Classification of veldfire risk in South Africa for the administration of the legislation regarding fire management

Abstract

The risk associated with vegetation fires (veldfires) in South Africa is substantial, and veldfires cause severe losses to life, property and the environment in most areas of the country. However, this risk has two parts: first, that arising from wildfires (i.e. unwanted veldfires) that cause damage to assets, and, second, the risk arising from ecologically inappropriate fire regimes in environments where fire plays an ecological role. South Africa has adopted the National Veld and Forest Fire Act, No. 101 of 1998 as a major instrument for improved management of veldfires. This paper provides a classification of veldfire risk in South Africa, based in the first instance on ecological information, as a contribution to a strategy for the implementation of the new legislation. We assigned each of the major vegetation types in South Africa to one of 13 different fire-ecology types. A fire-ecology type comprises one or more vegetation types which have a similar frequency and nature of veldfires. South Africa is divided into six metropolitan and 231 local municipalities and each of these was assigned a fire-ecology type. Wildfire risk was assessed as the combination of the likelihood and consequences of veldfires in each fire-ecology type. The likelihood of veldfire was related to the average fire return period for that vegetation type, determined from the literature. Likelihood ratings were almost certain (fires 1 in 2 years), likely (fires 1 in 5 years), possible (fires 1 in 10 years), unlikely (fires 1 in 20 years) and rare (fires 1 in 100 years). The consequences of veldfires in each fire-ecology type were estimated from a range of sources including fire reports and newspaper accounts of veldfires. The consequences of veldfires were grouped into the following categories: catastrophic (regular loss of life and significant economic consequences); major (extensive injuries and serious economic consequences); moderate (localised damage and economic losses); minor (minor financial losses and damage); and insignificant (damage inconsequential). Risk categories were defined as low, medium, high or extreme, depending on the combinations of likelihood and consequences. For example, if veldfires almost certain and catastrophic, risk was extreme; and if they were rare, but had moderate consequences, the risk was low. Grassland and savanna areas, which cover almost 40 per cent of the eastern half of the country, were at highest risk. Mediterranean shrublands, which are well known for their veldfires were rated only as high, because most of the area is mountainous, infertile, and unoccupied, or sparsely occupied.