I would like to find out from the GIS community what is the best available datasets for Africa for generating catchments and catchment characteristics for hydrology. I'm looking for the most detailed and correct datasets including Rivers, DEM, Lakes, etc. I've used the SRTM 90m DEM to generate catchments to calculate catchment characteristics. I'm currently working on a project that needs to look at multiple bridge sites on a railway line. I used the SRTM 90m DEM initially to generate the catchments, but due to the cell size, the position of the actuall bridge sites cant be modelled correctly. I battled and eventually was able to download the ASTER GDEM 30m DEM sheets for the area, unfortunately the sheets are full off artifacts (i.e. lines) which won't make it suitable to use to generate catchments. Any assistance in finding more suitable data sources for Africa would really be of assistance.
Regards
