Hydrological Modelling for Tropical Catchments

The British University in Egypt, Faculty of Engineering

Sherouk City, Cairo-Ismailia Road, Cairo, Egypt

The assessment of the complex hydrological characteristics in the upper Citarum catchment,

West Java, is reported. The effects of population growth and land use changes on the state

water resources and its availability are also included. The validity of rainfall data of the

hydrological system has been statistically checked for trends, independency, and mean and

variance stability. The classic Thiessen Polygon method has been used in estimating the areal

rainfall intensities over the catchment, while storm events with arbitrary return periods have

been derived from the frequency analyses. The Pearson III distribution has been selected to

simulate the rainfall-surface runoff relationship, for giving the most reliable results. The flood

analysis software HEC-1 has been employed to carry out the numerical simulations for a

recorded flood event in 1994. The Cikapundung sub-catchment has been chosen, as a case

study, for calibrating the hydrological simulations. The Soil Conservation Service method has

been used in simulating and calibrating the runoff hydrograph, for various composite curve

number values. Due to the complex features of the catchment, and due to lack of adequate

land use data, extensive field measurement studies are needed for realising sound predictions.