ZHANG Haifa1, ZHENG Fangwen2, YANG Haiquan3
（1.Technology Advisory of Pearl water Resources Commission (Guangzhou) Co., Ltd., Guangzhou 510610;
2.College of Hydraulic and Ecological Engineering, Nanchang Institute of Technology College, Nanchang 330099;
3.State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081）
Abstract：Nanchang city is located in the middle and lower reaches of the Yangtze River Basin, it is close to Poyang Lake, the largest freshwater lake in China, with hydrological network well-developed. In order to deeply understand the moisture source and transport of atmospheric precipitation in Nanchang and provide basic data for regional water cycle research, this study collected 93 daily precipitation event samples in Nanchang from 2015 to 2016 to investigate the stable H-O isotope characteristics and influencing factors of precipitation and attempted to clarify the water vapor source of precipitation. The results showed that: (1) the ranges of precipitation 18O and 2H were large, which was more positive in spring than in other seasons, and were not restricted by a single meteorological factor, but resulted from the mutual influences of multiple factors; (2) the local meteoric water line equation was 2H=8.0318O+12.1, and the stable H-O isotope fractionations were in relatively balance states, which can provide a reliable reference for the study of regional water cycle. The comprehensive analyses of the d-excess values and HYSPLIT model results further showed that the precipitation in summer and autumn was mostly related to the water vapor in the Pacific and Indian Oceans carried by the southeast and southwest monsoons, while the precipitation in winter and spring came from a wide range of sources, including the water vapor from monsoons, westerly zone, polar airflow and local evaporation. The findings of this study help to complete the theory of the atmospheric moisture cycle in South China and are also of practical significance for local water resource management and flood control and disaster alleviation.
Key words：southern metropolis; atmospheric precipitation; stable H-O isotopes; HYSPLIT model; moisture sources
EARTH AND ENVIRONMENT Vol.51, No.2, Tot No.352, 2023, Page 133
