Effect Of Water Resource On Soil Salinization Of Oasis In The Lower Reaches Of Tarim River, China

Abstract

The development of oasis in the lower reaches of the Tarim River has been impeded due to serious soil salinization and water resource shortage. To examine the effect of water resource on soil salinization, we analyzed the effects of surface water resource, groundwater depths and quantity on soil salt content based on the field monitoring. The results showed that the relationship between quality of surface water and soil salt content in 0-50 cm was significantly positive, but not to the salt content of the 50-100 cm layers. The soil salt content also closely related to the groundwater depth, of which 0-50 cm layers surface soil salt content declined with the increasing groundwater depth, and the change of 0-20 cm soil salt content was biggest. When the groundwater depth was shallower, the soil salt content was high with high surface concentration, which showed a “T” distribution, and soil salt content decreased with the increasing soil depth, in the order 0-20cm>20-50cm>50-100 cm. With the groundwater depth increasing, soil salt loads reduced and showed a “rhombus” distribution, which mainly accumulated in the middle layer, in the order 20-50 cm > 0-20 cm > 50-100 cm. When the groundwater depth was more than 6m, the hardness, total dissolved solids (TDS) and conductance of the groundwater as well as the soil salt loads distribution appeared sharply changes. So, the critical groundwater depth for condensing salt content in groundwater and changing the soil salt loads distribution was 6 m.