Effect of Oasis Hydrological Processes on Soil Salinization of Tikanlik Oasis in the Lower Tarim River

Based on the monitoring data of soil salt content,quality of surface water and groundwater in the lower reaches of the Tarim River,the effect of hydrological processes of surface water and groundwater on soil salinization was analyzed.The results showed that there was evident positive correlation between degree of mineralization of surface water and salt content in 0-50 cm soil,but the relationship between degree of mineralization of surface water and salt content in 50-100 cm soil was not evident.Soil salt content was closely related to groundwater depth.And the salt content of 0.50 cm soil decreased with the increase of groundwater depth,especially 0-20 cm soil.The soil salt content was higher and showed a T-shaped distribution pattern when the groundwater depth was lower,but the highly aggregated salt content presented a decreasing trend with the increase of soil depth.On the contrary,the changes of soil salt content showed a diamond-shaped distribution pattern and soil salt content at intermediate layer was higher,when the groundwater depth was higher.The results also showed that the turning point of both groundwater mineralization and soil salt content distribution was 6.0 m.So 6.0 m was the critical groundwater depth to accelerate salt aggregation and stop accumulating soil salt content.