山东省黄河下游流域土地质量地球化学评估及方法研究

摘要

BasedonthegeochemicaldataofthesurfacesoilobtainedfromthedownstreambasinoftheYellowRiverinShandong,the authorsusedtheregularlandqualitygeochemicalassessmentmethods,putforwardtheassessmentvalueindexsystemoftheworkarea, determinedtheweightsofallassessmentindexlayers,andthencompletedthelandqualitygeochemicalassessmentoftheworkarea. Studiesshowthat,asthesoilsourceintheworkareaisrelativelyuniform,mostoftheassessmentunitclassificationsalwaystendtobe thesamedespiteusingdifferentassessmentindexsystems,upto80%landofthewholeregioncanbeassignedtoexcellentgrades,and landsoftwo-endsgradesareoftensmallerandfragmented.Theassessmentclassificationcanreflectthelevelsofthesoilfertilityand healthyelementsand,duetotherarenessofthesoilthatexceedstheenvironmentqualitystandard,theclassificationsimplyindicates therelativemeritsofsoilenvironmentalquality.Theassessmentresultcanprovideguidancefortherationalutilizationoflandresources andprovidethedatabasisandreferenceforthelowergradestagegeochemicalassessmentwithinthisregioninthefuture.%　　利用土地质量地球化学评估的基本方法，以黄河下游流域山东境内6．4万km2冲积平原区表层土壤区域地球化学调查数据为基础，提出了区内进行评估的参评指标体系，确定了各评估指标层的权重，进而对区内土地质量进行了系统的地球化学评估。研究发现，由于区内土壤物源的相对单一性，在不同参评指标体系下，大部分评估单元的分等始终趋向一致，其中优良等级土地占全区的80％，两端分等土地往往面积较小且分散。评估分等的意义以反映土壤综合肥力和健康指标的高低为主，由于区内土壤环境质量超标比例极小，分等仅指示土壤环境质量的相对优劣。该评估成果可为土地资源的合理利用提供指导，并为今后区内开展的次级地球化学评估工作提供了基础和参照。