Lack of hydrological information of the most basins in Tanzania increase uncertainties in understanding hydrological processes in the basin, and consequently leads to risks decision making related to significant water resources development plans and climate change adaptation. The lack of hydrological information also is coupled with uncertainty related to the predictions of future climate and land use change. Some of the gaps can be filled using rainfall-runoff modeling, which results can be used to generate reliable information to enable decision making and planning for water resources management. This paper discusses the results of applying a semi-distributed rainfall-runoff model which was established for the Little Ruaha Sub-Basin, using the available historical data, with a goal of understanding processes of runoff generation and the inherent uncertainty related to data. Issues of water resources assessment in the basin and approaches used to address them, and some directions for future research are discussed. There are challenges associated with the quality of data for model set-up and understanding of the model structure. Despite these challenges, there remain many opportunities to improve the methods used for water resources assessment and management within the basin.
Part of the book: Achievements and Challenges of Integrated River Basin Management