Research on characteristics of hydrogen and oxygen isotopes of precipitation in Taiyuan area

The study on the characteristics of hydrogen and oxygen isotopes of precipitation is the basis of researching water cycle by use of isotopic technology. For the aim of revealing the stream source of rainfall,local meteoric water line and evaporative effect during process of rainfall,the paper analyzed the characteristics of hydrogen and oxygen isotopes in precipitation according to observed data. The results show that contents of isotopes in precipitation possesses remarkable season variation due to the impact of monsoonal climate; the large range of D-excess values indicated that air humidity of water vapor sources area varies in larger range; the precipitation in research area mainly come from ocean. The evaporation of surface water has hardly influence on local rainfall; the slope of Local Meteoric Water Line( LMWL) is less than that of Global Meteoric Water Line( GMWL),but it is larger than Evaporative Line( EL),which indicated rainfall occurred certain evaporation in process of rainfall dropping. The results can provide a basis for the study of circle between groundwater and surface water in this region.