Investigation of chemical change in water quality and spatial modeling with GIS mapping: A case study from Beşgöz Lake in Konya Province of Türkiye

Abstract

In this study, Beşgöz lake in Sarayönü district of Konya province, located in the Central Anatolia Region of Türkiye, was chosen as the study area. Rehabilitation work was carried out in 2020 with the resources of the State Hydraulic Works. The average depth of Beşgöz Lake was increased from 4 m to 8.5 m, and its surface area was increased from 86.000 m2 to 230.000 m2. Beşgöz Lake, located in Sarayönü district, provides water from underground sources at the bottom of the lake. These underground sources come from the gaps in the limestone in the lower parts of the lake. When looking at the geological map, it is thought that there is a connection between Beyşehir Lake and Beşgöz Lake because the land has a calcareous structure. The changes in the water quality parameters of Beşgöz Lake in different periods were examined and spatially modeled using spline interpolation techniques with Arc GIS 10.3.1 program, one of the Geography Information Systems (GIS) software. In order to determine some water quality parameters of Beşgöz Lake, water samples were taken from eight different points representing the lake in 4 different periods (Spring, Summer, Autumn, Winter). Seasonally in the water of Beşgöz Lake, water quality parameters such as pH, Electrical Conductivity (EC), Temperature, Chloride (Cl), Nitrite (NO2), Nitrate (NO3), Sulphate (SO4) Chemical Oxygen Demand (COD), Suspended Solids (TSS), Boron (B) were investigated. As a result of the research, it was found that pH values varied between 7.77–8.42, EC: 268–470 µS/cm, water temperature varied between 6.8–20 °C, Cl varied between 0.139 - 3.9 mg/L, NO2 varied between < 0 00–0.33 mg/L, NO3 varied between < 0.00 - 4.13 mg/L, SO4 varied between 0.057 − 18.4 mg/L, COD varied between 5–32, TSS: 0.60 - 31.8 and B varied between 0.05–0.093 mg/L. As a result of the study, it was seen that the water quality of Beşgöz Lake, which is the subject of the research, is class I and potable water quality.