What Freetown's mudslide teaches us about urban climate

By Caroline Fouvet

Floods can have large-scale and devastating consequences. The mudslide that happened in Freetown, Sierra Leone, several weeks ago is a striking example of urban devastation. Over 1,000 people lost their life after days of torrential rains collapsed a hillside in Regent, 15 miles east of Freetown. In August, Sierra Leone received as much rainfall as Canada does in a year. Exploring the causes of this tragedy provides a basis to grasp the challenges posed by rapid urbanisation and climate change.

Sierra Leone belongs to Sub-Saharan Africa, which is one of the world’s fastest urbanising regions, triggered by strong population growth, 2.2% per year in Sierra Leone, and rural flight. In their search for better infrastructure and economic opportunities, Sierra Leoneans converge toward Freetown, where they try to settle. Consequently, capital cities such as Freetown are quickly sprawling, at the expense of their inhabitants’ safety.

However, the capital’s expansion leads to more constructions, which are often illegal and built on hazardous land that is vulnerable to weather impacts. Deforestation is an exacerbating factor for landslide risk, since trees and forests have an important role in preventing them, “not only by reinforcing and drying soils but also in directly obstructing smaller slides and rock falls”, according to the Food and Agriculture Organization. Moreover, the population was not prepared to face a mudslide, that had previously never occurred at this location.

As climate change will compound extreme weather events, vulnerable urban areas are increasingly exposed. In developing countries, urban resilience and risk management measures are necessary to avoid wider socioeconomic inequalities. In Freetown for instance, wealthier residents can afford to move to higher altitudes while already economically deprived inhabitants are left exposed to the floods’ consequences.

Preparing cities to extreme weather events would enable to avoid large-scale catastrophes like the one that struck Freetown this summer. The Mayors’ Task Force on Climate Change suggests several leads on this issue, and highlights that local governments “play a vital role in financing and managing basic infrastructure”, and should mainstream risk reduction into urban management. Early warning and evacuation procedures for example should be implemented and could drastically lower the number of casualties.