My first experience with hydrological modelling dates from 1991 when I went to Canberra to work with Rob Vertessy. In a two week period, we succeeded in modelling the impact of harvesting of pine plantations in Fiji with the TOPOG model.
The TOPOG model is a physically based, distributed parameter model developed by CSIRO, Australia. It will model hydrology and vegetation growth in microscale catchments (<15 km2). The model has its own web page, TOPOG online, where the manual is published, examples are given and the source code can be obtained. At present, CSIRO does not provide any support for TOPOG anymore.
In Cameroon, Jean Claude Ntonga (IRGM) and I used the LISEM erosion model to simulate erosion from selectively logged rainforest areas. Lisem was developed by the University of Utrecht, The Netherlands. It is based on the PC-Raster GIS environment.
The TOPOG model is presently used in collaboration with Luz Adriana Cuartas (CPTEC), Javier Tomasella (CPTEC), Debora Drucker (INPA) and Ivar Langedijk (VU) and Remko van Diepen (VU student) to model surface and groundwater runoff from the Asu catchment near Manaus.
In the catchment response analysis course of our MSc Hydrology Program we make use of the HBV-light rainfal - runoff model developed by Jan Seibert. The model was also used to simulate runoff from a small catchment in Fiji under pine plantation forest and deforested conditions (Waterloo et al. (2007)
I also maintain several Python programming libraries containing general meteorological, evapotranspiration and rainfall interception functions. These libraries and a basic Python programming manual for hydrologists can be obtained at http://ecohydro.falw.vu.nl/python.