Predicting hydrological response to climate change in the White Volta Catchment, West Africa

This study uses an ensemble of Regional Climate Model (REMO), to simulate and project the climate at local scale in order to investigate the hydrological impact of possible future climate change in White Volta Catchment (West Africa). The results, obtained from the REMO climate model, were compared to the observational datasets for precipitation and temperature for the period 1995-2008. The projected meteorological variables for the period 2030-2043 were used as input to the Soil and Water Assessment Tool (SWAT) hydrological model which was calibrated (R2 = 0.88 and NSE= 0.84) and validated (R2 = 0.82 and NSE= 0.79) with historical data to investigate the possible impact of climate change in the catchment. The results obtained from the investigation revealed that catchment is sensitive to climate change. With a small increase of 8% and 1.7% of the mean annual precipitation and temperature respectively, annual surface runoff, annual baseflow and evapotranspiration recorded increment of 26%, 24% and 6% respectively

Usability research laboratory for geospatial and allied applications

The use of computers has penetrated every sector of the Ghanaian economy. Researchers in Ghana and the KNUST environs are continually developing computer applications for users for addressing societal problems, as well as, automating the manual process of doing things. Researchers and developers are moving away from the use of commercial software to customized and user-friendly applications to suit the Ghanaian economy, thereby maximizing profit. End user applications are developed daily and these applications are most often not subjected to usability testing and evaluation with real users. Usability engages individuals as testing participants of the target audience to assess the degree to which a computer application meets specific usability standards. This research, funded by Building Stronger Universities II (BSU II) Project, uses the ‘Think Aloud’ technique in developing a usability laboratory for testing end user applications before being released to the final user. End user applications such as problem-based learning applications for distance learning, computer supported collaborative learning applications, drought and flood early warning applications, land use land cover related applications, climate change related applications, etc. will benefit from this usability testing laboratory.  The findings from this project contributes to the understanding and exploration of alternatives of end user applications. &nbsp

Increased seasonal rainfall in the twenty-first century over Ghana and its potential implications for agriculture productivity

The slightest change in rainfall could have a significant impact on rain-fed agriculture in countries like Ghana. This study evaluated for the first time the performance of the statistical downscaling model (SDSM-DC) at 2m spatial resolution in simulating rainfall in Ghana for the base period 1981–2010. It further analysed the projected changes in seasonal rainfall pattern across different agro-ecological zones for the twenty-first century under RCP 4.5 and 8.5 emission scenarios over Ghana. Ensemble mean of simulated rainfall data (2011–2099) generated by 43 GCMs in the Coupled Model Intercomparison Project Phase 5 (CMIP5) were used as base factors for local future climate scenarios generation. Performance analysis of SDSM-DC shows a Nash–Sutcliffe efficiency, percent bias and RMSE observations standard deviation ratio of 0.88, −19 and 0.34, respectively. Generally, seasonal rainfall amount is expected to increase between 10 and 40% in all the agro-ecological zones in Ghana by the end of the twenty-first century. Off-season rainfall in December–February shows more than 100% increase in the Guinea Savannah zone. Rainfall projected under RCP 4.5 was on average 2% higher than RCP 8.5 in all the seasons throughout the century. Based on these results, it is appropriate to suggest a high incidence of flooding across Ghana in the twenty-first century. This could have dire consequences on agriculture which contribute to a large proportion of Ghana’s GDP. Therefore, for sustainable food production and security in the twenty-first century, Ghana needs climate adaptation policies and programmes that encourage the design and implementation of early warning systems of meteorological hazards and the introduction of new crop varieties that are flood tolerant.</p

Assessment of vegetation dynamics in Upper East Region of Ghana based on wavelet multi-resolution analysis

Vegetation variation offers significant information for environmental planning, management, sustainability and prompts caution of ecosystem degradation, particularly for the semiarid regions. Normalized difference vegetation index (NDVI) discloses the coverage growth situation, biomass and photosynthesis strength of vegetation and land-cover alterations. Wavelet was used to decompose NDVI time series into subseries at various timescales. This study used a multi-resolution analysis in association with Mann–Kendall and Sen’s Slope at 95% confidence interval to determine the trends in vegetation dynamics at the Upper East Region (UER) of Ghana. GIMMS NDVI3g time series was used to evaluate the performance of the vegetation at seasonal, interannual and intraannual timescale from 1982 to 2015. The results showed that the variability in NDVI in the region is annually significant. At the seasonal level, the whole surface area showed negative vegetation trend. In terms of the intraannual changes, 11.76% of the surface area showed critical patterns. At the interannual scale, results revealed that 4.40% of the surface area demonstrated significant patterns, while 95.60% indicated nonsignificant pattern. Overall, there was negative performance in the vegetation growth from 1982 to 2015. The 16.6% decrease in vegetation dynamics can be attributed to anthropogenic activities. The results from this study would benefit and provide helpful assistance to water resources managers, agricultural and ecological development officers for sustainable planning of UER

Spatiotemporal dynamics of rainfall in Upper East Region of Ghana, West Africa, 1981-2016

There has been an increasing concern about effects of global warming on rainfall. Negative impacts on rainfall affect the environment and socio-economic activities of nations, globally. Rainfall characteristics at the Upper East Region (UER) of Ghana in terms of temporal and spatial variability are investigated from 1981 to 2016 using rainfall data from Ghana Meteorological Agency (GMet) and Climate Hazards Group Infrared Precipitation with Station. Using cumulative residual analysis, Mann–Kendall (MK), Sen’s slope, wavelet transform (WT) and principal component analysis (PCA) tests, the rainfall variability in UER was examined. Results showed that 1981, 1999, 2002 and 2013 were years of major changes in rainfall variation. The MK and Sen’s slope showed that 55.71% of UER have decreasing monthly rainfall with 27.34% significant trend. Months April, May and June showed decreasing rainfall trends. Months July, August and September showed significant increasing rainfall trend. WT revealed a significant variation in the annual rainfall. PCA revealed that the spatial variability of rainfall in UER is very diverse with 33.76% of the variability located in the northeastern part. The findings serve as benchmark in providing in-depth understanding of rainfall variation in UER for water resource managers, agriculturalists and drought mitigation

Terrestrial water storage and climate variability study of the Volta River Basin, West Africa

The Volta Basin in West Africa plays a crucial role in supporting the livelihoods of millions of people, and effective management of its water resources is essential for climate change adaptation. This study utilized remote sensing technology, specifically the Gravity Recovery and Climate Experiment (GRACE), to assess terrestrial water storage (TWS) and its response to climate variability within the Volta Basin. The methodology involved integrating GRACE data with ground-based measurements, climate models, and other satellite observations to enhance the accuracy of TWS assessment. Despite numerous studies conducted within the basin, this research employed additional statistical techniques such as Independent Component Analysis (ICA) and El Niño Southern Oscillation (ENSO). It also utilized Climate Hazard Group Infrared Precipitation with Station (CHIRPS) to determine variations in TWS and climate variability observed within the Volta Basin. The results provide valuable insights into TWS dynamics, highlighting the complex interplay between precipitation patterns, groundwater storage, and surface water availability. Also, it was revealed that rainfall signals were strongest in the northernmost part of the basin, reaching a maximum value of 10 mm, while the lowest value of 5.5 mm was recorded in the southern part of the basin. Similarly, TWS signals were highest in the northern and lowest in the southern part of the basin, exhibiting values related to that of rainfall. Additionally, the highest TWS value of 250 mm was identified between 2010 and 2012. The increase in TWS during this period correlates with the occurrence of La Niña that happened between 2010 and 2012. This study offers essential information for water resource management, drought monitoring, flood forecasting, and climate change adaptation strategies not only within the Volta Basin but also in other basins across the globe