Impacts of Agricultural Runoff on Freshwater Ecosystem Health and Water Quality

Agricultural runoff has been recognized as one of the most prevalent non-point sources of pollution affecting the water quality in rivers worldwide. In this study, examine the effects of agricultural runoff on the levels of various water quality indicators in the mixed-use river basin that comprises both crop lands and peri-urban areas. Water samples were taken from twelve monitoring stations spread out in the study river and its tributaries during three periods, namely pre-monsoon, monsoon, and post-monsoon seasons. The parameters investigated include pH, DO, nitrate, phosphate, TSS, BOD, turbidity, and E. Coli Conclusively, the results showed that the quality of water significantly declined during the monsoon season, characterized by nitrate content of 8.7 ± 1.4 mg/L, phosphate content of 0.31 ± 0.07 mg/L, and a higher than WHO guidelines value of E. coli bacteria at over 310 CFU/100 ml. High Pearson correlation coefficients (r > 0.74, p < 0.01) were established between fertilizer application rate and enrichment with nutrients, as well as rainfall intensity and soil erosion. Eutrophication was evident through high phosphate-algal biomass correlations. In addition to this, the effectiveness of the mitigation measures is assessed in a comparative sense, and some of these include riparian buffer strips, constructed wetlands, precision agriculture practices, as well as AI-based systems to monitor such practices. These findings highlight the absolute necessity of watershed management policies that incorporate both agricultural intensification and hydrology.