Eric Mensah Mortey

The uncertainties and biases associated with Global Climate Models (GCMs) ascend from global to regional and local scales which delimits the applicability and suitability of GCMs in site-specific impact assessment research. The study downscaled two GCMs to evaluate effects of climate change (CC) in the Black Volta Basin (BVB) using Statistical DownScaling Model (SDSM) and 40-year ground station data. The study employed Taylor diagrams, dimensionless, dimensioned, and goodness of fit statistics to evaluate model performance. SDSM produced good performance in downscaling daily precipitation, maximum and minimum temperature in the basin. Future projections of precipitation by HadCM3 and CanESM2 indicated decreasing trend as revealed by the delta statistics and ITA plots. Both models projected near- to far-future increases in temperature and decreases in precipitation by 2.05-23.89, 5.41–46.35, and 5.84–35.33% in the near, mid, and far future respectively. Therefore, BVB is expected to become hotter and drier by 2100. As such, climate actions to combat detrimental effects on the BVB must be revamped since the basin hosts one of the largest hydropower dams in Ghana. The study is expected to support the integration of CC mitigation into local, national, and international policies, and support knowledge and capacity building to meet CC challenges.

Climate change (CC) is the new normal in the 21st century. Effects of CC have intensified in Ghana, especially in the Greater Accra region over the last two decades. CC assessment under the new IPCC scenarios and consistent local station data is limited. Consequently, CC assessment is becoming difficult in data-scarce regions in Ghana. This study utilizes six different Regional Climate Models under the 6th IPCC Report’s Shared Socioeconomic Pathway scenarios (SSPs) of the CMIP6, which were bias-corrected with CMhyd over Accra using ground station and PUGMF reanalysis data. The study reveals a reduction and potential shift in the intensity of precipitation in the region under the SSPs. Maximum temperature is expected to increase by 0.81-1.45°C, 0.84-1.54°C, 0.96-1.70°C and 0.98-1.73°C, while minimum temperature would likely increase by 1.33-2.02°C, 1.49-2.22°C, 1.71-4.75°C and 1.75-4.83°C under SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5 scenarios, respectively. Thus, temperature will likely increase, especially at night in the near future. Rising temperatures and changes in precipitation have impacts on all strata of society, from agricultural production to power generation and beyond. These findings can help inform Ghanaian policymaking on Sustainable Development Goal 13 and nationally determined contributions within the Paris Agreement.

Management of hydroelectric dams is an aspect of sustainability that comes with resolving problems locally. The use of global indicators has not been a sustainable solution, thus the need for local indicators. Besides, current sustainability assessment tools lack the integration of climate, making assessments in a climate change context impossible. In this paper, we present management and sustainability assessment in a climate change context using sustainability indicators. We modeled a change in the climate using normal, moderate, and extreme climate conditions defined by Standardized Precipitation Indices (SPI) values. Out of 36 years analyzed, 24 years fall in the near-normal climate regime, and the remaining 12 years in moderate and extreme conditions, making near-normal climate regime the basis for managing the Taabo Dam. The impact of climate, techno-economic, and socio-environmental indicators on sustainability were investigated, and the results were analyzed according to scenarios. Climate adaptation shows higher sustainability indices than techno-economic and socio-environmental scenarios. Probability matrices show high and low values, respectively, for environmental and flooding indicators. Risk matrices, on the other hand, show that even with small probability values, risks still exist, and such small probabilities should not be taken as an absence of risk. The study reveals that sustainability can be improved by integrating climate into existing assessment methods.

Sustainable hydroelectric projects are judged by their contribution to sustainable development, long-term viability, and ability to integrate sustainability goals. This paper analyses the Bui hydroelectric dam in Ghana vis-à-vis these expectations using sustainability indices. A multi-criteria analysis tool, APIS (Aggregated Preference Indices System), is used to build indices for Bui dam for four hydrologic seasons. An analysis of the indicators used revealed that environmental indicators are weightiest and economic indicators have the least weight. Comparative analysis of the Bui dam project shows 40%, 36%, 18%, and 6% priority for technical, economic, social, and environmental criteria, respectively, during its implementation stages. Per estimation of this work, the general sustainability index of the Bui dam is between 0.4 and 0.6 on a scale of 0 to 1. The impact of seasonal climate change will reduce the index to below 0.5 for three hydrologic seasons. The results show that Bui dam has an average but weak index of sustainability. Multi-criteria analysis offers quality assessment of energy projects, which is valuable for analyzing proposed or existing energy projects. This paper shows the possibility of using multi-criteria analysis approach to assess the sustainability of a hydroelectric dam. The approach offers a quantitative and qualitative assessment of a hydroelectric dam via a suitable choice of indicators.