Groundwater Quality and its Suitability for Irrigation at Al-Wafra Agricultural Area in the State of Kuwait

Abstract

The Wafra area is located in the southern part of the State of Kuwait constituting about 47% of the State’s total agricultural area. The expansion in Wafra area from 11.25 km2 in 1973 to 199.2 km2 in 2010 has led to excessive pressure on groundwater resources. The objective of this study was to examine the quality of the groundwater in terms of suitability for irrigation pertaining to specific quality standard indices. To achieve this, water samples were collected from 31 wells in Wafra Area. The samples were analyzed for salinity, cations, anions, and some heavy metals. Results indicated that the values of total dissolved salts )TDS(, electrical conductivity )EC(, chlorine )Cl-(, calcium )Ca+2(, and sodium )Na+( detected in water samples did not satisfy Kuwait, and GCC standards. The study revealed that 68% of the wells were highly saline while the rest were moderately saline according to FAO standards. According to Simsek and Gunduz )2007(, the water can be considered moderately suitable for irrigation. According to Richard )1954( standards the water is of type C4-S4 )highly saline and sodic( and not suitable for irrigation according to AOAD standards. Piper diagram and regression and correlations analysis indicated that sodium and chlorine are the dominant cations and anions. The analysis also revealed that the concentration of cadmium )Cd+2( in all the tested wells was higher than the standard concentration range of 0.01 to 0.05 mg/l and to a lesser extent nickel )Ni+2( and manganese )Mn+2(, violating the permissible limits. The results also showed an increase in total dissolved salts with time from 6984 ppm in 1989 and 7930 in 1998, reaching an average of 9211 by 2010. The study recommended encouraging adoption of modern agriculture techniques and reuse of treated wastewater, to protect soil and groundwater from salinization and to promote sustainable agricultural production in Wafra area as well as periodical check for heavy metal concentrations specially cadmium in groundwater.