Assessment of Büyük Menderes River (West of the Türkiye) Surface Water Quality with Water Quality Index (WQI), Comprehensive Pollution Index (CPI) and Geographic Information Systems (GIS)

Abstract

In the present study some of the water quality parameters were spatially examined with water quality and pollution indices in the Büyük Menderes River (BMR). In addition, the more effective parameters on the indices were determined among the parameters measured in the study. The measured water quality parameters were detected as WT:16.5-25.9 oC, pH:7.5-9.3, DO:nd-12.2 mgL-1, EC:312-30215 µScm-1, Salt:0.17-19.6 %o, NO2-N:nd-0.31 mgL-1, NO3-N:nd-1.08 mgL-1, NH4-N:0.035-25.2 mgL-1, TP:0.011-7.45 mgL-1, MBAS:nd-7.79 mgL-1 ve COD:nd-128.9 mgL-1. In the present study, several parameters were determined as the second class and third class of water quality according to the Turkish Water Pollution Control Regulation*. WQI value range was determined as from Bad (38.82) to Excellent (92.35), and CPI as from “Sub Clean (0.39) to Highly Polluted (9.62)” in the stream. It was determined that there was no compatibility between WQI and CPI used in determining the environmental risks in the study area. The GIS was found to be effective in interpreting the spatial distribution of the results obtained and in identifying the key areas that require control. Different statistical analyses were used to determine the relationships between variables. In multiple linear regression (MLR) analysis, it was determined that the most critical parameter affecting the indices was NH4-N. The results obtained from WQI and CPI in the present study indicate that anthropogenic activities are effective in the region. *:TWPCR, Quality criteria of inland surface water resources in terms of general chemical and physicochemical parameters by Class