Fig. 5: Evolution of the population exposed to UG expansion.
From: Mapping urban gullies in the Democratic Republic of the Congo
a, Population living less than 100 m away from a UG, within the potential expansion zone of a UG and within the expected expansion zone (Methods, ‘Estimating the exposed population’). Transparent zones indicate the estimated overall error range of ±40% (Methods, ‘Uncertainty assessment’). b, Causes of increases in population exposure between 2010 and 2023 (Methods, ‘Estimating the exposed population’). ‘Population increase’ refers to population growth within hazard zones already present in 2010. ‘Expansion of existing UGs’ refers to increases in hazard zones due to the expansion of UGs already present in 2010. ‘Formation of new UGs’ refers to increases in hazard zones due to UGs that were not present in 2010 but have formed and expanded since then. As errors on the population estimates across different years are unknown, the uncertainties on the individual causes of exposure increase could not be quantified (Methods, ‘Uncertainty assessment’).
