关中盆地地下水氟含量空间变异特征分析

Characteristics of Spatial Variation and Distribution of Fluoride Content of Groundwater in Guanzhong Basin

对关中盆地潜水系统进行取样分析,取得了225个潜水样本的氟含量,运用地质统计学中的变异函数工具对所取得的数据进行了分析。结果表明,区内地下水中氟含量服从对数正态分布,空间相关性为11.0%,即空间相关性很强;说明结构性因素对于影响区内地下水中氟含量空间分布起主导作用,而随机性因素对其分布的影响是次要的。在此基础上,利用Kriging方法绘制出关中盆地潜水氟含量的空间分布图,并分析探讨了区内潜水中氟含量的分布规律及形成原因。

225 phreatic water samples from Guanzhong Basin are analyzed to get their fluoride concentrations. The method of geostatistics is used to study the characteristics for spatial variability and distribution of fluoride content of groundwater in Guanzhong Ba- sin. The results are as follows： （1）The fluoride content of groundwater in the basin shows a lognormal distribution. （2）The calcula- tion of semivariogram reveals that the fluoride content of groundwater in the area has a strong spatial correlation. （3） Kriging method is then used to generate the distribution map of fluoride content of groundwater in the area. From the map, it can be found that the fluoride content of groundwater in the basin is high as a whole and that in northern part is generally higher than the southern part as well as the middle and eastern parts generally higher than the western part. This paper discusses the meteorological, geological, geo- morphological, hydrogeochemical and other possible factors which causesuch a situation.