Exploring a Water Balance Method on Recharge Estimations in the Kilombero Valley, Tanzania
Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
Simple models that require little input data and are easy to use is the ideal case within hydrology. Basic water balance principles often represent such approaches as the method on rainfall-runoff relationship developed by Sutcliffe et al. in India in 1981. That was tested for the Kilombero Valley in Tanzania in order to estimate the recharge to the soil and sub-surface systems. Measured annual runoff in the streams was compared to the seasonal net rainfall to give the difference as potential recharge. This was done for five separate sub-catchment where the hillslope catchments gave a smaller proportion of the net rainfall to occur as surface runoff compared to the valley-catchments. Due to the difference in hydrologic setting from the original model site in India to the Kilombero Valley (e.g. a wetland and stream type), the soil moisture recharge could not be estimated. Also, corrections are needed to the data preparation process and the state of the original stream flow data is questionable. Thus, the results were interpreted as an indication on how the water resources could be moving in the system. An explaining theory that captured the difference between the landform types is mountain system recharge. That implied that all surplus rainfall generated in the mountains has a potential to eventually recharge the groundwater. The method tested, though its simple general concepts, could not alone give satisfying results for the Kilombero Valley system. However, this study convey the importance of continuous exploration of methods to describe the environment in a simplified way.
Place, publisher, year, edition, pages
2013. , 18 p.
water balance, kilombero
Oceanography, Hydrology, Water Resources
IdentifiersURN: urn:nbn:se:su:diva-92345OAI: oai:DiVA.org:su-92345DiVA: diva2:638613
Lyon, Steve, Senior Lecturer
Jarsjö, Jerker, Senior Lecturer