Modelling of water quality in upper Citarum River

Upper Citarum river water quality management that wasconducted b PROKASIH (Clean River Program) was aimed to re­duce effluent loads in upper Citarum watershed. However, the river water quality condition in upper Citarum river is not improved yet by dense population and industrial development. Optimizing manage­ ment strategies is necessar then for improving river water quality.In order to support the river water qalit management, a computer model of river water quality has been developed. The model has an important role in optimizing the management policy in such complex water quality system in upper Citarum watershed. The model con­ sists of tree sub-models. Those are runoff-hdrograph by a reformed tank model, estimation of discharge load (COD, BODS, T-N, T-P, and NHJ using loading-factor method, and runoff-polltegraph by a reformed tank model The models ware calibrated to the water quality and daily discharge data series of river of upper Citarum (at Nan­ jung station]. The computer models show the run-hdrograph and run-pollutograph models tend to follow the observed data of the river of upper Citarum