Assessing Climate Change and Variability Impacts on Water Resources and Smallholder Agriculture in the Offin Sub-Basin of Ghana

Abstract

Climate change and variability is becoming an issue of global and regional concern as its impacts are increasingly taking hold of diverse sectors of the world. Temperatures increasing and rainfall becoming highly variable have had major impacts globally, with Africa faced with the harshest conditions. Although the continent’s contribution to global warming and subsequently climate change is the lowest, Africa’s low adaptive capacity tend to put the continent at the forefront of the battle with climate change and variability. Several studies have stated explicitly that climate change tends to increase the demand on the limited useful freshwater resources in the continent, even as the populations are increasing and the water demand for agriculture, industry and domestic purposes keep increasing. The over-dependence of Ghana and other African countries on climatesensitive sectors such as water and agriculture has greatly contributed to the high vulnerability of the continent. Water resources and agriculture inevitably do contribute largely to socio-economic development in Ghana. These sectors are however exposed to first-hand harshness from climate change and variability, nullifying gains made by the country to attain sustainable development. This study was geared towards assessing climate change and variability impact on water resources and smallholder agriculture in the Offin sub-Basin of Ghana, which is of high socio-economic value. In order to detect possible changes in the climate of the basin, a 46-year daily rainfall and temperature data was analysed. It was revealed that temperatures had been on the rise, whereas rainfall had been diminishing over the years. Analysis of a daily 40-year streamflow data also revealed a decreasing trend. In order to determine the strength of the influence of rainfall and temperature on streamflow in the basin, the Pearson Correlation Coefficient was used. To assess the impacts climate change and variability have had on smallholder agriculture in the basin, a semistructured questionnaire was administered. It was observed that farmers and indigenes do have a general knowledge of climate change and the challenges it poses on their farming activities. Various means by which these farmers had been coping with the impacts of climate change and variability were also assessed, even as a means of contributing to building resilience in these climate sensitive sectors. Developing and enhancing these adaptive measures in crop-production dominant rural areas, would foster resilience to climate change and variability in the agriculture sector of the country, reduce rural poverty as well as boost economic growth in Ghana and Africa at large