Groundwater hydrology and hydrochemistry research implemented over the high productive aquifer system located in the lower Ruzizi river plain, North of Tanganyika lake, led to the preparation of piezometric maps that identify major groundwater flow directions from the mountains North of Bujumbura towards the SW. Physico-chemical parameters distribution revealed increasing salinity towards the South-West, where the concentrations largely exceed WHO standard limits for both human supply, animal farming and agriculture. Overall, the groundwater in the other parts of the aquifer characterize for good quality standards. Still it is worth to stress that the research focus was not on WASH, hence contamination due to leaking latrines and unmanned waste disposals may turn to be relevant at local scale. Being in a data poor region, an interesting contribution of the research attains at the monitoring quality data being reported and sampling wells locations derivable from published map.
A preliminary groundwater flow model developed with MODFLOW in steady state conditions well align with above evidences and provide a first attempt to quantify the exchanges between the surface water drainage network and the aquifer system. Model calibration refinement in transient conditions is envisaged once time series of groundwater levels will be available. Overall groundwater withdrawal in the region looks like limited, with a large preference for surface water or use of springs.
Another interesting contribution of local scale relevance attains at historical flooding phenomena in the urban area of Bujumbura. The mapping of such a major geo-hydrological risk evidence can be a good reference point for analyzing water occurrence frequency as derived from remote sensing products as the JRC GSW (Global Surface Water) as well as the higher resolution Copernicus Sentinel-1 derived Google product DW (Dynamic World).
Scientific articles can be found here:
https://www.researchgate.net/publication/381474247_Water_Geochemistry_a…
https://www.researchgate.net/publication/356669833_Groundwater_Flow_Mod…