Subsurface evaporation at the Mirzachul area in Uzbekistan

Аннотация

The development of unsustainable irrigation schemes in the region Mirzachul has had significant environmental and ecological impacts associated with elevated water tables; the abandonment of large tracks of land due to salinization; declining crop productivity andreturns on investments; enhanced salinity levels in irrigation return flows to the two dominant rivers that has had a profound effect on aquatic species and quality of water.The dominant approach adopted by irrigation farmers to mitigate salinity in the region is to apply excessive amounts of water to salt affected fields in order to leach salts below the effective root zone. It has been estimated that between 20 – 25% of the annual available surface water in the region is used for leaching. The application of additional surface waters to fields has resulted in the development of elevated water tables that effectively exacerbates the problem through the mobilization of further salt