摘要：Changes in the intensity of precipitation as a result of global warming are
expected to be especially pronounced in the tropics. The impact of changing
rainfall intensities on groundwater recharge remains, however, unclear. Analysis of
a recently compiled data set of coincidental, daily observations of rainfall and
groundwater levels remote from abstraction for four stations in the Upper Nile
Basin over the period 1999–2008 shows that the magnitude of observed recharge
events is better related to the sum of heavy rainfalls, exceeding a threshold of
10 mm day−1, than to that of all daily rainfall events. Consequently, projected increases in rainfall
intensities as a result of global warming may promote rather than restrict groundwater
recharge in similar environments of the tropics. Further monitoring and research are
required to test the robustness of these findings, but the evidence presented is consistent
with recent modelling highlighting the importance of explicitly considering changing
rainfall intensities in the assessment of climate change impacts on groundwater
recharge.
