The Multi-target Regional Geo-chemical Characteristics And The Soil Environmental Quality Assessment In Wuwei Area Gansu Province

On multi target regional geochemical survey of Wuwei region in Gansu province,we have identified that clearly which are the distribution and allocation of the element geochemical characteristics in the survey area. The measured administrative regionsare Minqin, Gulang and liangzhou which under the Wuwei City, Gansu Province, where the survey area is totaling6000km2. We carried it out in accordance with the gridded when we are in the wild soil work. The sampling density on collecting surface soilsamples is one point per square kilometer which corresponding to the sampling depthof0-20cm. We are ccording to a point/4km2collect the deep soil samples,and the sampling depth of1.5m. In which a total of6060and1568are collected respectively from the deep samples and the surface samples. At last, we analysis54,and the Analysisof density is a point per4km2on the surface soil samples, and respectively a point per16km2on the deep soil samples. The main results achieved in the project are as follows:1、Through the multi-target geochemical suney in wuwei area,gansu province,the geochemical character of the varied soil types and the parent soil material’s elements in the working zone has been figured out.The survey also counts the background value of the surface soil and the geochemical base line valne of deep soil.2、According to the national standard a comprehensive assessment to the soilenvironment at the working zone has been finished.And the results argues that thereare7.26%healthiest soil,58.15%less healthier soil,5.02%middle middle class soiland12.93%,substandard soil,in the working zone.3、Workers classify the soil in a geochemical method scientifically.And thesoil’s geochemical environment area has been divided.They select agriculturalnutritious element(P、 SiO2、CaO、MgO、Al2O3、N、K2O)， beneficial traceelements(B、Se、Mn、Mo、TFe2O3),environmental effect elements (Cd、As、Cr、Hg、Ni) geological environment elements (Pb、Zn、Ag、Au)、workers put theseelements to be indicators of mapping and the other elements,distribution as areference.Besides the regional geological features soil types and the land exploitation londition has been taker under consideration in dividing.4、According to geological background,soil types,geological background,soiltypes,geomorphic units,workers compares the element’s character of varied types.Theconvergence and divergence trend of elements,the combination of distribution have allbeen discussed.this fills a gap in this field.geochemical area.based on these points,arich area,a lacking area,a background area have been dividied.