沧州市优质果品产区土壤中碘的空间变异特征

Spatial Variation of Soil Iodine in High-quality Fruit Producing Area of Cangzhou

以沧州市优质果品产区泊头、沧县和献县3县表层土壤(0～20cm)全碘为研究对象,利用地统计与GIS技术相结合的方法研究了该地区土壤中全碘的空间变异特征。结果表明沧县和献县表层土壤中全碘数据呈正态分布,符合指数模型,泊头表层土壤中全碘数据经对数转换后符合高斯模型。沧县和献县表层土壤全碘具有较强的空间相关性,说明受气候、土壤母质、地形、土壤类型等自然结构性因素影响较大;泊头表层土壤全碘具有中等的空间相关性,说明由人类活动等随机因素引起的空间变异起很大作用。采用Kriging最优插值法得到了3县表层土壤全碘含量的空间分布图,结果表明研究区内3县表层土壤全碘的空间分布不均匀,主要受当地的水文地质地形影响,河流两岸及低洼地带全碘含量较高,反之则低,而某些地区全碘含量由于受到人类活动的影响也表现出局部的异常性。

Taking the total contents of iodine in surface soils（0 –20 cm） of high-quality fruit producing area in Botou,Cangxian,Xianxian three counties of Cangzhou city as studied object,the spatial variations of iodine were analyzed by geostatistics and GIS techniques.The results showed that iodine in Cangxian and Xianxian were of normal distribution and fitted with exponential model,while iodine in Botou fitted with Gaussian model after logarithm conversion.Iodine in Cangxian and Xianxian showed higher spatial correlation,which suggested the greater influences from natural structural factors,such as climate,soil parent material,topography and soil type;iodine in Botou showed medium spatial correlation,which stated the greater influences from random factors,such as human activities.By adopting the most excellent Kriging method,the spatial distribution maps of iodine in the three countries were edited,the results showed that the spatial distributions of iodine in three countries were asymmetrical,it was mostly affected by hydrology,geology and topography.Iodine contents in both shores of the rivers and low-lands were higher than other areas,whereas iodine contents in some areas showed partial abnormality owing to the influence of human activities.