Evaluation of Irrigation Water Quality of Aksaray Region By Using Geographic Information System

Abstract

In this study, the quality of irrigation water was determined in Aksaray region which is one of the most important agricultural lands of Turkey, the facts causing pollution were specified and the precautions that should be taken were discussed. Within the scope of this study, 38 samples were taken from the water of 24 wells, 4 dams, 9 ponds and 1 source water. In order to use the data more effectively, irrigation water quality index map of Aksaray region including the results of the samples (EC, SAR, B, Cl-, NO3-, HCO3- and pH) was prepared by using Geographic Information System (GIS). According to irrigation water quality index map, all surface water sources were found to be suitable for irrigation with high and medium irrigation water quality index. EC, SAR, Cl, HCO3 values were found as high in Acipinar well and Aratol well regions whereas EC and Cl values were high in Taspinar well region. It was determined that underground water sources have low irrigation water quality index value along in the range of Taspinar region and Tuz Lake whereas they have generally medium irrigation water quality index value. The soil being heavy-texture and salty structure in the region and the level of ground water being high were caused by lack of adequate drainage system. For this reason, good and adequate drainage system should be configured in order to provide no increase in salt accumulation in the soil, to get an opportunity for more appropriate land use and to increase the yield per unit area.