Irrigation induced soil salinisation in the Yanqi Basin, China-modelling approaches and possible solutions:
Intensive irrigation with river water in the semi-arid Yanqi Basin has caused several environmental problems, the most severe one being soil salinisation. The Yanqi Basin is a typical example for the misuse of water in a semi-arid region. Irrigation has caused a substantial rise of the groundwater table, followed by soil salinisation. Agricultural production can only be maintained by means of over-irrigation.
However, this triggers off a vicious circle, as over-irrigation again contributes to a rising groundwater table, leading to an ever higher salinity and water consumption at a given production level. Conjunctive use of ground- and surface water, as well as an improvement of the efficiency of the irrigation systems are measures that would contribute to both a reduced salt concentration in the Basin itself as well as an increased amount of freshwater in the downstream systems. To evaluate the feasibility and to find optimal solutions, a hydrologic model simulating surface water, groundwater and the coupling between them was constructed.