Distribution Characters of Element Cd in Different Physiognomy Type Alluvial Soils of Yangtze River(Gong'an Segment)

The results of multi-purpose geochemical survey show that there exist high value distribution of heavy metal Cd in alluvial soil along the Yangtze River.This paper chooses the alluvial soil of Gong'an segment of the Yangtze River,located in Hubei Province,as the research object.It discussed the distribution character of element Cd in different physiognomy type topsoils(0~20 cm),and also mainly researched the relationships between distribution character of vertical and horizontal of Cd and content fluctuation of OrgC,pH and clay(silica-alumina ratio).The study results show that:①The distribution of Cd in shallow surface soils is characterized as: The content of Cd in lacustrine deposit,alluvial lacustrine and alluvial-diluvial low-lying plain is 1.4 to 1.8 times as high as in alluvial-diluvial high valley flat and alluvial-diluvial high bank physiognomy areas.②The content variation of Cd in horizontal distribution was controlled by clay primarily and OrgC secondly.The variation of OrgC was major factor that affected the content variation of Cd in vertical distribution.