Assessing the quality of groundwater in Bulgaria for irrigation purposes - a spatial approach

This study analyzes groundwater quality and its suitability for irrigation purposes. Various 2D models have been created using GIS to illustrate the groundwater chemistry of Bulgaria's hypergenic zone (Ca²⁺, Mg²⁺, Na⁺, SO₄^2–, Cl^–, EC, and TDS), focusing on groundwater with active water exchange. These models are based on data from the Executive Environment Agency of Bulgaria from 2015 to 2019. The author has constructed 2D models representing several indicators of water quality suitable for irrigation, including the Sodium-adsorption ratio (SAR), Magnesium hazard ratio (MHR), Potential salinity (PS), and the (Mg²⁺/Ca²⁺) and (Na⁺/Ca²⁺) ratios. The identified irrigation indicators provide a regional perspective on groundwater quality across Bulgaria. On a macro scale, average values for the individual indices classify shallow groundwater primarily as suitable for irrigation, with a small percentage deemed unsuitable. Its potential to create issues related to soil infiltration capacity and structural degradation, assessed based on salinity and sodium (or alkaline) hazards, is primarily classified as low.