Emerging from research in natural hazards, the concept of vulnerability to environmental risks which entered development debates in the 1990s, have been applied widely in climate related issues with different disciplines and policy communities (Wisner et al. 2004). Vulnerability is defined as a “measure of a person or group’s exposure to the effects of a natural hazard, including the degree to which they can recover from the impact of that event” (Blaikie et al. 1994). This view focuses on factors such as the frequency, intensity and nature of the physical hazard as key components of vulnerability and the exposure of communities to such hazards, paying less ...view middle of the document...
Exposure refers to the degree to which a particular unit or system is put under climatic stress (Gbetibouo et al. 2010). It may be in a form of long-term changes in climatic conditions or changes in climatic variability, including the magnitude and frequency of extreme events. Sensitivity refers to the degree to which a system is modified or affected by internal or external disturbances (Gallopin 2006). Adaptive capacity refers to the potential to adapt and reduce a system’s vulnerability (Luers 2005). The capacity to adapt to climate variability will vary significantly in accordance with level of development and resource capacity.
The northern part of Ghana (approximately 97000km2) comprises the Upper East (UER), Upper West (UWR) and Northern region (NR) (Figure 1). These are considered as three most deprived regions among the ten regions of Ghana (Ghana Statistical Service (GSS) 2010). Northern Ghana falls within the Guinea and Sudan Savannah agro-ecological zones and the majority of the households in the regions reside in rural areas, are engaged in rainfed agricultural and land-based economic activities. Millet and Sorghum are two main principal crops, only cultivated under rainfed in this part of the country. Other rainfed crops include maize, rice and peanuts. Seasonal rainfall distribution is monomodal with averages ranging from 900-1100mm. The rainfall season starts in April and ends in October reaching its peak in August, followed by a long dry season from October to April. Temperatures are high throughout the year with an average of 28oC.
Figure 1: Map of Ghana (a) showing the northern Ghana (b) with vegetation type (Source: Dosu 2011)
Data Collection and Analysis
Climatic data including rainfall, maximum temperature and minimum temperature parameters for the three regions covering a period from 1961–2010 were collected from the Ghana Meteorological Agency. Monthly millet and sorghum production data from 1991-2010 were collected from the Statistics, Research and Information Directorate of Ministry of Food and Agriculture (MOFA 2011) and aggregated into yearly production. For socioeconomic data used for vulnerability analyses, 350 farmers from the economically active population in each region were randomly selected and interviewed using a semi-structured questionnaire. Data obtained from these interviews were then corroborated with data from 2010 national census (GSS, 2010).
Climate Trend Analysis
The averages of annual rainfall, maximum temperature and minimum temperature (1961–2010) for each region were computed and analysed using Excel. Descriptive statistics were run to determine number of occurrence of a variable, means and extent of variations. The variability of monthly rainfall was expressed with the coefficient of variation (CV) using mean annual rainfall data. A high CV indicated that the high spatial variability. These analyses aimed to provide a deeper understanding of...