30 March 2023
Buriticupu: a town with a chronic gully and landslide problem in Brazil
Buriticupu is a town in municipality in Maranhão in Brazil, located on a plateau with steep slopes, founded in 1994. Its population is about 73,000 people. Reuters has a very nice video about a chronic landslide problem that is affecting the town, with the issues rapidly escalating over the last year:-
Google Earth imagery (the town is at [-4.327, -46.457]) shows that the town has landslide problems on many slopes -some reports suggest 26 different locations. The image below is one of the worst affected areas, as captured in 2014, before the problem became too serious:-
This is the same site in July 2022:-
I have created a slider to allow the sites to be compared:-
Estadao has a short article about the issues in Buriticupu in Portuguese. It includes this image:-
These issues at Buriticupu are primarily rapid headward and lateral erosion of gullies, driven by toe erosion and then slope failure, as the image above shows. The materials appear to be deeply weathered (hence the red colour), and thus will be weak. The Estadao article ascribes the problems to ‘deforestation, disorderly occupation, relief and sandy soil’.
In my experience, these problems are often associated with inadequate water management in the towns, both in terms of water supply and sewage disposal, and the control of surface drainage from the roads and pavements. It would be interesting to know if that is the case here. Unfortunately, once these problems start they are difficult to stop unless there is substantial engineering intervention into the gullies themselves, along with good water management in the town.