An in-depth study of bush fires in Namibia by Simon Trigg from the Namibia and Natural Resources Institute in Oshakati and Johan le Roux from the Etosha Ecological Institute at Okaukuejo indicate that the phenomenon has a limited number of causes that could easily be traced.
The researchers divided the country into zones and from there established that different zones are prone to certain kinds of bush fires and that humans are in most cases the cause of such fires.
According to the study, fires in Zone 3 (see attached map) are generally not desired as the resulting loss of fodder may constrain pastoralism. Therefore, in cases where fires occur, coordinated efforts are made to put them out quickly. This means fires rarely spread over very large areas. However, decades of fire exclusion have contributed to severe bush encroachment over extensive areas.
In Zone 6, people light the majority of fires for many reasons. Those reasons include: to stimulate the growth of fresh grass for cattle, to attract game, to flush out game animals that can then be hunted, to clear vegetation around waterholes and honey-gathering areas, to clear land for cultivation, or to promote the regeneration of grasses used for thatching. Arson also occurs. As most fires occur at times with no convective thunderstorm activity, it is clear that lightning plays a relatively minor role (Mendelsohn and Roberts 1997).
In Zones 3 and 5, fires originate either as a result of lightning strikes during convective storms at the beginning of or end of the burning season, or are started accidentally during charcoal making or from inadequately supervised campfires, or careless use of cigarettes.
In Zone 5, large areas are sometimes burned accidentally as the uncontrolled extension of fires deliberately lit to clear new fields.
In Zone 4, fires are ignited mainly by lightning and park management and occasionally by accident.
In Zones 1 and 2, the rare fires that occur are started mainly by accidental ignition and lightning.