A Stable Isotope Approach for Estimating the Contribution of Recycled Moisture to Precipitation in Lanzhou City, China

Abstract

The proportional contribution of recycled moisture to local precipitation is a geographically dependent parameter that cannot be ignored in water budgets. Stable hydrogen and oxygen isotopes are sensitive to environmental changes and can be applied to investigate the modern water cycle. In this study, a three-component mixing model is used to calculate the contribution of different water vapors (advection, evaporation and transpiration) to summer precipitation in Lanzhou city, Northwest China. The results show that for all sampling sites in Lanzhou, the contribution of advection vapor to precipitation is the largest, followed by the plant transpiration vapor, and the contribution of surface evaporation water vapor is usually the least, with the average values of 87.96%, 9.1% and 2.9%, respectively. The spatial differences of plant transpiration vapor are generally larger than those of advection vapor and surface evaporation vapor, and the high values appear in Yongdeng, Daheng and Gaolan.

Response of Meiyu process considering the temporal and spatial characteristics of GNSS PWV

“…In 2008, Jin SG et al [5] conducted the first regional GPS study on the spatiotemporal distribution and evolution of atmospheric precipitable water vapor in China from 2004 to 2007, discovering the pronounced seasonal characteristics of GPS PWV. Subsequently, many scholars have conducted research on the spatial distribution and spatiotemporal evolution of water vapor in areas such as the Qinling Mountains [6], coastal areas [7], and Lanzhou City [8] based on GNSS PWV and multiple meteorological data, contributing to a deeper understanding of regional precipitation, evaporation, and other weather processes. Zhu M et al [9] monitored the spatiotemporal variation of PWV during the life cycle of a super typhoon and found a close correlation between the spatiotemporal variability of PWV and the typhoon's movement, as well as a coincidence with the maximum rainfall during the typhoon.…”