Estimating flushing time in Citarum River Estuary, Indonesia by using empirical and numerical methods

This study aims to estimate the value of flushing time in Citarum Estuary, West Java, Indonesia. Calculation of the value of flushing time on this research uses empirical and numerical methods. Flushing time value is influenced by physical parameter values that exist in the estuary, such as tides, salinity, river discharge, and topography of Citarum River Estuary. The data is sourced from the observation conducted by Oceanography Department, Bandung Institute of Technology in March and September, 2013. The flushing time value during the wet season is shorter than the value of the flushing time during the dry season, it is influenced by discharge of river water that occurs in two seasons. Flushing time in the wet season using empirical method is 2.20 hours while that using numerical method is 4.75 hours. In the dry season the result of calculation using empirical method is 8.25 hours whereas that using numerical method is 17.75 hours.