While the technique is very simple, it also has problems: Often, fires created get out of control, and more land is burned than necessary. That way, a territory the size of Belgium burned down in a fire, created in 1989, in the state of Roraima in Brazil. In general, there are few large fires in the rainforest. the climate is very wet, and rivers block the fires. In southeast Asia, between May and October, many people have health problems because of the clouds of smoke. During that time, slash-and-burn operations happen in Indonesia. These fires are responsible for the clouds. 