Catchment water quality model: sensitivity analysis and parameters estimation

Investigations on water quality parameters are required to protect the aquatic environment and to determine appropriate management options for water quality issues. Usual practice of water quality investigations are performed through separate models in isolation, which can lead to inconsistencies and significant bias in the investigations. As a first step to develop a comprehensive integrated catchment-stream water quality model, a catchment water quality model was developed. The developed catchment water quality model can continuously simulate runoff water quality for different water quality parameters i.e. TSS (Total Suspended Solids), TN (Total Nitrogen), TP (Total Phosphorus). For pollutants build-up in the catchment one of three different pre-defined functions (Power, Exponential and Saturation) can be selected. For pollutants wash-off one of three different functions (Power, Rating-curve and Exponential) can be selected. Each function is defined by one/more parameters. This paper presents sensitivity of rainfall on runoff water quality and parameters estimation under different scenario.