The variations of stable isotopes(δD and δ~(18)O) in the precipitation in Baotou area

Stable isotopes(δD and δ18O) in the precipitation contain the information of the water cycle,which can be used to identify the mechanism of the formation and evolution of water resource.According to the isotope and meteorological data(1986-1992) in Baotou station,we discussed the variations of the hydrogen and oxygen stable isotope(δD and δ18O) in precipitation and the relationships with the temperature and rainfall.The results show that the value of deuterium excess(d) was higher in winter and lower in summer.The weighted mean deuterium excess in the Baotou area closed to the mean value(10‰) of the global.The value of δ18O was higher in summer than in winter,and the temperature effect in this area was significant,and the precipitation amount effect was obvious only in the summer period(April-September).The equation of the local meteoric water line in Baotou area was δD = 6.4*δ18O-4.07,and the semi-arid climate could be identified by comparing with the local and global meteoric water line.