Climate Change Vulnerability Indices for Kakamega - Nandi Forest Complex in Kenya

Abstract

Climate change has been defined as ‘a change in the average conditions — such as temperature and rainfall — in a region over a long period of time’. Vulnerability can be defined as the extent to which a socio-economic and environmental system is exposed to climate change. Determination of vulnerability can enable mitigation measures to be taken against climate change induced effects. In particular, the use of Climate Change Vulnerability Indices (CCVI) ensures that correct and timely actions to mitigate impacts can be taken. In a study to evaluate climate change vulnerability (CCV) in the Kakamega-Nandi forest complex, annual rainfall and temperatures, vegetation cover, land use and soil organic carbon were measured and used to construct Climate Change Vulnerability Index (CCVI). CCV was formulated as a function of soil organic carbon (SOC), vegetation cover (LAC), land-use/land-use change (LUC), temperature changes (TEMPs) and rainfall amount (RAIN). Thus: Initial analyses revealed that some variables were significantly co-related to others and these were removed to avoid auto-correlation. Climate change well being indices were developed using a weighting factor (Wt_i) for vegetation cover and land use / land cover (LULAC), with Natural forests given the highest weight (well-being) and bare land the lowest. The weighting factor was guided by ANOVA results of SOC and separation of means which gave groups that significantly differed statistically at α=0.05. The final CCVI was calculated as: The results showed that land use and land cover substantially influenced climate change vulnerability with bare land showing the highest vulnerability index and intact Natural forests and plantations showing the lowest CCVI. Effects of rainfall and temperatures, variables which have been associated with climate change most often, were correlated with land use and land cover in this study. The developed index can serve as a useful tool to assist in decision-making regarding the vulnerability of communities in areas with extreme land-use land cover changes. We recommend that further in-depth studies be carried out to improve the sensitivity of the CCVI developed in this study.