How does the way land is used around a river relate to its water quality?

Details

Surface water resources have played a fundamental role in the development of human societies. With different agricultural and industrial activities taking place in the Acacias River basin, this study aimed to analyze how land use influences water quality and identify the main sources affecting river water quality.

The observational sampling study established 12 stations representing different land uses and sampled on three occasions. The National Sanitation Foundation-Water Quality Index (NSF-WQI) was applied to the water-quality evaluation data.

Stations associated with urban centers had higher concentrations of fecal coliforms, biochemical oxygen demand (BOD) and phosphates. Principal components analysis revealed a close relationship between fecal coliforms, phosphates and BOD and organic-matter pollution processes. These processes were probably related to domestic and industrial wastewater discharges and detergents in urbanized areas.

Total dissolved solids and turbidity had the greatest ranges of values. These results agreed with observations from the correlation analysis. Nitrate concentrations were higher at stations 6 and 7, associated with areas under agricultural and industrial influence, including oil palm crops in the basin.

The study describes its findings on the Acacias River as extremely important for the region. It concludes that the river’s self-purifying capacity allows improved water quality in areas where the predominant land use is not associated with human settlements.