2017 Sierra Leone mudslides

2017 Sierra Leone mudslides
Landslide SierraLeone August2017.jpg
Mass wasting of mud in Freetown on August 14, 2017
Sierra Leone - Western Area.svg
Location of the Western Area in Sierra Leone where the mudslides occurred (in red)
DateAugust 14, 2017
Time6:30 a.m. GMT (06:30 UTC)
LocationWestern Area, Sierra Leone
Coordinates8°26′2″N 13°13′22″W / 8°26′2″N 13°13′22″W / 8.43389; -13.22278
Cause
Deaths1,141
Homeless3,000
Affected area116,766 m2 (1,256,858 ft2)
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On the morning of August 14, 2017, significant mudflow events occurred in and around the capital city of Freetown in Sierra Leone. Following three days of torrential rainfall, mass wasting of mud and debris damaged or destroyed hundreds of buildings in the city, killing 1,141 people and leaving more than 3,000 homeless.

Causal factors for the mudslides include the region's particular topography and climate – with Freetown's elevation close to sea level and its greater position within a tropical monsoon climate. Those factors were assisted by the generally poor state of the region's infrastructure and loss of protective natural drainage systems from periods of deforestation.

Background

The potential for deadly flooding in Sierra Leone was exacerbated by a combination of factors. Freetown, which sits at the tip of a peninsula, was in 2015 occupied by approximately 1 million people.[2] Freetown's topography alternates between thickly wooded and partially deforested mountains.[3] These mountains run along the peninsula parallel to the Atlantic for 25 miles. Freetown's elevation varies from coastal areas which are at or just below sea level to approximately 400 meters (1,300 ft) above sea level.[4]

Freetown suffers from long-term issues involving poor urban development programs. According to Jamie Hitchen of the Africa Research Institute "the government is failing to provide housing for the poorest in society", and when attention is paid to issues such as unregulated construction, it is received only after a crisis.[5] Because a moratorium on housing construction was not enforced, unorganized settlements and municipal works encroached on flood plains, resulting in narrower water passageways.[6] During floods, Freetown's drainage systems are often blocked by discarded waste, especially in the city's poorer communities, contributing to higher levels of surface runoff.[7]

The construction of large homes in hillside areas and unrestricted deforestation for residential purposes weakened the stability of nearby slopes and caused soil erosion.[7] Within a decade leading up to the disaster, Sierra Leone cleared approximately 800,000 hectares of forest cover – the country's civil war, fought between 1991 and 2002, was also a cause of deforestation. The nation's Environmental Protective Agency launched a reforesting mission in the region two weeks prior to the floods and mudslides, which was ultimately unsuccessful.[8]