Agro-ecological geochemistry survey and evaluation of Weihai City, Shandong Province, China

The main results of agro-ecological geochemical survey and evaluation of Weihai are introduced. Generally, the geochemical environment quality is good. The type I and II soil accounts for 97.49% of the total survey area, and the typeⅢ and typeⅢ-soil which mainly locates in the parts of Rushan City and Yaxi Township of Rongcheng City only accounts for 2.51%, Cr、Ni、Cu、Cd are the key elements exceeded quality standard. Most elements or indexes of shallow groundwater are below the natural background concentration, and the concentration of Cd、Fe、 NO2- and the total hardness in parts of shallow groundwater samples are over the drinking water standards. This shallow groundwater is not suitable for drinking. The existent ecological geochemical problems in this area are mainly: the pH value of soil is low in the hilly area, and the top soil has the developing trends into the strong acid and strong alkali, which will increase heavy metal element activation; the soils of coastal area are barren; the nutrition level of N, P and organic matters are usually in the lack level; the heavy metal pollution is serious in top soil of Rushan City and densely populated township, including Hg Cd Pb and Zn. The combined effect of high geological background, acidic surface environment and the industrial pollution are the main reasons cause higher levels of heavy metals.