Soil salinization process in a semi-arid wetland basin: the effect of reservoirs on a shallow aquifer

A study of the relationships among water load in reservoirs, the artesian conducting layer and water in the top soil was based on chemical and isotopic characteristics. The conceptual model attempts to describe the hydraulic effects of surface reservoirs on a shallow semi-confined conducting layer that results in salinization of the top soil. The results indicate that there was only limited infiltration from reservoirs into the top soil layers with probably no penetration of water into the conducting layer. Reservoirs, however, formed hydraulic barrier that increased the artesian pressure in the conducting layer. A linkage between leakage from the artesian layer into the top soil and a decrease in drainage capacity was found. The role played by surface reservoirs in the build-up of artesian pressure in the shallow conducting layer as derived from environmental tracers is emphasized.