乌鲁木齐市米东区农田土壤汞含量及空间分布特征

The Characteristics of Spatial Distribution of Hg Content in the Farm Lands in Midong District of Urumqi City

利用地理信息系统(GIS)及地统计学方法,对米东区农田土壤Hg含量进行空间变异特征分析。结果表明:米东区土壤Hg含量范围为0.050.28 mg/kg,平均值为0.11 mg/kg,未超过《国家土壤环境质量标准》(GB156182-1995)二级标准限值,是乌鲁木齐市农田土壤背景值的2倍;土壤Hg具有较好的空间变异结构,符合球状分布模型;土壤Hg的变程较小(为0.205km),基底系数为50%,属中等空间自相关,说明其在研究区域的空间变异既有来自结构性因素(土壤母质、地形等)又有来自随机因素(灌溉、施肥、耕作措施等)的影响;研究区土壤Hg含量呈中部低两边高的分布规律。

Geographical information system（GIS）combined with Geostatistics was applied to determine the spatial distribution of heavy metal Hg contents in the farmlands from Midong of urumqi.The results showed that： The soil Hg content was in the range of 0.05~0.28 mg/kg,and the average content of soil Hg was 0.11 mg/kg,and it is below the GradeⅡstandard of the National Environmental Quality Standard of two for Soil（GB15618-1995）;and it is two times of Urumqi city agricultural farmland soil background values.Soil Hg has better spatial variance structure,which conformed with the spherical model.The range of soil Hg was smaller（0.205 km）,the base coefficient was 50%,belong to moderate spatial autocorrelation which showed that spatial variation in the study area were affected by the impact both of structural factors（soil parent material,topography,and so on） and by random factors（such as irrigation,fertilization and tillage practices）.The Hg content in soil in the study area was low in the middle part and high in both sides.