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CURGO after the disaster. © MSF

The mudslide caused plenty of damage. © MSF

Clean-up efforts after the disaster. © MSF

Clean-up efforts after the disaster. © MSF

Jan Moeyersons is head of the Geomorphology and Remote Sensing section.
His latest mission (8-13/07/2012): to finalise and present a report on the protection of a clinic against water risks in Kabezi (Burundi), in the company of Philippe Trefois.

CURGO

The Kabezi 'Centre for obstetric and gynaecological emergencies' (CURGO) is a clinic run by Doctors Without Borders (MSF) that treats women suffering from pregnancy-related complications. On average, the clinic handles 5 deliveries daily – meaning that at least ten lives are saved there every day.

Natural disaster

On 8 January 2010, a mudslide swept through CURGO, causing enormous damage. In late 2011, MSF contacted Jan Moeyersons and asked him to study the causes of the mudslide and suggest how to prevent another one from happening.

Reasons for the mudslide

The section’s expertise in water risks made it possible to pinpoint the reasons behind the mudslide very rapidly. CURGO is located close to a 3-metre-long bridge crossing the Nyabage river, which spans 20 m at its widest point, flowing from the mountain. Landslides in the mountain created a sort of natural dam to the river. When this dam was breached, a large mass of water and mud headed the clinic’s way. Rocks and mud began to bottleneck at the bridge, and kept accumulating until the mud finally spilled over and destroyed the clinic.

Possible solutions

Several solutions were proposed. First, it is possible to prevent landslides from happening. The landslides occur because of the river’s steep vertical incision into the mountain. This unstable configuration triggers landslides. Ideally, ‘radical earthmoving’ such as is done in Rwanda should be done, with terraces at a slight reverse gradient on the mountain. The river would then be stabilised, and no more landslides would happen.
Since this solution cannot be adopted immediately, another solution is to construct a bridge as long as the river’s width (20 m) to avoid the bottleneck effect. However, work can only begin in 5 years at the earliest.
In the meantime, an early warning system was proposed. Movement sensors can be placed in the river at a distance of 4 km upstream from CURGO. These sensors emit a signal when rocks with a diameter of 1 m or more begin to shift. Based on the speed at which these rocks can move, CURGO staffers have between 15 and 20 minutes to evacuate the centre. Evacuation exercises are already being conducted, and the clinic can be evacuated in 4 minutes.
An alternative would be to construct a dike around the centre. A visit at the Delft University of Technology (Netherlands) should provide more data on this possibility.

The report was presented to Burundian authorities in Bujumbura, as MSF would like to turn over CURGO to the authorities but without the clinic being a poisoned chalice.

A bottleneck effect at the bridge crossing the Nyabage river caused the mudslide at CURGO. J. Moeyersons © MRAC