Impacts of Climate Change and Human Activities on Fire Hazards in Kakamega Forest, Kenya

Abstract

Kakamega tropical forest is found in western Kenya. It lies about 20km on the East of Kakamega town and about 50km from the Lake Victoria. It borders the Nandi Escarpment to the East. Kakamega forest serve as habitat for tense biodiversity, water towers and as key natural carbon sinks. There was clear rise in forest-fires, both in numbers and intensity among major tropical forests across the globe. The study sought to unravel the complex interaction of natural variables, including climate change, and human activities that can prime fire hazards in a forest ecosystem. The wind regime characteristics within and around Kakamega Forest were examined. Daily wind data from Kenya Meteorological Department (KMD) data were used to generate a sample daily-wind-rose diagram in the study. Monthly wind data was used to generate the climatic wind-rose diagram. Climate Hazards Group Infrared Precision with Station data (CHIRPS), a 35+ year quasi-global data, was used to compute precipitation and temperature trends. The field visits, questionnaires, interview with key informants and desktop reviews captured relevant data on social-demography of respondents, fire events in study area and related causes, including current legal institutions and relevant policy-documents related to forest fires and climate change understanding were assessed. The study established from CHIRPS data that rainfall in the study area was on a slight declining trend of between 300 to 400mm per decade. The results from CHIRPS areal-average (spatial) data indicate that maximum (Tmax) and minimum (Tmin) temperatures were on the upward trend. The Mann Kendall test on Tmax and Tmin data from Kakamega Meteorological station generated a p-value of 0.000002 and p-value of 0.000001, respectively. P-value for Tmax and Tmin was less alpha (0.05), hence Kakamega station data was useful for trend analysis. The wind-rose diagram analysis revealed that the wind around Kakamega forest was of easterly regime with average speed of between 0-20 knots. Wind speed, at 10 metres above the ground, must exceed 3 knot ms-1 to support the spread of the wildfire. Main causes of fire around and within Kakamega forest were intentional and the most susceptible tree species to fire were the plantation comprising exotic species like Blue-gums (Eucalyptus-saligna), Pines (Pinus patula) and Cyprus (Cupressus Lusitania). The study recommended for more studies into interplay of climate elements, vegetation types and ignitions influenced by human activities in Kakamega forest. The study also cautioned that one intense fire event could inflict irreversible impact on the only remaining remnant of tropical forest in Kenya.