Abstract: To further understand the groundwater dynamics in the oasis of the lower reaches of the inland river basin, taking the Minqin Oasis as an example. Firstly, statistics description of the groundwater depth inter-annual scale changes was based on the field survey data from 1999 to 2013; Then 12 potential influence factors of groundwater depth was extracted by the principal component analysis (PCA) method, and the grey correlation analysis (GCA) method was utilized to analyze the sensitivity degree between each influenced factor and groundwater depth. The result showed that: (1)The groundwater depth of the whole oasis showed a rising tendency year by year, whereas there were obvious differences in different regions and periods; (2)The sensitive degree of these correlated factors to the groundwater depth from high to lower in turn as the amount of chemical fertilizer consumption, area of the agricultural plastic mulch films covered, annual mean temperature, total area of cultivated land, population size, planted area of cash crops, effective irrigation area, area of forests, annual precipitation, evaporation, power consumption in agricultural production, amount of large livestock.

Key words: groundwater depth, influence factors, PCA, GCA, Minqin Oasis