Influences of correcting ion pairs and activity on classification of groundwater for irrigation purpose in Makhmur province

This study was done during the dry and wet seasons of 2024, which included water chemical analysis for 36 wells in Makhmur province is located between the longitude (43° 58’34” E and 43°37, 82” E latitude 35°26’70” N and 35° 15’ 56” N), then classified depending on some international classification systems before and after correcting ion pairs and activity. The main results were as follow:
Depending on Electrical conductivity and sodium adsorption ratio values of water samples the water for (9 ,1,22 and 4) wells had (C₃S₁, C₃S₂, C₄S₁and C₄S₂)) classes before correcting ion pairs and activity respectively; while after correction, the water for (9,1,16, 8, 1 and1) wells had (C₃S₁, C₃S₂, C₄S₁, C₄S₂, C₄S₃ and C₄S₄) classes. Relying on water salinity potential (SP) values, before correcting ion pair and activity the water for (9,3and 24) wells had good, moderate, and bad category. It means correcting ion pairs and activity caused conversion the water for (4) wells from bad to moderate class. On the other hand, relying on sodium adsorption ratio values water for (14,17 and 5) wells had non-restriction, slight to moderate and severe restriction of use respectively before correction. While after correcting ion pair and activity the water for (12,19 and 5) wells had non-restriction, slight to moderate and severe restriction of use respectively that caused change the water for two wells from class one to class two. While depending on bicarbonate concentration the water for two wells changed from slightly-moderate class to non-severe restriction of use after correcting ion pairs plus activity. In general, in most cases correcting ion pair and activity causes decrease in risk of saline water for irrigation due to conversion the water classes towards the better classes. The main results explained the role of ion pairs and activity in conversion the water from class to another then decrease the salinity risk for irrigation use in most cases.