Assessment and Mapping of Heavy Metals Pollution in Tea Plantation Soil of Zhejiang Province Based on Gis

According to the 2nd grade (pH<6.5) of GB1516-1995, Inverse Distance Weighted interpolation method of GIS, single and Nemeorow's synthetic pollution indexes were used to assess and map heavy metals pollution in tea plantation soil of the primary tea producing area in 12 counties of Zhejiang Province. It was indicated by using exploring statistics and assessment map of single pollution index that contamination of Cd was the highest, followed by Ni, As and Zn, while the contaminations of Cr, Cu, Hg and Pb were all zero; almost all of the tea soil were unpolluted by Cr, Cu, Hg and Pb, and few was slightly polluted by As, Cd ,Ni and Zn.Moreover, it revealed on the assessment map created from Nemeorow's synthetic pollution indexes that 160 samples were located in the safety domain, 12 samples were located in the precaution domain and only 7 samples were slightly polluted; up to 93% of the whole study area was belonged to safety domain, 6.5% was the precaution domain, whereas only 0.50% area was the slightly polluted domain.