Mudflows occur when the soil and regolith become saturated with water, usually after heavy rainfall. They mix together to form mud, which then moves rapidly downslope. Mudflows are the fastest type of mass movement, with speeds of up to 100 km per hour.
Case Study: Mocoa Mudslide, 2017 Caribbean Sea PANAMA Cartagena VENEZUELA
Pacific Ocean
C O L O M B I A Bogotá
Cali Mocoa ECUADOR PERU BRAZIL
On Saturday, 1 April 2017, a devastating mudslide hit the city of Mocoa, Colombia. Rain had begun to fall late on the Friday evening, and in only two hours had reached levels of more than 127 mm – the level of rainfall normally experienced in a month.
At least 254 people were killed, 400 were injured and 200 were missing. More than 1,100 soldiers and police officers were called in to help dig people out in seventeen affected neighborhoods.
Colombian president Juan Manuel Santos declared an ‘economic, social and ecological (environmental) emergency’ and pledged 40,000 million pesos (€11.5 million) in aid for the area.
1. Describe how a mudflow occurs. 2. Describe the impact of the mudflow in Mocoa. In your answer, mention one economic and one social consequence.
