Stable isotopes in precipitation in relation to the meteorological factors in Yangtze river basin

Abstract

Analysis is conducted on the temporal and spatial variations of stable isotopic composition in precipitation, using the data of IAEA/WMO sampling stations, in Yangtze river basin. The correlations between δ18O in precipitation and air temperature/amount of precipitation are analyzed at individual stations and in the whole valley on monthly or annual scales. There is notable amount effect, the distinct inverse relationship between δ18O and precipitation, on monthly scale in the Yangtze valley and at the selected stations except Chongqing. Compared with monthly scale, the positive correlation between δ18O and air temperature is more marked on annual scale. The interannual variations of δ18O reflect the change of large-scale climate and environment, and are mainly controlled by large-scale weather conditions.