Spatial variability of the regional shallow groundwater depth and water quality

139 observing points were sampled in Quzhou County in Huabei plain. The depth of groundwater, salt and nitrate content of groundwater were measured. The geostatistics theory was applied to analyze the data. The results indicated that the depth of groundwater showed a normal distribution, the salt content showed a lognormal distribution and the nitrate content showed neither a normal nor a lognormal distribution. The rational sampling number was determined within a given precision at a known confidence level. By the semivariance analysis those observe items were correlated in a given spatial range. The Kriging method was applied to estimate the unobserved points and generate the contour map. These results show some merit in rational using the groundwater resource and preventing soil secondary salinization and the nitrate pollution.