Composition of Hydrogen and Oxygen Isotope in Precipitation and Source Apportionment of Water Vapor in the Wetland Forest Area of Tangpu Reservoir,Zhejiang Province
[Objective]To study the characteristics of hydrogen and oxygen stable isotope in precipitation and the source of regional atmospheric precipitation in wetland forest area of Tangpu reservoir and to provide reference infor-mation for water resource conservation and management by clarifying quantitatively the distribution and transforma-tion of precipitation in the process of hydrologic cycle in the forest ecosystem of the Kuaijishan-Tangpu reservoir transition zone.[Method]In this study,the data of hydrogen-oxygen isotope in 166 atmospheric precipitation sam-ples obtained from July 2015 to July 2017 in the Tangpu reservoir wetland forest were analyzed by using isotope tech-nology to examine the composition of hydrogen and oxygen stable isotope and to clarify the relationship between the composition and environmental factors (precipitation and temperature).The source and migration path of water va-por were determined by simulating the air mass transmission pathway based on backward trajectory method of the HYSPLIT model.[Result]The relational expression ofδD and δ18 O in atmospheric precipitation in the wetland for-est area of Tangpu reservoir wasδD=8.36δ18O+14.92 (R2 =0.966,n=166,P<0.01);the value ofδD in pre-cipitation ranged from -147.52‰to 2.71‰,with the average value was -38.13‰±27.61‰;the value ofδ18O ranged from -19.05‰to -1.17‰,with the average value was -6.34‰±3.24‰,and the values changed sig-nificantly among seasons.The value of excess deuterium (12.61‰)was higher than the global average (10‰), and a seasonal pattern of excess deuterium in atmospheric precipitation with low value in wet season and high value in dry season was found.The"temperature effect"was not obvious whereas the"precipitation effect"existed signif-icantly.[Conclusion]The meteoric water line of the wetland forest is different from the global meteoric water line and China meteoric water line,The values ofδD andδ18 O in atmospheric precipitation follows obvious seasonal vari-ation in this area.The seasonal change of the water vapor sources of atmospheric precipitation is obvious.It is con-cluded that the meteoric water vapor is mainly from the inland areas in dry season (from October to April of the fol-lowing year),while it mainly comes from the western Pacific and the Indian Ocean in wet season (from May to Sep-tember)according to hydrogen and oxygen isotopic value in precipitation,excess deuterium,and the results of traj-ectory simulation.
meteoric waterwater sourceprecipitation effectstable hydrogen and oxygen isotopeswetland forest area of Tangpu reservoir
NETL
NSTL
万方数据
维普
