Study On The Classification And Evaluation Of Regional Soil’s Buffering And Filtration Funcions

With the intensification of soil pollution，research on soil bufferingand filtration function can be paid more and more attention and lie importance oncombating soil pollution, protecting groundwater sources, developing science andtechnology agriculture as well as promoting eco-building. Method of documentationand expert consultation are employed to determine evaluation indexes. Expert scoringand AHP are employed to determine the index weight. Both single-factor andcomprehensive evaluation are employed to evaluate total function and sub-function.Overlay integration method is used to transmit information from total function andsub-function. Research content and conclusion are as follows:(1)Soil buffering and filtration function can be classified into soil buffering andfiltration capacity to acid and alkali, soil buffering and filtration capacity to heavymetal, soil decomposing capacity to organic pollutants.(2) Evaluation of soil buffering and filtration capacity to acid and alkali: takingZhengzhou as study area and combining soil facts in Zhengzhou, pH, organic matter,soil texture, clay content, CEC, bulk density and electrical conductivity can beselected as evaluation indicators, establish evaluation system of soil buffering andfiltration capacity to acid and alkali, use powerful spatial analysis capabilities ofArcgis to show the result by figures. Studies indicate that: Surface layer soil bufferingand filtration capacity to acid and alkali is the best of all in northeast part ofZhengzhou and Gouzhao area in the west part while southwest, southeast and Huijiarea in the north part is the poorest. As for soil profile buffering and filtration capacity to acid and alkali, the west part is better than the east one.(3) Evaluation of soil buffering and filtration capacity to heavy metal: pH,organic matter, soil texture, clay content, bulk density, electrical conductivity andenvironmental capacity which can be accommodated can be selected as evaluationindicators, establish evaluation system of soil buffering and filtration capacity toheavy metal, use powerful spatial analysis capabilities of Arcgis to show the result byfigures. Studies indicate that: in the southeast part of Zhengzhou where town Putian is,surface layer soil buffering and filtration capacity to heavy metal is the best whilelarge part area of northwest part is very poor. Conversely, as for soil profile bufferingand filtration capacity to heavy metal, east part is poor while west part is good.(4) Evaluation of soil decomposing capacity to organic pollutants: pH, organicmatter, soil texture, clay content, bulk density, total nitrogen, soil structure and rootscan be selected as evaluation indicators, establish evaluation system of soildecomposing capacity to organic pollutants, use powerful spatial analysis capabilitiesof Arcgis to show the result by figures. Studies indicate that: as for surface layer soildecomposing capacity to organic pollutants, northeast part, northwest part and areabetween Houzhai and Shibalihe in the south are the best town Xushui in the west partand southeast part are the poorest. As for soil profile decomposing capacity to organicpollutants, west part is good and east part is poor.