Variation in The Quality of Irrigation Water With Increasing Distance From Sea: A Case Study in Kaluthawala Villege Of Batticaloa

Abstract

Ground water is the source for irrigation in the coastal area of Batticaloa district. Intensive crop cultivation is occurring in some villages in the coastal areas namely, Kaluthawalai, Chettipalayam, Kaluwanchikudi etc. and farmers have no idea about the quality of irrigation water they use. Considering the general problems with irrigation water in the coastal area, the present investigation was carried out with a view of assessing the irrigation water quality closer to the seashore in Kaluthawalai village. Irrigation watersamples werecollected during July toAugust2008. Samplings were done four times in 2 weeks interval and those were analyzed for chemical parameters. The quality characteristics of water collected at different locations were compared and correlated with the distance from the sea. Results showed that the pH greater than 7.0 indicating the alkaline nature and vulnerable to irrigation. The EC values increased with the increase in distance from the sea but not reached the permissible level. All the samples were under C3 class (EC=0.75-2.25dS/m) according to the electrical conductivity values that indicating the moderate salinity will lead to increasing problem during continuous irrigation with this water. The concentrations of cations in water indicated that Ca was the dominant ion followed by Na and Mg. Total dissolved solids, cation concentration, Sodium Adsorption Ratio (SAR) and Ca/Mg Ratio of irrigation water in the study area were within the tolerant limit. There is non-significant relationship was observed between water quality parameters with the distance from the sea. Further, it is revealed that the groundwater of the study area is likely suitable for irrigation with the management practices against the salinity problem. However, over exploitation of ground water may lead to salt water intrusion near coastal area of the village