Urban gullies are a rapidly growing concern in many tropical cities of the Global South.Various measures are already implemented for their stabilization.However,an overview of these measures and their overall effectiv...Urban gullies are a rapidly growing concern in many tropical cities of the Global South.Various measures are already implemented for their stabilization.However,an overview of these measures and their overall effectivenesss is currently lacking.We aim at addressing this gap by documenting existing ini-tiatives to stabilize urban gullies in D.R.Congo and assessing their overall effectiveness.To this end we conducted extensive field campaigns in Kinshasa,Kikwit and Bukavu and combined our terrain obser-vations with data on gully expansion rates(derived from series of satellite imagery).In total,we char-acterized present and past stabilization initiatives for 398 urban gullies.For 69 of these gullies,the effect of a specific measure on gully expansion rates could be estimated.Results show that for the large ma-jority of gullies,various measures have been implemented.Yet,these are mainly ad-hoc measures installed by the affected population.More structural measures based on larger engineering works were observed for only 20-30%of gullies.The huge efforts invested in the installation of measures strongly contrast with their overall low impact Among all strategies,only the deviation of runoff resulted in significantly lower expansion rates after installation.The numerous initiatives that rely on the sparse means available seem to have limited effects.This does not imply,however,that they are completely ineffective and should be abandoned.Based on our findings,we formulate recommendations for further research on how to effectively prevent and stabilize urban gullies,taking into account the difficult environmental and socio-economic context.展开更多
文摘Urban gullies are a rapidly growing concern in many tropical cities of the Global South.Various measures are already implemented for their stabilization.However,an overview of these measures and their overall effectivenesss is currently lacking.We aim at addressing this gap by documenting existing ini-tiatives to stabilize urban gullies in D.R.Congo and assessing their overall effectiveness.To this end we conducted extensive field campaigns in Kinshasa,Kikwit and Bukavu and combined our terrain obser-vations with data on gully expansion rates(derived from series of satellite imagery).In total,we char-acterized present and past stabilization initiatives for 398 urban gullies.For 69 of these gullies,the effect of a specific measure on gully expansion rates could be estimated.Results show that for the large ma-jority of gullies,various measures have been implemented.Yet,these are mainly ad-hoc measures installed by the affected population.More structural measures based on larger engineering works were observed for only 20-30%of gullies.The huge efforts invested in the installation of measures strongly contrast with their overall low impact Among all strategies,only the deviation of runoff resulted in significantly lower expansion rates after installation.The numerous initiatives that rely on the sparse means available seem to have limited effects.This does not imply,however,that they are completely ineffective and should be abandoned.Based on our findings,we formulate recommendations for further research on how to effectively prevent and stabilize urban gullies,taking into account the difficult environmental and socio-economic context.
