Subsurface evaporation at the Mirzachul area in Uzbekistan

Abstract

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 and returns 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. The studies clearly showed the areas with the vegetation improvement and continuous degradation. The results of the studies could be used by policy makers to specify further activities within improving water management plan in the MIP or similar areas. The evaluation of the impact of interventions was conducted with help of RS/GIS analyses. For this purpose, long-term Landsat satellite images were used. Field studies were initiated at two sites: from July 2013 subsurface evaporation basin studies were initiated