乌鲁木齐蔬菜主产区土壤镉污染评价及空间变异分析

采用土壤污染指数法与GIS相结合的方法对乌鲁木齐蔬菜主产区四个乡镇土壤镉元素含量状况进行评价,结果表明:部分土壤存在镉污染,其中六十户乡最为严重,其次为四十户乡,进一步采用经典统计学和地统计学方法对该地区土壤镉含量空间变异特征进行研究,结果为:六十户乡、四十户乡达中等变异水平,青格达湖乡、安宁渠镇属弱变异。半方差函数计算结果说明:六十户乡土壤镉空间相关性弱,块金值/基台值(C0/C0+C)>75%,变程为17.6m,表明六十户乡土壤镉污染主要由人为活动引起,可能为农田采用污水灌溉或过量施用含镉磷肥。安宁渠和青格达湖乡不存在镉超标土壤,四十户乡数据不存在半方差结构,无法用地统计学的方法研究,需进一步尝试其它方法。

The Evaluation of the Cadmium (Cd) Pollution and Spatial Variability of Vegetable Plantation Soil in Urumqi

The evaluation of the cadmium (Cd) pollution in vegetable plantation soil in Urumqi was studied through the method of index coupled with Geographic Information System (GIS).The results showed: Partial soils have cadmium pollution,among which Liushihu village is the most serious. The spatial variability of this region soil cadmium (Cd) was researched using classical statistics and geostatistics method.The results showed: the variation of soil cadmium (Cd) in Liushihu and Sishihu villages were not significant;Based on semi-variogram, the spatial variation correlation in Liushihu was negative.(C0/C0+C)>75%, effective range was 17.6 m, this result showed that the cadmium pollution of Liushihu village is aroused mainly by man-made or applying the farmland with too much cadmium phosphate fertilizer.