Abstract:

Based on the data of daily δD，δ18O of precipitation in Changsha station from Jan.2010 to Feb.2011.we have analyzed the variable characteristics of δD，δ18O of precipitation  under the synoptic timescale.The results indicated that there was significantly negative correlation of δ18O in precipitation with precipitation amount,vapor pressure,temperature and relative humidity under the synoptic in Changsha,and the variation of  δ18O in precipitation had significant precipitation amount effect，humidity effect and antitemperature effect.The meteoric water line  was 〖WTBZ〗δD=838δ18O+173〖WTBZ〗 in Changsha, which was similar to  the line under the monthly timescale according to GNIP（Globe Network of Isotopes in Precipitation）.But the slope and intercept of Changsha was larger than GMWL (Globe Meteoric Water Line),which revealed that it had the  climatic characteristics of humid and rainy in Changsha.These results had great impacts on revealing stable isotopic characteristics in East Asian monsoon and interpreting pale climate studies