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

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 Basin.The results are as follows: ①The fluoride content of groundwater in the basin shows a lognormal distribution.②The calculation 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,geomorphological,hydrogeochemical and other possible factors which causesuch a situation.