Groundwater hydrochemistry

The results indicate that the concentration of major ions and total hardness are normal in all the boreholes of the four Qa''s ( Qa'' Balasan Qa'' Samah Qa'' Sherah and Qa'' Asawad) showed and drinkability while they are abnormal in Wadi Almawaheb it was not found their drinkability due to the impact of wastewater from Dhamar city. Hydrogeological evaluation of groundwater indicates a dominance of cations Ca2+> Na+> Mg2+> K+ and anions HCO3-> Cl- >SO4- and the dominant type of groundwater are 48% mixed cations and anions 30% Ca2 +-HCO3- 15% Na+ -Cl- -SO42- and 7% Na+- HCO3- and respectively this indicates that the type of groundwater is a dissolution of a mixture of dolomite CaMg(CO3) gypsum (CaSO4 2H2O) and Halite (NaCl). The irrigation evaluation parameters show that the water is usable for agriculture in Qa'' Sherah Qa'' Samah Qa'' Balasan and Qa'' Asawad except in Wadi Almawaheb and according to the US Salinity classification the studied samples are classified as 75% C2-S1 1.7% C2-S2 15% C3-S1 5% C4-S1 and 3.3% C4-S2