Spatial and temporal evaluation of the physicochemical quality of domestic/industrial water in the Kırklareli Reservoir (Turkish Thrace)

Abstract

The Kırklareli Reservoir, located in the Meriç-Ergene River Basin, is an important drinking/industrial freshwater resource of the Kırklareli Province. In order to ensure the sustainable use of this important reservoir, its current situation should be examined periodically and evaluated by multivariate analyses. For this reason, water samples were taken between the dates April 2018 and February 2019 at monthly intervals from 3 different stations. The data on the environmental and physicochemical variables (water temperature, dissolved oxygen, pH, salinity, conductivity, total dissolved solids, chlorophyll-a, light permeability, fluoride, chloride, NO2-N, NO3-N, PO4, SO4 and essential/potentially toxic elements) were measured and evaluated according to the classes of surface water quality control regulation of Turkey. The parameters exceeding first-class water quality values (chlorophyll-a, pH, NO2-N, chloride, selenium) were mapped in GIS using the spline integration approach. In addition, the sodium absorbtion ratio, Kelly index values and magnesium ratio, were calculated to evaluate the water quality for agricultural irrigation water standards. The water quality of the reservoir was evaluated using multivariance analyses (Bray–Curtis similarity index, correspondence analyses, Pearson correlation index). As a result, it was emphasized that the use of the GIS approach is a potential useful method for monitoring the sustainable water quality of the Kırklareli Reservoir, which was determined to have an oligomesotrophic character.

Keywords

• water quality
• gis
• environmental variables
• multivariate analyses