GIS-Based Mapping and Spatial Modeling of Drinking Water Quality in The Capital City of Turkiye

This study spatially evaluated certain drinking water quality parameters concerning the 2018-2020 period in Ankara, the capital of Turkiye, using Geography Information Systems (GIS) and the IDW (Inverse Distance Weighted) interpolation method. The study examined drinking water samples taken weekly by Ankara Water and Sewerage Administration (ASKİ). Electrical conductivity (EC), turbidity, residual chlorine (Cl), sulfate (SO4-2), iron (Fe), and aluminum (Al) values were analyzed in drinking water samples. In addition, changes in drinking water quality parameters were evaluated over the years using Mann-Kendall and Sperman's Rho tests. The study indicated the following general average value ranges for Ankara province EC: 28.3-134.9 mS/m, turbidity: 0.23-0.71 NTU, residual Cl: 0.38-0.74 mg/l, SO4-2: 12.33-178.10 mg/l, Fe: 4.4-45.4 µg/l and Al: 9.2-85.6 µg /l. In the trend analysis results, it was seen that there was an increasing change in the examined parameters. As a result of the research, it was seen that the water quality of Ankara province was close to the allowed values.