Temporal and Spatial Variations of Bottom Sediment Characteristics around the Tama River Mouth in Tokyo Bay, Japan

摘要

This study investigates the temporal and spatial variations in therncharacteristics of bottom sediments around the Tama River mouth.rnSediment samples were taken from 28 points every 3 months betweenrnMay 2007 and October 2009, including the Tama River mouth area andrnan offshore site with a water depth of about 24 m. The collectedrnsediment cores were sliced into four layers by depth (0–1 cm, 1–2 cm,rn2–4 cm, and 4–10 cm) and the samples were analyzed, which includedrndetermining grain size distribution, water content, ignition loss, andrnoxidation–reduction potential. The data showed that the sediments atrndifferent monitoring sites responded to the impact of the typhoonrelatedrnflood that struck the Tama River in early September of 2007rnquite differently. Drastic changes in water and organic content werernobserved, especially at the deep offshore site, due to the typhoon.