Résumé
Dry drainage is thought to be a potential approach to control soil salinity. This study took the Hetao Irrigation District as an example and evaluated the effectiveness of dry drainage by using remote sensing, a conceptual model and a field experiment. Archived remote sensing images from 1973–2006 were used to delineate the temporal and spatial change of soil salinity. The conceptual water and salt balance model was used to evaluate the role of dry drainage in removing excess salt from the irrigated land. The field experiment was performed to get field validation and give more accurate estimation. The results show that dry drainage did contribute to remove excess salt from the irrigated land and succeed in controlling soil salinity in the Hetao Irrigation District. It can be taken as an alternative approach in (semi-)arid area where artificial drainage is not applicable.