Abstract:

7Be which is one of the most investigated radionuclides in the atmosphere has wide applications in meteorology and geochemistry.It also has been a useful tracer for documenting soil erosion rates over much shorter timescales.In order to find the suitable time of soil erosion by using 7Be tracer in Nanjing region,monthly atmospheric deposition samples of 7Be were collected from January 2010 to December 2011.Deposition samples were experimented to obtain residual samples which was followed by measurement with a HPGe detector for 7Be.Deposition fluxes and seasonal variation pattern of atmospheric deposition of 7Be were analyzed.The results showed that the depositional fluxes of 7Be ranged from 066 to 1449 Bq/(m2·d) and a mean value was 444 Bq/(m2·d),annual average depositional fluxes were 1 62178 Bq/m2.The seasonal variation of depositional fluxes of 7Be showed double peaks,higher flux value was in late winter and early spring,another higher flux value was in summer.The fractor of precipitationnormalized depositional fluxes of 7Be were higher value in winter and spring,but the minimum value was in summer.Furthermore,a positive correlation between the 7Be fluxes and precipitation was observed in this study