Temporal variation of significant soil hydrological parameters in the Yutian oasis in Northwest China from 2001 to 2010

Abstract

In this paper, the temporal variation and causes of groundwater depth, total dissolved solids (TDS), and NO3 −-N in groundwater, as well as salt and water in soil profiles in the Yutian oasis, northwest China from 2001 to 2010 have been studied. The results showed that: (1) during this period, the NO3 −-N in the groundwater showed an increasing trend with the order of mean values at 2010 > 2005 > 2001, while the average values of the groundwater depth and TDS in groundwater were both in the order of 2010 < 2005 < 2001. (2) The geostatistical analysis showed that in 2001, 2005 and 2010, the spatial distribution of the water table and TDS contents in groundwater, and salt and water in soil profiles all declined when going from the northern to the southern region of the oasis, while the NO3 −-N contents in groundwater declined when going from the center to the periphery. (3) Correlation analysis showed that in these three periods, there were obvious correlations between the water table and the TDS in groundwater, the groundwater depth, and the salt content in soil (0–60 cm), and the water table and the water content in soil (0–60 cm). (4) This work found that during recent years, with the influence of natural and human factors, the water table, the TDS, and NO3 −-N in groundwater were significantly increased. At the same time, there was an increase trend in the salt content and a decrease trend in the water content in soil profiles, resulting in increased degree of salinization in the oasis. This deserves much attention and reasonable planning of economic development in the oasis and strict control of the use of water resources should be inspired.