Data Evaluation in Selected Basins in Türkiye

Abstract

Studies on monitoring water quality and quantity in the receiving environment in Türkiye have gained momentum in the last decade. In recent monitoring activities, simultaneous monitoring of micropollutants as well as conventional parameters is very valuable. There are deficiencies in the integrated evaluation of these recently produced data, revealing their statistical relationships, comparing basins, and the suitability of the data for index studies. In this thesis, data produced for 10 basins were compiled to form a set, and relationships between the data were examined to evaluate the basins. In the first section of the thesis, all data were evaluated, investigating differences in the Limit of Detection (LoD) and measurable concentration values. As a result of the evaluations, it was found that there was an average difference of 727 times between the LoD values and that the average measurable concentration value was approximately 20%. There are 343 parameters below the average, and the probability of evaluating these parameters is low. There are 296 parameters with a measurable concentration value below 5% and 73 parameters below 1%. Furthermore, the study identified parameters commonly observed across all basins, including Alcalinity, Antimony, Arsenic, Suspended Solids, Copper, Barium, Beryllium, Biochemical Oxygen Demand, Boron, Zinc, Dissolved Oxygen, Iron, Bis(2-Ethylhexyl) Phthalate, Fluoride, Fluoranthene, Silver, Electrical Conductivity, Chemical Oxygen Demand, Cobalt, Manganese, Nickel, Nitrate Nitrogen, Nitrite Nitrogen, pH, Selenium, Titanium, Total Nitrogen, Total Phosphorus, Total Kjeldahl Nitrogen, Chromium, Total Organic Carbon, Total Hardness, and Vanadium. Bis(2-Ethylhexyl) Phthalate and Fluoranthene are micro-pollutants observed in all basins. For all data, it was found that all reports for 3-Hydroxycarbofuran, Azadirachtin, Azinphos-ethyl, Cyflufenamid, DDT isomers, Diclofop-methyl, Hexabromodiphenyl ether, Pencycuron, Pymetrozine, PBDE 183, Triflumizole, Nitrate, Sulfur, Dichlorobenzene, Tribromodiphenyl ether, and Chloronitrotoluenes were < LoD, making it impossible to evaluate these parameters. In the second stage of the thesis, relationships between parameters showing micro-pollutant characteristics were revealed using multivariate statistical analyses. Pearson correlation analysis, cluster analysis, principal component analysis, ANOVA analysis and factor analysis were conducted. As a result of the statistical analyses, parameters with high correlation (r>0.7) were identified, and it was found that the data had 11 components. Additionally, it was determined that the basin factor affected all parameters, while seasonality affected only some parameters. As a result of all the studies, a decision tree methodology has been developed for use by decision-makers in parameter selection. In the third part of the thesis, the water quality status of the basins was determined using the Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI), and the results were compared with River Basin Management Plans (RBMP). When all basins were evaluated together, according to CCME WQI results, 1% of all points were classified as "excellent", 1% as "good", 11% as "fair", 35% as "marginal", and 52% as "poor". Comparison studies with RBMP revealed that CCME WQI data were highly consistent with RBMP data and that CCME WQI is applicable.