transpiration moisture to precipitation for large-proportion forests are higher than those for cultivated lands, while the contributions for small-proportion forests are lower than those for cultivated lands. USDA is an equal opportunity provider and employer.