Tracing Anthropogenic and Environmental Impacts on River Water Quality: Sustainable Perspective on Contrasting Environments

This paper represents a comparative study of two rivers, namely, the Andarax River, Spain, and the River Liffey, Ireland, considering different climatic conditions and human activities and their influences on most water quality parameters. Water samples collected from different sampling sites along each river were analysed for field parameters such as the pH, dissolved oxygen (DO), total dissolved solids (TDS), electrical conductivity (EC), and nitrates, phosphates, and potassium (NPK) levels of floodplain soil. Spatial changes were assessed using various geostatistical methods such as the Pearson correlation, multiple linear regression (MLR), and water quality index (WQI). The Andarax River had a higher TDS and was turbidly higher with EC due to agricultural activities and the naturally higher evaporation in the semiarid climate. In contrast, DO levels varied widely in the River Liffey, especially in reaches under the influence of urbanisation and agricultural runoff. The artificial surface and agriculture are the strongest negative determinants of water quality in both rivers, with artificial surfaces contributing about 35.72% to the DO variation. The WQI identified the water quality in the Andarax River as poor to very poor in certain locations, while the River Liffey exhibited a good to medium quality overall, although with localised degradation in areas of high human activity. The results of this study are important for developing targeted remedial measures in diversified climate conditions and a customised water sustainability plan to address the challenges of each area.