Lavaka: it is these huge gaping wounds that can be seen when we follow the RN1. They are the result of heavy rains that cause significant digging: a crevasse can form in only two hours if conditions are met.
For example, on the domes of ancient volcanoes in the Itasy region, peasants cultivate cassava on the flanks, weakening the plant layer that could protect the earth and its humus. After only 2 or 3 seasons, the rain grazes the earth and carries the surface layer to the bottom of Lake Itasy, asphyxiating the fauna and flora.
