Sustainability of Raw Water Supply in Nawuni River for Tamale Metropolis and Environs, Ghana

Water supply service is possibly the most essential of all public service in Ghana and any obstruction to its delivery threatens human survival. A major challenge to water supply is the rapid urbanisation, which has increased water demand in the urban areas, placing pressure on service providers to meet demand. Perennial water shortages in Tamale, is linked to several factors including the inability of the service provider to keep pace with the demand of the rapidly increasing population of the city. This situation could be exacerbated by natural climate variation and competing water uses upstream the city supply source. This study investigates the sustainability of raw water supply to Tamale metropolis and environs using Water Evaluation and Planning Model (WEAP). The investigation was based on scenarios analysis: Reference scenario, Population and Socio-economic growth, intensifying upstream water use and Extended Dry Climate. The results revealed that, intensifying upstream water use as projected in the study do not have impact on the downstream water availability for sustainable water supply. However, the assessment based on High Population and Socio-economic growth results showed significant value (229 million cubic meter) of Unmet Demand in year 2035 for Urban and rural demand site. The results also showed that, the water demand will outstrip raw water supply by 2029 when Extended Dry Climate occurred under scenario High population and Socio-economic growth. Possible options of water storage reservoir should be investigated so as to mitigate the effect of extended dry season. Keywords: Downstream water, Reliability, Supply requirement, Supply delivered, Un-met demand. DOI: 10.7176/JEES/13-6-05 Publication date:August 31st 202

Small Scale Irrigation Development in Upper West Region, Ghana; Challenges, Potentials and Solutions

Agriculture production is largely rain fed in Ghana and West Africa. Meanwhile the rainfall pattern in these arid and semi-arid areas is short and erratic. In the Upper West Region, rainfall starts in May and ends in October. Small-scale irrigation systems have been introduced to ensure food security in the region. Food insecurity and poverty are the major setbacks resulting in migration out of the region in search of other menial jobs during the dry season. The study was carried out in four districts, Wa West, Nadowli, Lambussie-Karni and Nandom with their respective schemes at Siru, Sankana, Karni and Kokoligu. The scope of the study was to assess the state of irrigation structures, identify challenges and potentials and propose ways to improve irrigation development in the region. It was ascertained that irrigation structures in the region are in a very deplorable state leading to inadequate water supply to farms. Although soil nutrient levels in the study area are low, the high clay contents compared to most soils from the region suggest a higher ability to hold available plant nutrients for plant growth. The study also found out that irrigation in the region lacked access to inputs and credit, ready markets, mechanized labor and extension services thus resulting in the poor performance of small-scale irrigation schemes. The study also identifies water and land as major potentials for production if reliable farmer support and the appropriate technologies are available. There is the need for major stakeholders such as farmers, government (MMDAs), policy makers, research institutions and non-governmental organizations to complement efforts to rehabilitate irrigation structures, facilitate input availability, easy access to credit and enhance extension services to boost the development of already existing schemes in the region. Keywords: small scale irrigation, development, challenges, potentials, solution

Evaluation of incorporating plastic wastes into asphalt materials for road construction in Ghana

In improving the aesthetics of the environment, the management of plastic wastes cannot be left out of the picture. Among the numerous ways that plastic wastes are managed, incorporating them into plastic roads is another viable option. This study quantified plastic wastes generation in Sunyani Municipality in Ghana and investigated the optimum percentage of asphaltic materials that could be made of plastic wastes for road construction in Ghana. Plastic Wastes were obtained from social gatherings, residential areas and restaurants, there was dialogue with key persons in the plastic industry and various experiments were also conducted for plastic wastes utilization in road construction. It was found that only one entrepreneur recycles the plastic wastes to make bags, dustbins, ropes and many more in the Municipality. It was also estimated that plastic wastes generation in the municipality per capita was 49.7 g/person/day whiles the total plastic wastes generated in the Municipality was 6,725.64 kg/day. In addition, numerous experimentations proved that it is possible to substitute about 10% of asphaltic road materials with plastic wastes as plastic coated aggregates (PCA) to meet the Ghana Highways Authority (GHA) standards for road construction. The novelty finding in this research is that substitution of about 10% or more of asphaltic road materials in Ghana with plastic wastes could bring economy and cost savings in both road construction and plastic wastes management in Ghana

Assessment of Spatio-Temporal Changes of Land Use and Land Cover over South-Western African Basins and Their Relations with Variations of Discharges

West African basins play a vital role in the socio-economic development of the region. They are mostly trans-boundary and sources of different land use practices. This work attempts to assess the spatio-temporal land use and land cover changes over three South Western African basins (Volta, Mono and Sassandra basins) and their influence on discharge. The land use and land cover maps of each basin were developed for 1988, 2002 and 2016. The results show that all the studied basins present an increase in water bodies, built-up, agricultural land and a decline in vegetative areas. These increases in water bodies and land use are as a result of an increase in small reservoirs, of dugouts and of dam constructions. However, the decline in some vegetative clusters could be attributed to the demographic and socio-economic growth as expressed by the expansion of agriculture and urbanization. The basic statistical analysis of precipitation and discharge data reveals that the mean annual discharge varies much more than the total annual precipitation at the three basins. For instance, in the entire Volta basin, the annual precipitation coefficient of variation (CV) is 10% while the annual discharge CV of Nawuni, Saboba and Bui are 43.6%, 36.51% and 47.43%, respectively. In Mono basin, the annual precipitation CV is 11.5% while the Nangbeto and Athieme annual discharge CV are 37.15% and 46.60%, respectively. The annual precipitation CV in Sassandra basin is 7.64% while the annual discharge CV of Soubre and Dakpadou are 29.41% and 37%, respectively. The discharge varies at least three times much more than the precipitation in the studied basins. The same conclusion was found for all months except the driest months (December and January). We showed that this great variation in discharge is mainly due to land use and land cover changes. Beside the hydrological modification of the land use and land cover changes, the climate of the region as well as the water quality and availability and the hydropower generation may be impacted by these changes in land surfaces conditions. Therefore, these impacts should be further assessed to implement appropriate climate services and measures for a sustainable land use and water management

Characterisation of visual defects on installed solar photovoltaic (PV) modules in different climatic zones in Ghana

Visual defects on photovoltaic (PV) modules depend on climatic conditions and hence, vary from one country to another. This study characterised visual defects on PV modules installed in three climatic zones in Ghana and determined the link between the defective modules and output power degradation. It identified and classified these defects according to climatic zones and age groups of the modules. It also compared the degradation rates of the modules with visual defects and those without visual defects to determine the influence of the visual defects on output power degradation of the modules. The study used 104 PV modules of different technologies, which were older than 5 years, selected from 16 PV systems installed in the three climatic zones. A walkthrough visual inspection of the modules was performed to observe the visible defects, followed by current-voltage (I-V) curve tracing. The results revealed that encapsulant discoloration and corrosion of frames were found on 50% and 30% of the modules respectively. The other identified visual defects include encapsulant delamination, corrosion of metallisation, sealant infiltration, snail track and cracks in cells, which were few. Encapsulant discoloration was predominant in all the climatic zones and highest in Interior Savannah Climatic Zone while corrosion of frame was prevalent in Dry Equatorial Climatic Zone. The recently installed PV modules succumbed more to these defects than those installed years ago. Overall, modules with visual defects degraded at faster rates than those without visual defects, but the output power degradation could not be wholly attributed to these visual defects because some of the modules with severe visual defects degraded lesser than some of the modules with minor or no visual defects and vice versa. However, the visual defects provided initial clues about the degradation of the modules. Thus, regular visual inspection of the modules should be carried out for early identification of these defects to detect problems that could lead to failures in the future

Impacts of Rainfall Variability, Land Use and Land Cover Change on Stream Flow of the Black Volta Basin, West Africa

Potential implications of rainfall variability along with Land Use and Land Cover Change (LULC) on stream flow have been assessed in the Black Volta basin using the SWAT model. The spatio-temporal variability of rainfall over the Black Volta was assessed using the Mann-Kendall monotonic trend test and the Sen’s slope for the period 1976–2011. The statistics of the trend test showed that 61.4% of the rain gauges presented an increased precipitation trend whereas the rest of the stations showed a decreased trend. However, the test performed at the 95% confidence interval level showed that the detected trends in the rainfall data were not statistically significant. Land use trends between the year 2000 and 2013 show that within thirteen years, land use classes like bare land, urban areas, water bodies, agricultural lands, deciduous forests and evergreen forests have increased respectively by 67.06%, 33.22%, 7.62%, 29.66%, 60.18%, and 38.38%. Only grass land has decreased by 44.54% within this period. Changes in seasonal stream flow due to LULC were assessed by defining dry and wet seasons. The results showed that from year 2000 to year 2013, the dry season discharge has increased by 6% whereas the discharge of wet season has increased by 1%. The changes in stream flows components such us surface run-off (SURF_Q), lateral flow (LAT_Q) and ground water contribution to stream flow (GW_Q) and also on evapotranspiration (ET) changes due to LULC was evaluated. The results showed that between the year 2000 and 2013, SURF_Q and LAT_Q have respectively increased by 27% and 19% while GW_Q has decreased by 6% while ET has increased by 4.59%. The resultant effects are that the water yield to stream flow has increased by 4%

Land Use and Land Cover Changes under Climate Uncertainty: Modelling the Impacts on Hydropower Production in Western Africa

The Bui hydropower plant plays a vital role in the socio-economic development of Ghana. This paper attempt to explore the combined effects of climate-land use land cover change on power production using the (WEAP) model: Water Evaluation and Planning system. The historical analysis of rainfall and stream flow variability showed that the annual coefficient of variation of rainfall and stream flow are, respectively, 8.6% and 60.85%. The stream flow varied greatly than the rainfall, due to land use land cover changes (LULC). In fact, the LULC analysis revealed important changes in vegetative areas and water bodies. The WEAP model evaluation showed that combined effects of LULC and climate change reduce water availability for all of demand sectors, including hydropower generation at the Bui hydropower plant. However, it was projected that Bui power production will increase by 40.7% and 24.93%, respectively, under wet and adaptation conditions, and decrease by 46% and 2.5%, respectively, under dry and current conditions. The wet condition is defined as an increase in rainfall by 14%, the dry condition as the decrease in rainfall by 15%; current account is business as usual, and the adaptation is as the efficient use of water for the period 2012–2040

A review of hybrid renewable energies optimisation: design, methodologies, and criteria

Over the years, several achievements have been made in power generation and optimising hybrid renewable energy systems (HRES) to achieve nature conservation, achieve energy security, and reduce carbon emissions. However, there are many complexities in Renewable energy (RE) conversion, sizing, design, and implementation, that require optimisation techniques to achieve optimal results in terms of reliability, cost, and environmental protection over time. This paper presents an overview of research trends in Optimization methods in HRES which are classified into modern and conventional methods. These two classifications are further divided into control methods, Artificial intelligence, Iterative and mathematical operations. However, all mentioned techniques have inherent advantages and disadvantages which will be discussed in this survey. In addition, the review paper explored different types of research in computing intelligence (CI), an aspect of Artificial Intelligence (AI) that involves the development of nature-inspired algorithms for optimisation. Finally, general optimisation criteria, system sizing methods used in RES, Mathematical modelling of RES, and gaps for future work to achieve sustainability were also presented

Modeling climate change impact on inflow and hydropower generation of Nangbeto Dam in West Africa using multi-model CORDEX ensemble and ensemble machine learning

Climate change (CC) poses a threat to renewable hydropower, which continues to play a significant role in energy generation in West Africa (WA). Thus, the assessment of the impacts of climate change and climate variability on hydropower generation is critical for dam management. This study develops a framework based on ensemble climate models and ensemble machine learning methods to assess the projected impacts of CC on inflow to the reservoir and hydropower generation at the Nangbeto Hydropower plant in WA. Inflow to reservoir and energy generation for the future (2020–2099) is modeled using climate models output data from Coordinated Regional Downscaling Experiment to produce a publicly accessible hydropower dataset from 1980 to 2099. The bias-adjusted ensemble mean of eleven climate models for representative concentration pathways (RC4.5 and RCP8.5) are used. The added value of this approach is to use fewer input data (temperature and precipitation) while focusing on their lagged effect on inflow and energy. Generally, the model output strongly correlates with the observation (1986–2005) with a Pearson correlation of 0.86 for energy and 0.82 for inflow while the mean absolute error is 2.97% for energy and 9.73% for inflow. The results reveals that both inflow and energy simulated over the future periods (2020–2039, 2040–2059, 2060–2079, and 2080–2099) will decrease relative to the historical period (1986–2005) for both RCPs in the range of (2.5–20.5% and 1–8.5% for inflow and energy, respectively), at annual, monthly and seasonal time scales. Therefore, these results should be considered by decision-makers when assessing the best option for the energy mix development plan