The Variability of Groundwater Mineralization in Minqin Oasis

Abstract

Based on spatial analysis function of GIS, spatial heterogeneity of groundwater mineralization and its relationship with land use dynamics in Minqin oasis of Shiyang river watershed were studied using semivariogram and ordinary Kriging of geostatistics in this paper. Spherical model was fit for both data sets in 1987 and 2001, and the results of an F-test showed that the difference was significant. The spatial heterogeneity of groundwater mineralization caused by random factors was very small, and that caused by automatic factors accounted for 99.9%. Results of mapping of groundwater mineralization by Kriging and comparison with landscape maps in the same period show that: the area with groundwater mineralization lower than 3.0 g/L decreased from 75.26% in 1987 to 58.54% in 2001, and the area with groundwater mineralization greater than 4.5g/L is distributed in Huqu, northern part of Minqin oasis. Also, area of farmland with groundwater mineralization greater than 3.0 g/L increased from 7.03% in 1987 to 14.32% in 2001.