Water Quality Modeling of Langat River Basin Using HEC-RAS

This study evaluates the water quality of Langat River, Malaysia by analyzing the concentrations of biochemical oxygen demand (BOD) and ammonium-nitrate (AN) and their relationship with rainfall patterns. Water samples were collected from Langat River monthly from 2016 to 2018 and analyzed for BOD and AN concentration. The HEC-RAS program was used to assess the river flow, and the relationship between rainfall and water quality was analyzed. The study found that BOD and AN concentration in Langat River are influenced by rainfall patterns. The highest BOD levels occurred in January and June 2017, while the highest AN concentration level was recorded in January 2017. Both pollutants show a direct relationship with rainfall intensity, with the highest concentration levels occurring in North–East (NE) monsoon season. Strict government policies on pollution prevention and control were found to have reduced the concentrations of both pollutants in the river. This study provides valuable information on the water quality of Langat River and highlights the importance of monitoring and managing water resources to manage water pollution.