北京市平原区土壤类金属砷质量分数分布特征研究

基于变异函数理论、经典统计分析、地统计分析以及单因子污染评价方法,以北京市平原区农用地为研究对象,针对不同功能分区、种植模式和母质类型,设置不同土壤深度(0~25cm,25~50cm),对土壤中类金属As的质量分数、水平和垂直分布特征及影响因素进行分析.结果表明:整体上,0~25cm,25~50cm土层As块基比值均小于50%,结构性因素占主导,随着土壤深度增加,随机性因素减少;不同深度土壤As质量分数水平空间分布变化趋势基本一致,平谷区As质量分数均值最高,其污染指数达1.54.不同功能区土壤As质量分数差异性无统计学意义(p0.05).种植模式对0~25cm土壤类金属As质量分数影响有统计学意义(p0.05),对25~50cm As质量分数的影响极有统计学意义(p0.01),果园土壤As质量分数存在累积现象;不同母质类型对0~25cm,25~50cm土壤类金属As的影响有统计学意义(p0.05),钙质岩类风化物母质下的不同土壤深度As质量分数均最高.

Distribution Characteristics of Mental-like Asin Soil of Beijing Plain

Based on the theory of variance, classical statistical analysis, geostatistical analysis and single factor pollution evaluation, the agricultural land in plain area of Beijing was selected as the research object. According to different functional zoning, different planting patterns and different parental types, setting up different soil depth (0-25 cm, 25-50 cm), and the horizontal and vertical distribution characteristics and influencing factors of As content were analyzed. The results were as follows:On the whole, 0-25 cm, 25-50 cm soil As block ratio was less than 50%, structural factors play a dominant role. With the increase of soil depth, the randomness factor was reduced. The spatial distribution of As in different depths was basically the same, and the average content of As in Pinggu was the highest, its pollution index was 1.54. There was no significant difference in soil As content between different functional areas (p<0.05). There were significant effects of different cropping patterns on As in 0-25 cm soil (p<0.05), and the extremely significant effects in 25-50 cm soil (p<0.01). The As content in the orchard soil had a certain accumulation of As; There were significant effects of different parent material types on arsenic in soils of 0-25 cm and 25-50 cm(p<0.05), and the mass fraction of As in the different soil depths of calcareous rocks was the highest.