Fire Risk Assessment in the Roburnia Commercial Forestry Plantation, Mpumalanga Province, South Africa

Abstract

The aim of this study was to undertake fire risk assessment at Roburnia Plantation in order to determine factors that contribute to fire risk, risk level, and extent of fire damage. The study was conducted at the Roburnia Plantation, Mpumalanga south region, South Africa. Both epistemological and scientific research designs were used in this study in order to assess the level of fire risk at Roburnia Plantation. The quantitative approach was used to collect data on the factors that influence the occurrence of fire risk, while the qualitative approach was used to collect data on perceptions on fire risk level and prevention measures. A questionnaire was used to collect the primary data, while the secondary data was collected from online databases and through literature reviews. Climatic and fire danger index (FDI) data sets were gathered from the study area, which was downloaded from the Vital Weather System. Data on the number of hectares burnt, number of fires and fire extinguishing costs were downloaded from the Disaster Management System (DMS) at the Roburnia Plantation. Purposive sampling method was followed in order to collect data and information from experienced sampled people. Data on fire risk assessment and perceptions on fire prevention measures were collected through interviewing foresters (5) and fire fighters (3) managers at Roburnia Plantation. Officials dealing with commercial forest management were also interviewed at the Department of Agriculture, Fisheries and Forestry (7), Working on Fire in Mpumalanga and Limpopo (1), and NCT Forestry Cooperation Limited (2). A transect line (1km) was also followed in order to collect fuelload data per square meter, measured in every 100m along the transect line. The amount of fuelload was measured using an electronic kitchen measuring scale. The collected data sets were captured in the Ms Excel 2007 and then analysed using descriptive and inferential statistics. Regression analysis, analysis of variance (anova: single factor) and t-test were applied. The LvFDI model and risk equations were also employed in order to analyse the extent of fire risk at Roburnia Plantation. Results of this study show that rainfall and relative humidity have overriding influence on the rate of FDI. This is due to the fact that high moisture content in the fuel has the potential to stop fire, whilst low moisture content in the fuel influence efficient burning. The FDI values are low during summer, mainly due to high amount of moisture on the fuel, but becomes high during winter, mainly due to low moisture content in the fuel. This study found a positive regression between the availability of rainfall and the rate of FDI at Roburnia Plantation (R2 = 0.1). The average daily FDI was high when the average daily amount of rainfall was at 0mm, but decreases when the amount of rainfall increases above that level. There was also a positive regression between the availability of humidity and the rate of FDI at Roburnia Plantation (R2 = 0.7). The FDI was high (above 45) when the relative humidity was low (less than 30%), but decreases when the relative humidity increases from more than 30%. Analysis of this study found a weak regression between temperature and the rate of FDI at Roburnia Plantation (R2 = 0.000). This suggests that increase in temperature has insignificant effect on the rate of FDI. This is due to the fact that very dangerous FDI values were predicted even when the temperature was less than 1 degree Celsius. This study also found a weak regression between the velocity of wind and rate of FDI at Roburnia Plantation (R2 = 0.005). This is due to the fact that very dangerous FDI values were predicted even when the wind velocity was low, at 0 km/h. The application of Wisner and UNISDR risk equations shows that the Roburnia Plantation is highly exposed to fire risks, followed by harsh weather condition and least by tree diseases, pests and pathogens. This study also found that more than 70% of fires at Roburnia Plantation are caused by arsons. Species that are mostly affected by fires are the Gums and Pines. The mean (± s.d.) number of fires, hectares burnt and costs for extinguishing fires at Roburnia Plantation between 2007 and 2011 were 165.40 ± 56.19, 126.45 ± 110.81 and R471,903.01 ± R256,330.32 respectively. The findings of this study therefore implies that management at Roburnia Plantation need to effectively implement fire prevention plans in order to reduce the number of fires, hectares burnt and costs incurred due to extinguishing fires.