Abstract:

 Based on the study of chronology and geochemistry of Cd in sediments of the Dongting lake area, we have established an ARIMA model of Cd and Cd/Ca in Quaternary and Holocene period respectively, and discussed Cd evolutionary regularity according to the fitted value and predicted value of the model The results revealed that the Cd evolution has remarkable periodicity of ecogeochemistry cycles, and is correlated with the climate change of alternative cold and warm Cd/Ca is changed with climate, from which the evolutionary history of regional ecogeochemistry can be inferred The changes of Cd and Cd/Ca are basically simultaneous, which showed that the change of Cd is mainly a natural evolution Cd in sediments will rise in the next 30 years and then tend to decrease From the regularity of ecogeochemistry indexes and global environment variation, it is concluded that the natural environment is the dominant factor affecting the Cd deposition

Key words:

Key words: Quaternary; riverlacustrine deposits; Cd; Cd/Ca; time series analysis; ARIMA model; ecogeochemistry