caa a22 4500 445814780 CHVBK 20180317145223.0 cr unu---uuuuu 170323e20111101xx s 000 0 eng 10.1007/s10040-011-0779-1 doi (NATIONALLICENCE)springer-10.1007/s10040-011-0779-1 Groundwater/surface-water interactions on deeply weathered surfaces of low relief: evidence from Lakes Victoria and Kyoga, Uganda [Elektronische Daten] [Michael Owor, Richard Taylor, Christine Mukwaya, Callist Tindimugaya] Interactions eau souterraine/eau de surface sur des surfaces profondément altéréesde faible relief: cas des lacs Victoria et Kyoga, Uganda Little is known of the interactions between groundwater and surface water on deeply weathered landscapes of low relief in the Great Lakes Region of Africa (GLRA). The role of groundwater in sustaining surface-water levels during periods of absent rainfall is disputed and groundwater is commonly excluded from estimations of surface-water balances. Triangulated piezometers installed beside lake gauging stations on Lake Victoria and Lake Kyoga in Uganda provide the first evidence of the dynamic interaction between groundwater and surface water in the GLRA. Stable isotope ratios (2H:1H, 18O:16O) support piezometric evidence that groundwater primarily discharges to lakes but show further that mixing of groundwater and lake water has occurred at one site on Lake Victoria (Jinja). Layered-aquifer heterogeneity, wherein fluvial-lacustrine sands overlie saprolite, gives rise to both rapid and slow groundwater fluxes to lakes which is evident from the recession of borehole hydrographs following recharge events. Darcy throughflow calculations suggest that direct contributions from groundwater to Lake Victoria comprise <1% of the total inflows to the lake. Groundwater/surface-water interactions are strongly influenced by changing drainage base (lake) levels that are controlled, in part, by regional climate variability and dam releases from Lake Victoria (Jinja). Springer-Verlag, 2011 Groundwater/surface-water relations nationallicence Groundwater monitoring nationallicence Stable isotopes nationallicence Africa nationallicence Uganda nationallicence Groundwater recharge/water budget nationallicence Owor Michael Department of Geology, Makerere University, P.O. Box 7062, Kampala, Uganda aut Taylor Richard Department of Geography, University College London, Pearson Building,Gower Street, WC1E 6BT, London, UK aut Mukwaya Christine Water Resources Management, Ministry of Water and Environment, P.O. Box 19, Entebbe, Uganda aut Tindimugaya Callist Water Resources Management, Ministry of Water and Environment, P.O. Box 19, Entebbe, Uganda aut Hydrogeology Journal Springer-Verlag 19/7(2011-11-01), 1403-1420 1431-2174 19:7<1403 2011 19 10040 https://doi.org/10.1007/s10040-011-0779-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10040-011-0779-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Owor Michael Department of Geology, Makerere University, P.O. Box 7062, Kampala, Uganda aut NATIONALLICENCE 700 1- Taylor Richard Department of Geography, University College London, Pearson Building,Gower Street, WC1E 6BT, London, UK aut NATIONALLICENCE 700 1- Mukwaya Christine Water Resources Management, Ministry of Water and Environment, P.O. Box 19, Entebbe, Uganda aut NATIONALLICENCE 700 1- Tindimugaya Callist Water Resources Management, Ministry of Water and Environment, P.O. Box 19, Entebbe, Uganda aut NATIONALLICENCE 773 0- Hydrogeology Journal Springer-Verlag 19/7(2011-11-01), 1403-1420 1431-2174 19:7<1403 2011 19 10040 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer