Research Articles

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Geochemical assessment and pollution evaluation of stream sediments’ quality impacted by industrial activities at Suame Magazine area, Kumasi, Ghana.
(Springer Nature, 2023-03-18) Adu-Gyamfi, J., Nyantakyi, E. K., Borkloe, J. K., Agbotui, P. Y., Yeboah, S. I. I. K., Ackerson, N. O. B., ... & Gyamfi, E.
Heavy metal pollution in industrial and residential areas in cities has become a salient environmental issue in Ghana. However, high-quality and environmental investigations of stream sediments are essential for the evaluation of contamination and subsequent decision-making processes. The study was undertaken to identify possible heavy metals and their concentrations in stream sediments from Suame Magazine and its environs in Kumasi, Ghana. Soil samples were analysed for vanadium (V), chromium (Cr), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), lead (Pb), tin (Sn), strontium (Sr), zirconium (Zr), barium (Ba), gallium (Ga), yttrium (Y), titanium (Ti), manganese (Mn) and iron (Fe) using a polarized energy-dispersive X-ray fluorescence (PED-XRF) stream sampling, elemental analyses of heavy metals and state of pollution evaluation using contamination factor (CF), enrichment factor (EF) and geo-accumulation index (Igeo), while pollution load index (PLI) for the north and south sides of the cluster and source provenance of the trace elements were undertaken. The results showed that elements such as Cr, Zn, As, Pb, Sn and Zr were enriched by anthropogenic activities and exceeded the maximum allowable limits, while V, Ni, Cu, Ba, Y, Mn, Sr, Ti, Co, Fe and Ga were not. The results also showed that the north side of the study area was relatively more polluted in trace elements than the south indicative of contaminated stream sediments. The likely pathways from the Suame Magazine and the contaminated stream sediments to sensitive receptors like humans, plants, animals and the environment need to be sequestered and isolated. In addition, government like the Municipal Health Directorate must be informed of this study so that it will affect public and epidemiological studies, interventions and policy.
Delineation of preferential flow pathways in a typica crystalline rock quifer in Takwa, Ghana using integrated hydrogeo
(IWA Publishing, 2023-04-29) Agbotui, P.Y, Ewusi, A., Seidu J., Brookman-Amissah, M., Woode, A., Aforla, B.
Delineation of preferential flow pathways in a tropical crystalline rock aquifer in Tarkwa, Ghana using integrated hydrogeophysical methods
(IWA, 2023) Agbotui, P. Y.; Ewusi, A.; Seidu, J.; Brookman-Amissah, M.; Woode, A.
In Ghana, crystalline rock aquifers with secondary hydraulic features and preferential flow pathways serve as very important aquifers. Protecting and managing these geological porous media require identifying preferential flow pathways and hydraulic characteristics. In this study, preferential flow pathways and hydraulic parameters were characterised for two boreholes (Hilly and Valley) located in Tarkwa, Ghana via the integrated use of borehole dilution testing (BDT), slug testing, and geological mapping. The geological fieldwork mapped a relatively sparsely fractured Sandstone Unit overlying a heavily foliated and fissile Phyllite Unit. Geology influenced groundwater flow in boreholes. The BDT confirmed the geology by showing a stratified flow system with preferential flow pathways. The Hilly/recharge area borehole shows relatively low downward flow, whereas the Valley/transition area borehole is dominated by the concentrated diffuse horizontal flow. These flow patterns are in agreement with the borehole locations and their dominant geologies. The estimated hydraulic conductivity, transmissivity, and storage coefficient ranged between 5.1 104 –7.7 102 m/d, 4.0 102 –3.2 m2 /d, and 107 –105 , respectively. The cheap integrated hydrogeophysical methods used in this study are applicable for characterising, protecting, and managing other crystalline aquifers in the West African sub-region and other tropical terrains.
Estimation of Shipping Emissions in Developing Country: A Case Study of Mohammad Bin Qasim Port, Pakistan.
(International Journal of Environmental Research and Public Health, 2022) Hussain, I.; Wang, H.; Safdar, M.; Ho, Q. B.; Wemegah, T. D.; Noor, S.
Transportation has the highest dependence on fossil fuels of any sector and accounts for 37% of carbon dioxide (CO2) emissions. Maritime transportation is responsible for around 940 million tons of CO2 and approximately 3% of global emissions annually. The significant increase in shipping activities around the globe has magnified the generation of toxic pollutants. In recent years, shipping emissions have received significant attention in developed countries due to global climate change, while in developing countries, researchers are making enormous efforts to tackle this catastrophic and pressing issue. This study considers Muhammad Bin Qasim Port (MBQP), Karachi, Pakistan as a case study. This study employed an activity-based or bottom-up approach with a standard procedure to estimate the various anthropogenic pollutants emissions including particular matters (PM10 and PM2.5), nitrogen oxide (NOx), sulfur dioxide (SO2), carbon monoxide (CO), CO2, methane (CH4), non-methane volatile organic compound (NMVOC), and hydrocarbon (HC) under different operational modes, i.e., hoteling, maneuvering, and reduced speed zones. The results indicated that CO2 was the highest contributor with a proportion of 92%, NOx 5%, and SO2 1.5% for all three operational modes. Moreover, the results indicated that container ships account for 64% of overall emissions, followed by tankers for 24%. Regarding the monthly trend, the findings revealed that November and December had the highest emission rates, with over 20% of the total emissions recorded. This study’s findings will assist stakeholders and policymakers to prioritize maritime emissions in developing countries.
Enhancing food waste compost quality with nutrient amendments.
(Journal of Recycling Organic Waste in Agriculture, 2022) Nkansah, J. B.; Oduro-Kwarteng, S.; Essandoh, H. M. K.; Kuffuor, R. A.
Purpose Recycling of food waste fraction of municipal solid waste into compost for use in agriculture is seen as an effective environmentally–friendly option. In developing countries, however, there are few commercial composting facilities producing composts whose use in agriculture is low, mainly due to their low nutrient content compared to chemical fertilizers. Method This study investigated the effect of the food waste (FW) nutrient-amendment ratio on compost quality using amendments such as Cocoa Pod Husk Ash (CPHA), poultry manure (PM), and cow manure (CM). Six treatments (T1, T2, T3, T4, T5, and T6) and control were composted for 70 days. Results The total Nitrogen, total Phosphorous, and total Potassium content ranged from 0.96–1.42%, 0.19–0.78%, and 0.86-1.42%, respectively, for the different compost types. In all treatments, the C/N ratio reduced significantly, while concentrations of heavy metals (Pb and Zn) were within the acceptable international limits. Toxicity of composts to cucumber (Cucumis sativus) was ascertained. Germination index (GI) was the highest in T5 (FW amended with PM only) whereas the control (FW only) recorded the least GI. Conclusion This study shows that the use of PM, CM, and CPHA seems to be beneficial for the enrichment of food waste compost.
Quantifying and analysing water trade-offs in the water-energy-food nexus: The case of Ghana.
(Water-Energy Nexus, 2022) Opoku, E. K.; Adjei, K. A.; Gyamfi, C.; Vuu, C.; Appiah-Adjei, E. K.; Odai, S. N.; Siabi, E. K.
Water, Energy and Food (WEF) are inextricably linked, and the Water-Energy-Food nexus (WEF nexus) provides a comprehensive framework for addressing the complex and intricate interconnections in the development of these invaluable resources. Quantifying the interconnections among energy, water, and food sectors is a preliminary step to integrated WEF systems modelling, which will further contribute to robust WEF security management. However, the use of the WEF nexus concepts and approaches to systematically evaluate WEF interlinkages and support the development of socially and politically relevant resource policies in Ghana has been limited. This study sets the pace in the development of WEF nexus research in Ghana to facilitate policy and decision-making in the WEF sectors in the country. The study aimed at quantifying the existing water trade-offs in the WEF nexus and also model the trade-offs considering basic development scenarios. The water intensities of food production and energy generation in Ghana were found to be 990 m3/tonne and 2.05 m3/kWh respectively. Scenario analysis was done to project future annual water requirements for food production, energy generation as well as socio-domestic WEF demands based on two possible development scenarios. The analysis predicts that with business as usual, the annual water requirements for food production and energy generation as well as domestic sustenance in Ghana would increase by 34% in 2030. However, technological advancements and innovation in the energy and food sectors could reduce annual water requirements by over 26% even when 100% access to electricity is achieved nationwide.
Evaluation of potential evapotranspiration assessment methods for hydrological modelling with SWAT in the Densu river basin in Ghana.
(International Journal of Environmental Science and Technology, 2022) Adjei, F. O.; Obuobie, E.; Adjei, K. A.; Odai, S. N.
Accurate estimation of evapotranspiration (ET) is required for a good estimation of available water for use in any catchment as ET constitutes major means by which water is lost in any catchment. SWAT model uses climate data in estimating potential evapotranspiration (PET). The PET together with other parameters is then used in estimating actual evapotranspiration (AET). SWAT model provides three different methods in estimating PET which are Penman–Monteith (PM), Hargreaves (H) and Priestly–Taylor (PT). These three PET methods were evaluated in a limited available spatial and temporal data Densu river basin to assess their impact on the resulted model water balance. The missing data in the 8 climate stations that were used in this study were estimated using a WXGEN weather generator. The results showed that the accuracy of the water balance from the SWAT model was defined by how well the PET method selected for the SWAT was able to estimate an accurate spatial and temporal distributed PET in the basin. A discharge at Nsawam, a town within the basin, was used for the model calibration and validation. Hargreaves PET method had the best Nash–Sutcliffe model efficiency coefficient (NSE) values of 0.70 for the calibration and 0.74 for validation period, while the PM PET method had the worse NSE value of 0.66 for calibration and 0.62 for validation. These results were attributed to the limited available data within the basin. The discrepancies in the resultant water balance model could be attributed to the three different PET methods used in relation to the climate data that were available for the calibration and validation of the SWAT model.
Modelling the recent variations of water balance components and water availability within the Senegal River basin: using WEAP21 model.
(Modeling Earth Systems and Environment, 2022) Thiam, M.; Adjei, K. A.; Niang, A.; Gyamfi, C.; Odai, S. N.; Kane, A.
The availability of water in the Senegal River basin is a basic issue for moving towards efficient resource management. Given the extent of the river and the large number of stations, hydrological modelling is a reliable means of assessing the evolution of the water balance and availability over the last 30 years. This paper aims to evaluate water balance components and to model the water balance over the Senegal River basin from 1989 to 2020. The streamflow data have been calibrated and validated with the PEST program incorporated in WEAP with a NSE equal to 0.98, a PBIAS of 7% and a R2 of 0.98. The water balance has been computed using the Soil Moisture Method which use mainly climate data and runoff data to output different results driving to an analysis of the water balance components. The results have shown that the precipitation is the main alimentation of the river with a mean rainfall of 267,255.84 Mm3; the losses by evapotranspiration are 246,892.45 Mm3. According to the conventional formula, the water balance would be equal to 20,363.38Mm3 in the Senegal River basin. The modelling of the water balance in this basin will allow a further study concerning the effect of climate change on the hydrological and ecological system of the Senegal River basin. A variation in the resource and hydrological parameters was noted. Although the 30 years see a decrease in rainfall, runoff increases. However, it remains to integrate the water use parameters for better conclusions.
Impacts of climate change on crop and irrigation water requirement in the Savannah regions of Ghana.
(2022) Incoom, A. B. M.; Adjei, K. A.,; Odai, S. N.; Akpoti, K.; Siabi, E. K.
Irrigation is important for food security, however, water requirements for sustainable irrigation may be affected by climate change. The study analysed water requirements of two commonly cultivated crops in the dry season in the Ghanaian Savannah regions under baseline and future periods. Crop water requirement (CWR) and crop irrigation requirement (CIR) were lowest in baseline periods and increased in the 2020s, 2050s, and 2080s for RCP 4.5 and RCP 8.5 at all locations. CIR was higher for tomato as compared to onions for most locations. Seasonal changes in the CWR ranged from 2–9, 3–12, and 3–12% and 2–8 3–12% and 5–18% for the 2020s, 2050s and 2080s under RCP 4.5 and RCP 8.5, respectively, for both the crops. Bole and Zuarungu recorded highest increases in CWR for tomato, whereas the least change was observed at Yendi for onions. Changes in seasonal CIR ranged from 3–19, 2–21, and 6–22%, respectively, for the 2020s, 2050s and 2080s for RCP 4.5. Under RCP 8.5, changes in seasonal CIR ranged from 3–23, 5–23, and 6–27% were observed for the 2020s, 2050s, and 2080s, respectively. Highest increases in CIR were noticed at Bole and Zuarungu for tomato, whereas the least change was observed at Wenchi for onions. Findings of the study support zero hunger and climate action, goals 2 and 13 of the Sustainable Development Goals (SDGs).
Implications of land use/land cover changes and climate change on black volta basin future water resources in Ghana.
(Sustainability, 2022) Abungba, J. A.; Adjei, K. A.; Gyamfi, C.; Odai, S. N.; Pingale, S. M.; Khare, D.
The Black Volta River basin faces several challenges, which impede the sustainability of its water resources and biodiversity. Climate change coupled with land use/land cover (LULC) change patterns account for most of the observed hydrological changes in the basin. The aim of this study was to assess the impact of changes in the climate and LULC on water resources in the basin, and its effect on the livelihoods of downstream users, particularly regarding water allocations. The water evaluation and planning (WEAP) model was applied to the assessment of runoff and streamflow and the percentage future water demand under climate change scenarios (RCP 2.6 and RCP 8.5), as well as the effects of current and future changes on water supply systems. LULC data from 1990 to 2019 were processed to detect the changes in LULC patterns in the basin. The results showed that from 1990 and 2019, the land use classes of settlements/bare ground, open savannah woodland, croplands, and waterbodies increased by 339.5%, 77.4%, 24.4%, and 607%, respectively. Close savannah woodlands, wetlands, and grasslands all decreased by 97%, 99.8%, and 21.2%, respectively. Overall, there was a significant difference in LULC changes. Hence, measures needed to be put in place to curb the changes, as the observed changes posed a serious challenge to the basin’s water resources. The results from the WEAP simulations also indicated that in the future, changes in discharge would be visible in September with ranges between 0.72 × 106 m3 and 1.9 × 106 m3 for RCP 2.6, and 0.65 × 106 m3 and 2.5 × 106 m3 for RCP 8.5, per month. Although the median values illustrate an increase in water availability from river discharge compared with the reference scenario, the uncertainties in future changes largely exceeded the predicted increases. Annual variability of the mean annual flows is projected to decrease over the period in the Black Volta Basin. Therefore, the outcomes of this study will be useful for different stakeholders within the basin in water resources planning and the formulation of appropriate policies for improving land use planning.
A review of water charges: customers’ perception of the quality of the levels of service in Ghana, the water charges and their willingness to pay for improved services.
(Journal of Research in Humanities and Social Science, 2016) Gyabaah, F.; Amankwah-Minkah, A.; Agbotui, P. Y.
The trade-off between full cost recovery and providing the urban poor with potable water in the right quantity, quality and at affordable prices is ever increasing especially in African countries. Ghana, not being an exception continues to struggle in its efforts to provide safe drinking water to the urban populace and Ghana Water Company Limited (GWCL), the urban water service provider stands at the centre of this ordeal. The company has been criticised for being inefficient in its management of the urban water supply due to various reasons - technical, financial and political. This report reviews the water supply management in Ghana. It further investigates by way of a survey, the perception of consumers in Ghana of the quality of the levels of service offered them regarding water quality, quantity and reliability, as well as the affordability and willingness to pay for improvements in the water services rendered by the GWCL. The survey came up with one hundred and thirty-four (134) valid respondents – 56 directly handed out printed questionnaire respondents and 78 online respondents. The survey results show that most customers perceive the water quality and reliability of the service received as being average and above, although over 78% of them have their water supply interrupted at least once every week. The quantity of water received is shown as not being adequate, since 54% of customers resort to other sources of water to supplement public supply. Even though the water quality is rated as good, customers rarely drink water from this service, as 66.4% of them prefer drinking sachet or bottled water. Most consumers (63.4%) think the current water prices are high and only about 3% are willing to pay more to achieve full cost of water service and for a significant improvement to the supply system. The water supply situation in Ghana should be recognized as a national issue and given higher priority. Major reforms need to be made in both policy and practice if the levels of service are to match up to internationally accepted standards. This would bring significant public health improvements and service improvements to wider Ghanaian society
Causes of delays in highway construction projects in Ghana
(Civil and Environmental Research, 2016) Aforla, B.; Woode, A.; Amoah, D. K.
Delays in construction projects are a global phenomenon, causing a multitude of negative effects on the key project participants – clients, consultants, and contractors. The main purpose of this study is to identify the causes of delay of highway construction projects in Ghana to determine the most important to the key project participants. Literature review and semi-structured interviews of 12 key players in the implementation process were conducted. Thirty five possible causes of delay were identified and further grouped into ten categories. A questionnaire survey was conducted on the resulting list of delay causes for the identification of the most important causes of delay. The relative importance of the individual causes were determined and ranked by their Relative Importance Index. The findings revealed that the five most important causes of delay in road construction projects in Ghana are 1) Delay in honouring payment certificates 2) Equipment failure 3) Shortage of materials 4) Poor site management 5) Late delivery of materials on site. It is hoped that the findings of this paper will help project participants to act on critical causes to minimize delay of their projects.
Study of brick mortar using sawdust as partial replacement for sand.
(Journal of Civil Engineering and Construction Technology, 2017) Sasah, J.; Kankam, C. K.
The paper reports results of study on standard masonry mortar containing sand and sawdust as aggregates in a mix proportion of 1:3 and water-cement ratio of 0.55. A modified mortar of same design mix proportion (1:3) but varying water/cement ratio and constant slump of 74.3 mm to achieve higher workability was also evaluated. Six different percentages (5, 10, 15, 20, 30 and 50%) of sand replacement were investigated. The flexural tensile strength, compressive strength, dry density, masonry wallet compressive strength, water absorption and slump were evaluated. The British code recommended masonry wallet compressive strength of 5.3 N/mm2 was achieved with 8 and 13% sawdust contents in the standard and modified mortars, respectively. Such mortars can be used as jointing and rendering materials on interior walls of buildings where water absorption by the mortar would be reduced. Key words: Sawdust, mortar, wallet, masonry compressive strength, water absorption
Biotite influence on the binding properties of bituminous materials.
(International Journal of Engineering Research & Technology (IJERT), 2017) Aforla, B.; Woode, A.; Amoah, D. K.; AY, B. S.
The effect of biotite on rheological properties of bitumen was investigated using biotite extracted from gneiss rocks. The research methodology involves two phases. The first phase involves the separation of biotite from gneiss rock. The second phase involved tests carried out on bitumen- biotite blend to determine the effect of biotite on the rheological properties of bitumen. The biotite was ground to 75Âµm size and blended with bitumen AC-10 prepared in various proportions and the rheological properties determined in the laboratory. The results of this study shows that biotite improves the binding properties of bitumen. At low temperatures, the presence of biotite in bituminous mixtures in the proportion of 2 to 3.5% by weight of bitumen improves the binding properties. Conversely, at higher temperatures of about 135oC, the biotite bitumen mix showed best result at 2%. An increase of up to 3.5% by weight of biotite resulted in a drop in the kinematic viscosity values even though there was an improvement in the binding properties over the pure AC-10 bitumen results.
Study of recycled polyethylene plastic waste as binder in building block for greener construction.
(International Journal of Trend in Research and Development (IJTRD), 2018) Kankam, C. K.; Ansa-Asare, K.; Meisuh, B. K.; Sasah, J.
Plastic production has overtaken most man-made materials including metals and has long been under environmental scrutiny. Most plastic wastes are accumulated in landfills, natural environment and oceans. It is estimated that with the current trend of global production and waste management, approximately 12000 million metric tons of plastic waste will accumulate in landfills and in the natural environment by the year 2050. Plastics have very poor recycling rates, and their inherent menace is most pervasive in low-income, developing countries. This paper presents results of study on plastic waste as binder in mixtures of sand (fine aggregates) to produce building blocks for construction. Melted polyethylene plastic was mixed with sand (sandplast) in different proportions of 1:1, 1:1.5, 1:2, 1: 2.5 and 1:3 (plastic: sand). Test results include compressive, tensile and impact strengths, stress-strain response, fire resistance, water absorption and permeability of sandplast. The optimum mix ratio for the compressive, tensile and impact strength was 1:2. The compressive and tensile strength of sandplast blocks ranged from 4.8 to 7.4 N/mm2 and 3.3 to 7.2 N/mm2 respectively. These are greater than the respective values for sandcrete blocks produced in Ghana that generally vary from 1.4 to 3.5 N/mm2 and 0.1 to 0.3 N/mm2 . The static modulus of elasticity of sandplast averaged approximately 89.0, 311.5 and 197.7 N/mm2 for mix proportions of 1:1, 1:2 and 1:3. At temperatures below 80oC the strength properties and stability of sandplast blocks remained unchanged. When immersed in water, sandplast blocks were found to be insoluble in water. The coefficient of permeability of sandplast averaged 4.6 x 10-4 , 8.2 x 10-4 and 21.8 x 10-4 cm/sec for mix proportions 1:1, 1:2 and 1:3 respectively.
Flood risk assessment and mapping in Abidjan district using multi-criteria analysis (AHP) model and geoinformation techniques (Cote d’ivoire).
(Geoenvironmental Disasters, 2016) Danumah, J. H.; Odai, S. N.; Saley, B. M.; Szarzynski, J.; Thiel, M.; Kwaku, A.; Akpa, L. Y.
Background: Flood is one of the most destructive natural disasters of climate change effects in West Africa. Flood risk occurrence is a combination of natural and anthropogenic factors, which calls for a better understanding of its spatial extent. The aim of this paper is to identify, and map areas of flood risk in Abidjan district. Results: This work is based on the integration of multi-criteria data including slope, drainage density, type of soil, Isohyet, population density, land use and sewer system density within ArcGIS interface. The resulting AHP flood risk map shows that areas under high and very high flood risk covers 34 % of the study area. Conclusion: The Analytic Hierarchy Process (AHP) method used as a multi-criteria analysis allowed the integration of several elements under two criteria, hazards and vulnerability, for flood risk assessment and mapping. Results revealed that, Abidjan district is heavily exposed to the risk of flooding. Eight out of thirteen (8/13) municipalities within the district are at a high risk of flooding which calls for decision makers to effectively develop strategies for future flood occurrences within the Abidjan district (South of Côte d’Ivoire).
A stochastic weather generator model for hydroclimatic prevision in urban floods risk assessment in Abidjan District (Cote d’Ivoire).
(Sustainability, 2016) Danumah, J. H.; Odai, S. N.; Saley, M. B.; Szarzynski, J.; Adjei, K.; Kouame, F. K.
Flood risk occurrence is very often related to heavy precipitation; and available future weather data is a potential source for long term flood risk prediction. The aim of this paper was to determine and analyze trends in rainfall, temperature and PET under present and future climatic conditions using Long Ashton Research Science-Weather Generator (LARS-WG) software, in prediction of flood risk occurrence in Abidjan. This work was based on the integration of Hydro climatic daily data within LARS-WG software. The processing steps are: (1) calibrating and validating the model using 50 years measured data, (2) generating baseline data for 50 years, (3) processing future scenario data based on baseline already set using HADCM3 and (4) Comparing baseline and generated scenario data. The resulting statistics show that temperature will increase by 0.32, 1.36 and 2.54 °C for the periods 2011–2030, 2046–2065 and 2080–2099 respectively. Then rainfall in the same period will increase by 4 %, 6 % and 10 % respectively. The mean and high flooding risk will then increase in long term within this urban area. Thus this future large extension of flooding occurrence imposes to take future weather scenario into account in prediction and management of flooding risk in Abidjan District.
Change and Analysis of Extreme Rainfall Indices During 1960–2010 and 2011–2100 in Abidjan District (Côte d’Ivoire).
(Climate Change Research at Universities, 2017) Danumah, J. H.; Odai, S. N.; Saley, M. B.; Akpa, L. Y.; Szarzynski, J.; Kouame, F. K.
Flood risk occurrence is very often related to heavy precipitation. The availability of analysis of weather data is a potential source for long term flood risk prediction and management. The aim of this paper was to determine and analyse trends of observed and future rainfall indices from 1961 to 2010 and 2011 to 2100 using rclimdex model in Abidjan District. This work was based on the integration of daily weather data within rclimdex model throughout quality control test, homogeneity test and indices calculation of ten (10) rainfall indices. The results showed an overall decrease trend of the rainfall indices namely through a negative trend in the annual total rainfall, maximum number of consecutive wet days, and number of extremely wet days during the period from 1961 to 2010. Exception was made from 1995 to 2010 where the same indices showed a positive trend. However, the results have showed also an increase trend of consecutive wet days (CWD), Simple daily intensity index (SDII) and Number of heavy precipitation days (R10) indices from 2011 to 2100. Thus these findings explain the nowadays flood occurrence and indicate that rainfall extreme under flood risk events will continue in the future. Therefore it call decision makers for preparedness and mitigation strategies in Abidjan District.
A quantitative groundwater resource management under uncertainty using a retrospective optimization framework.
(Sustainability, 2017) Kifanyi, G. E.; Ndambuki, J. M.; Odai, S. N.
Water resources are a major concern for any socio-economic development. As the quality of many surface fresh water sources increasingly deteriorate, more pressure is being imparted into groundwater aquifers. Since groundwater and the aquifers that host it are inherently vulnerable to anthropogenic impacts, there is a need for sustainable pumping strategies. However, groundwater resource management is challenging due to the heterogeneous nature of aquifer systems. Aquifer hydrogeology is highly uncertain, and thus it is imperative that this uncertainty is accounted for when managing groundwater resource pumping. This, therefore, underscores the need for an efficient optimization tool which can sustainably manage the resource under uncertainty conditions. In this paper, we apply a procedure which is new within the context of groundwater resource management—the Retrospective Optimization Approximation (ROA) method. This method is capable of designing sustainable groundwater pumping strategies for aquifers which are characterized by uncertainty arising due to scarcity of input data. ROA framework solves and evaluates a sequence of optimization sub-problems in an increasing number of realizations. We used k-means clustering sampling technique for the realizations selection. The methodology is demonstrated through application to an hypothetical example. The optimization problem was solved and analyzed using “Active Set” algorithm implemented under MATLAB environment. The results indicate that the ROA sampling based method is a promising approach for optimizing groundwater pumping rates under conditions of hydrogeological uncertainty.
Micro-level social vulnerability assessment towards climate change adaptation in semi-arid Ghana, West Africa
(Environment, Development and Sustainability, 2018) Badmos, B. K.; Adenle, A. A.; Agodzo, S. K.; Villamor, G. B.; Asare-Kyei, D. K.; Amadou, L. M.; Odai, S. N.
This study determined the social vulnerability index (SoVI) of households to climate change impacts for three identified locations (upper, mid and lower) in the Vea catchment, semi-arid Ghana. This study adapted the social, economic and demographic indicator approach. The data used were obtained from a survey of 186 randomly sampled farm households and direct field measurements of 738 farm plots belonging to the same sampled farm households. Information from the literature, expert judgement and principal component analysis were useful for computing and analysing the SoVI. The variables were normalized, weighted and subsequently recombined to determine the index of the three locations towards climate change. Although the SoVI to climate change was highest (0.77) for the upper part of the catchment, the mid- and lower parts of the catchment show a high SoVI of 0.72 each. The overall SoVI for the catchment is 0.73. The study re-emphasizes the high vulnerability level of dry areas to climate change. Moreover, it shows there is variability at micro-scale. There is a need to put appropriate measures to address the vulnerability of households to climate change in the semi-arid areas of West Africa. Factors aggravating dry land’s vulnerability towards climate change should be prevented with implementable policies. Furthermore, it is important to identify conditions that have made some areas less vulnerable to climate change, and then, we can work out the possibility of adapting such to the vulnerable places.

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