Impact of climate change on Vea Catchment and irrigation scheme in Upper East Region of Ghana

Thursday, 17 December 2015
Poster Hall (Moscone South)
Andrew Manoba Limantol, West Africa Science Service Centre on Climate Change and Adaptation Land Use, Graduate Research Program, Climate Change and Water Resources/Faculty of Science and Techniques, University of Abomey-Calavi, Cotonou, Benin, Abel Afouda, West African Science Service Center on Climate Change and Adapted Land Use (WASCAL); Graduate Research Program of, Cotonou, Benin, Bernd Lenartz, University of Rostock, Agricultural and Environmental Sciences, Rostock, Germany and Wilson Agyei Agyare, Kwame Nkrumah University of Science and Technology, Department of Agricultural Engineering, Kumasi, Ghana
The study assessed the future impact of climate change (CC) on water resources availability in the Vea catchment of the Upper East of Ghana for irrigated agriculture. A questionnaire survey targeting farmers with at least 30 years of farming experience in the area was conducted in 6 of the 11 agricultural extension areas (EAs) in the catchment (305 km2). Data on perception about CC, adaptation measures and barriers were captured by the questionnaire. Focus group discussions were also conducted in each of the 6 selected EAs. Additionally, 8 stakeholder institutions were interviewed. Climatic data over a period of 1972 to 2012 from four stations were evaluated. Future climate simulations from 16 Regional Climate Models were used to predict future streamflow with IHACRES runoff model. The WEAP model was used to assess future water availability in two future time slices, 2021-2050 and 2071-2100. About 89.5% of 466 questioned farmers believe that temperature increased over the past 30 years, while over 94% of farmers believe that amount of rainfall; duration, intensity and rainy days decreased. Over 96% of farmers believe that their farms are extremely vulnerable to decreased rainfall, droughts and changed timing of rainfall. While analysis of climatic data shows rising trend in temperature, no long-term trend and no variability changes in both annual and monthly rainfall amounts were evident. High evapotranspiration due to rising temperature may have triggered the farmers’ perception about rainfall trend and droughts in the area. Several measures such as cropping of new varieties, changing farm locations and use of more fertilizer have been employed by farmers to adjust to CC. It was found that CC could cause severe shortfall in water availability for irrigation and domestic supply in the coming decades. Government needs to assist farmers with alternative irrigation schemes and drought resistant crops in order to sustain livelihoods of farmers on the long run.