Study On The Classification Method Of Priority Area For Soil Environmental Protection Around Water Sources

As Notice of the General Office of the State Council on the issuance of recent arrangements for the work of soil environmental protection and comprehensive management(2013 No.7)was issued,it has been the new focus for current management work of water sources that establishing priority area for soil environmental protection around water sources,according to the quality of the soil environment.As the relevant work is still in the initial stage with scarce experience in our country,it is urgent to put forward a set of practical and feasible methods for the classification of priority area.In this paper,exploratory work was completed in 4 parts:(1)The definition of priority area for soil environmental protection around water sources was proposed:it is the land region delineated in the surrounding of water sources with the target to guarantee the safety of drinking water and with the means of protecting the soil environment.The technical procedures of the classification of priority area include the investigation of environmental status,selection of evaluation factors,construction of evaluation system and determination of classification criteria.Besides,the classification should be based on the different levels and the spatial distribution of soil environmental protection pressure around water sources.(2)From the aspects of water pollution status,soil environmental quality,environmental fragility and pressure of pollution sources,we comprehensively describe the evaluation factors on the protection of soil and drinking water,providing the theoretical basis for the determination of the most influencing indicators as well as the assessment of environmental pressure.(3)The specific implementation methods of classification of priority area were expounded through a case study of the drinking water source in Shunde channel,Foshan City.With the help of literature research and field survey,the main environmental problem was identified as heavy metal pollution.And then 7 indicators containing the pollution degree of heavy metals in soil and sediment,soil physicochemical properties,water sensitivity,vegetation coverage,the type and distribution of pollution sources were used for calculation,in terms of aim,regional,comprehensive and feasibility principles.(4)The environmental pressure indexes of various regions were obtained and the classification of priority area was completed for soil environmental protection around water sources in Shunde channel,applying Analytic Hierarchy Process(AHP)and Geographical Information System(GIS).According to the values of pressure indexes,the priority area of soil environmental protection was determined and divided into polluted zone,risk zone and safety zone,respectively,accounting for 6.37%,60.90%and 32.73%of the total area.Lecong,Longjiang and Leliu towns represented the most parts of polluted and risk zones,with the wide distribution and long-term development of the manufacturing industries like furniture,plastics and building materials.Targeted and differentiated strategies were also put forward in the end.Based on the above research,this paper established classification method of priority area for soil environmental protection around water sources.The method focuses on the recognition of the influencing environmental problems and the evaluation of soil quality.The research results are expected to provide theoretical and technical support for the protection and sustainable utilization of soil environment around the water sources.