Spatial distribution and genesis of the surface soil’s salinization in Zhaxikang mine area, southern Tibet

Soil salinization in arid, semi-arid and alpine areas has a great impact on regional agriculture, livestock farming industry and geological environment. Based on the environmental geological survey of the Zhaxikang mine areas in Tibet, the spatial distribution of soil salt and its genesis are found out through the systematic sampling analysis of three soil profiles in Sumailang gully. The results show that there is a positive correlation between the soil conductivity and the total amount of water-soluble salts in the same depths of soil layers, and the content of salt ions in the soil vary greatly from the surface to 80 centimeters underground. When the soil layers deeper than 80 centimeters underground, salt content in the soil tends to be stable. Factor analysis further reveals that the salt in soil in studied areas is mainly composed of chloride and sodium ions, and the correlation between them is strong (R²=0.9592). The soil's salinization in studied areas is caused by the high contents of silicon and sodium elements in the Weimei Formation, the delta and fluvial sedimentary environments of Weimei Formation, and the groundwater activities in the areas. The authors suggest that lowering the groundwater level, spraying water to dilute salt contents in the soil, and applying organic fertilizer to the soil, are suitable preventing methods for soil's salinization in arid areas.