Changes of sedimentation environment inferred from fallout radionuclides and physical properties of sediment in Sun Moon Lake, Taiwan

Abstract

This study describes the impact of dam construction at Sun Moon Lake, Taiwan, on lacustrine sedimentation. Analyses of the physical properties of sediment cores show that the surface sediment has two layers: the post-dam layer consisting of high-density, organic-poor sediment, and the underlying pre-dam layer consisting of organic-rich sediment. After correction for decay since initial deposition, the estimated concentration of excess 210Pb in the pre-dam layer was much higher than that in the present surface layer. These results indicate that the dam construction had a large impact on supply of 210Pb and the sedimentation environment in this lake.