Using QUAL2KW and AHP as Decision Making Tools in Surface Water Quality Assessment and Management: A Case Study of Cikapundung River, Bandung, Indonesia

Abstract

The Cikapundung river has faced substantial water pollution in recent decades, primarily due to rapid population growth. This study aimed at using QUAL2KW and AHP as decision making tools in surface water quality assessment and management. The study applies to a combination of qualitative and quantitative methods included primary  and secondary data collection. Water quality data  collected from six monitoring stations representing upstream, midstream, and downstream of  river. Secondary data collected from Government regulations, reports, and similar studies. Parameters such as pH, temperature, conductivity, DO, TSS, ammonia, nitrate, and phosphate simulated using QUAL2KW and validated against field observations. RMSPE of calibrated and validation data showed nearly the same values for  pH, temperature, DO, conductivity, nitrate,  ammonia, and TSS (i.e., 4%, 8%, 9%, 24%, 26%, 45% and 58% respectively). The scenarios based simulation conducted and the findings indicate that the implementation of integrated pollution reduction measures represented by scenario 3 (90% reduction) provides the most effective strategy for improvement of water quality. Analytical Hierarchy Process (AHP) used for prioritizing strategies for surface water quality management. AHP tool ranked Upgrading Wastewater Treatment Plants with high composite weight of 0.31 and  Community-based monitoring and clean-up activities with weight  of 0.253. The integrated use of QUAL2KW and  AHP tools  provides an effective decision-making support tool for sustainable surface water management.