ghanaopendata/ghanaian-research-english huggingface dataset:
Estimation of planetary boundary layer height from radiosonde profiles over West Africa during the AMMA field campaign: Intercomparison of different methods

Deducing realistic planetary boundary layer heights (PBLH) is crucial for weather, climate and air quality models, despite its equivocal nature. In this paper, a comparative assessment of seven PBLH estimation methods has been performed, with radiosonde profiles taken during the African Monsoon Multidisciplinary Analyses (AMMA) project campaign from June, 2006 to July, 2007 over 18 locations in West Africa. First, PBLH was identified from the radiosonde profiles as the location of minimum gradients in mixing ratio (q), relative humidity (RH) and refractivity (N), and maximum gradient in potential temperature (θ). Other methods used to identify PBL tops were the statistical NS method and bulk Richardson (Rib) method at a critical threshold of 0.25. Next, a reference method (ho) was identified as the benchmark for PBL comparison. Visual inspection of the individual profiles allowed for assessing the ho method to yield reliable PBLH estimates. Thereafter, comparisons of the PBLH were performed for both convective and stable cases, with the stable boundary layer (SBL) height being generally below 700 m a.g.l for all methods, whereas, convective boundary layer (CBL) heights ranged between 300 m a.g.l and 1400 m a.g.l across different regions of the study area. Contrarily, the NS method failed to detect the SBL due to its inability to identify a dewpoint or virtual potential temperature discontinuity. Additionally, the Rib method, particularly in stable cases, yielded PBL tops consistent with the reference method (ho) whenever the NLLJ was clearly defined due to contribution of wind shear beneath the jet core to turbulent kinetic energy (TKE) production. Afterwards, the study domain was split into three zones and the performance of each method was assessed per each zone. Spatially, the CBL height was observed to grow thicker in the north-east direction over the dry, arid regions, where integral values of sensible heat rapidly converted by surface net radiation, has significant influence on the growth of CBL throughout daytime. Other likely reasons for this observation are advection, orography and mechanical turbulence production. However, a reversal was observed at night with the SBL being thinner in the dry, arid regions and rather relatively, higher in the coastal regions. Finally, the statistical assessment, coupled with visual inspection of the individual profiles, showed that the gradient methods (particularly N) outperformed the Rib and NS methods, yielding very low biases as well as, high and statistically significant correlation co-efficients. These results are useful for enhancing the performance of PBL models over the region. Possible limitations to the findings of this study are the different ascent times between the sites, as well as the number of ascents per site, which ∗ Corresponding author.

Source: KNUST
Estimation of Soil Moisture Content Using GPR and Time- Lapse Resistivity: A Case Study of KNUST Anwomaso Oil Palm Plantation

The viability of the ground penetrating radar (GPR) and time lapse resistivity measurements to assess the temporal and spatial variation of the volumetric water content in soil was tested in this work at the KNUST Agricultural Research station at Anwomaso - Kumasi. In the case of the GPR, the surface water content was measured with the ground wave, which is a direct wave between the transmitter and receiver through the upper centimeters of the soil. Spatial water content variation was measured on a 32 day monitoring period along four (4) 82 m profile lines. Electrical resistivity tomography (ERT) was used to measure resistivity at the experimental site with the objective of quantifying soil moisture for 20 days. This was based on the fact that, the degree of water saturation affects the resistivity measured hence water moisture could be imaged from the resistivity measurements. The time-series data set was used to generate desaturation models. It was observed from the results that rainfall affects the volumetric soil water and the resistivities measured. It was concluded that the non-invasive GPR measurements provide the means to accurately and consistently monitor the spatial water content variation in time at shallow depths with water content ranging from 0.06 m3/m3 to 0.4 m3/m3 whereas resistivity measurements are useful in imaging the moisture content at deeper depth.

Source: KNUST
Estimation of the rate of sediment transport into the Bui hydropower reservoir

The knowledge of sediment yields in water infrastructures like reservoirs is necessary to be able to plan for long-term water resources development and management. The Black Volta Basin houses the recently constructed hydropower reservoir at Bui, which supplies 400 MGW of power to the national grid, but lacks recent sediment information for outstanding changes in sediment transport and sedimentation in the Bui reservoir. This study analysed the current rate of sedimentation in the Bui reservoir by establishing discharge and sediment rating curves at Chache (upstream of the reservoir) and Bamboi (downstream of reservoir), and using empirical equations together with suspended sediment data collected through a one year (2014/2015) monitoring programme. The results show maximum suspended sediment concentrations of 328.15 mg/l and 51.28 mg/l measured at Chache and Bamboi, respectively. This gives an indication that the Bui reservoir is effective in trapping sediment from upstream of the reservoir catchment area. Current gross annual sediment yield in the reservoir was estimated at 1,370,007 t/yr. Compared to the designed rate of sediment yield for the reservoir (968,000 t/yr), the current estimate depicts an increase in annual sediment yield of about 41.5 %, which has negative impact on hydropower generation, aquatic life including fishery, and the lifespan of the reservoir. The increase in sediment yield over the designed figure could worsen in the near future if changes in land use, particularly illegal small scale mining activities upstream and close to the reservoir are not properly managed by regulating or enforcing the laws governing illegal small scale mining.

Source: KNUST
Estimation of the Probability of Default of Consumer Credit in Ghana: Case Study of an International Bank

This thesis uses empirical data on customer credit information to model probability of loan default in Ghana. We have constructed the logistic regression model using a dataset from an international bank in Ghana, Bank A. 9939 observations of customers were recorded of which 14% turned out to default their loan. The analyses are performed using logistic regression, with SPSS program. Six variables were found to be highly significant in the model. These are Marital Status, Number of months the applicant has been in current employment, interest rate, tenure of loan, income level and loan amount. The model was used to predict successfully the probability of default of an applicant. Applicants who are not married are 1.24 times more likely to default than those who are married. Lower income earners are more likely to default compared to higher income earners. Those who have been in their current employment for longer period are more likely to repay their loans. A unit increase in the number of months in current employment reduces the probability of default by 0.998.

Source: KNUST
Estimation of Total Arsenic in Maize, Fish and Human Urine from Some Parts of Amansie West District in the Ashanti Region of Ghana

Amansie West District is a gold mining area in the Ashanti Region of Ghana and the method of mining used is surface mining. From the operation of mining activities (galamsey) arsenic is released into the atmosphere and water bodies in the environment. Consequently, the arsenic contaminates the water, soil, and foodstuffs like maize and fish leading to adverse effect on vegetation, animals and humans living in the area. Levels of total arsenic concentration of maize, fish and human urine samples from the district were determined using Varian AA240FS (Fast Sequential AAS) Spectrophotometer and also some physicochemical properties of the samples were determined. The work was conducted between October 2011 and April 2012. The mean total arsenic concentrations in maize ranged from 0.015 to 0.045 mg/kg dry weight. The fish from upstream had levels of arsenic ranging from 1.90 to 3.25 mg/kg dry weight. Mean total arsenic levels in fish from downstream samples ranged from 1.95 to 4.80 mg/kg and the mean total arsenic levels in fish samples from streams and ponds ranged from 1.70 to 3.95 mg/kg. The mean total arsenic in human urine samples ranged from 0.003 to 0.014 mg/l. The pHs of maize, fish from upstream, fish from downstream and fish from streams and ponds ranged from 5.41 to 6.90, 5.34 to 6.87, 5.02 to 6.91 and 5.03 to 7.15respectively. The pH of the urine samples ranged from 5.54 to 8.20. Moisture content of fish from upstream, downstream and streams and ponds ranged from 49.20 to 66.75 %, 56.23 to 65.72 % and 49.43 to 65.98 % respectively Conductivity of the maize varied from 1508 to3371 μS/cm The conductivity of the urine samples ranged from 11691 to 37425 μS/cm. The ash content of maize varied from 15.87 to 20.73 % and for the fish from upstream, downstream and stream and ponds, their ash content ranged from 9.98 to 16.27 %, 9.79 to 15.98 % and 10.68 to 15.92%. The arsenic levels in fish and maize are within the acceptable limits of consumption according to the WHO limit for foodstuffs of 10 mg/kg.

Source: KNUST
Estimation of USLE’s C-factor using vegetation indices (VIs) for soil erosion modelling in Lake Bosumtwi Basin, Ghana.

Water erosion is one of the most challenging environmental problems in Bosumtwi basin; this is due particularly to the rough terrain and human activities on the landscape. The Universal Soil Loss Equation (USLE) is a commonly used model in estimating soil loss by water. The USLE’s cover and management factor (also known as C - factor) represents the combined effects of plant, soil cover and management on erosion. Therefore, this variable keeps changing as soil surface cover keeps changing. The use of remote sensing vegetation index to estimate C - factor proved to be reliable, consistent and useful when considering inaccessible and large regions. The normalized difference vegetation index (NDVI), is the most used algorithm in estimating the C - factor despite the availability of other indices believed to overcome some inherent problems associated with the use of NDVI. This study compares the NDVI to the EVI, in their capability to map land cover types, to be applied in C-factor estimation. Plots of the divergence statistics (derived from ISODATA clustering algorithm in ERDAS Imagine) against class numbers helped determine the optimal numbers the Hypertemporal vegetation index’s (VI’s) images can be classified into. The classification map outputs were reclassified based on the similarities of the profiles generated from the mean annual VI values. The resultant map of the supervised classification was compared to already classified map (produced from a single-date ASTER and data collected from the field) for legends assigning and validation. The overall accuracies of the two VI maps are both high (80 % or EVI and 70% for NDVI) and the kappa statistics of 0.7 and 0.5 for NDVI and EVI respectively. Forty-six (46) 2010 Hypertemporal MODIS EVI were applied in developing an annual C-factor model. In validating the model output; a C-map developed by traditional method – based on EVI classified map and literature assigned C – values - was compared to the C-factor model developed using Exponential Function (E. F) approach. The C-factor model showed an overall accuracy of 76% and 0.6 kappa value.

Source: KNUST
Estimation of vehicular emissions and fuel consumption on road links using HDM-IV in Ghana - A case study on the George Walker Bush Motorway (14.1km) Accra

Fuel consumption and vehicular emissions from traffic are major constraints in sustainable environmental development. Vehicular emissions and fuel consumption have increased in recent years due to rapid growth in world traffic resulting in an increase in associated problems such as cancers, respiratory diseases, global warming etc. Thus, strategies for the reduction of road traffic-generated fuel use and emissions have become issues worth examining. This study looks at the estimation of vehicular emissions and fuel consumption on the 14.1km section of the George Walker Bush Motorway in Accra, Ghana. The Highway Development and Management Tool was used for the estimation of fuel use and vehicle emissions using data from secondary sources. Key data collected were traffic volume and composition, vehicle characteristics, pavement characteristics and climate data of the study area. Three options were analyzed using the HDM-4 software; the base case or do nothing consisted of the road as two-lane asphalt surfaced road with routine maintenance only for the life span of the road. The two project case options were also explored; two lane road with routine maintenance and an overlay in the second year. Also, reconstruction of the road into a 3-lane dual carriageway. This option also will routinely maintain and overplayed in the 10 year intervals. Each project case was analyzed and compared with the do minimum case. The study showed that, total emissions (CO2, CO and NOx) in 2012 on the study road saw a reduction of about 5,056 tonnes for the 3-lane dual carriageway as against the ‘do nothing’ alternative. Comparing with the overlay alternative, the 3-lane dual carriageway also recorded a reduction of emissions (CO2, CO and NOx) of about 3,093 tonnes. On the average, increment in exposure to road users and environment of total CO, CO2, and NOx is expected to be 945.25tonnes per annum for the 3-lane option. Fuel consumptions also recorded reduction of 25.7 litres per 1000veh/km for the 3-lane dual carriageway as against the ‘do nothing alternative’ for small cars and also a reduction of 281.52 litres for heavy trucks. Comparing the 3-lane alternative with the overlay option, again fuel consumption also saw a reduction of 266.021litres per 1000veh/km for heavy trucks and 23.22 litres for small cars. The study also showed a strong correlation between average roughness and yearly emission levels in all alternatives. The study revealed that emissions of CO and NOx by each vehicle class compared with the US Environmental Protection Agency’s standards for Tier 0 and Tier1 vehicle groups were beyond the acceptable limits for human health and environmental sustainability. It was revealed that fuel iv consumption is directly linked to average roughness with a strong coefficient of correlation of 0.9987. Finally, the study also showed that timely overlay interventions gave good results on the 3-lane dual carriageway.

Source: KNUST
Ethical Considerations in Procurement Management and its effects on Public Procurement (Greater Accra Region, a Case Study in Accra Metropolis)

To deliver public service effectively and efficiently, in addition to achieve value for money for taxpayers, governments of developed and developing countries alike spend a lot on goods and services. In Ghana, the Public Procurement plays a dominant role in the economic activities of the country. Public procurement accounts for about 14% of the country’s GDP. However, the area of procurement is increasingly prone to internal factors which subject the process to many flaws (Trionfetti, 2000). Even though ethics in public procurement has been recognized as one of the contributors to procurement failure, it has not been systematically studied before from the perspective of the factors that influence the ethical considerations in Ghana. The aim of this paper is to present an exploration to the ethical considerations in procurement management and establish their effects on procurement in Ghana’s public sector. By exploring ethical issues from Public sector, this could provide an ethical standpoint for the public project procurement life cycle and could preserve a good affiliation between the Public Sector and the service providers or customers. An extensive literature review was done to obtain secondary data on the subject which gave a good foundation on which the research work was made. The paper employed a case research design. A survey of the selected study population from the Accra Metropolis was carried out by the use of questionnaires through focus group discussions. The sample size of this research was estimated at 40 participants. The findings reveal the complexities of ethical considerations within the Public Procurement process in the country. It highlighted the differences in perceptions of what ethical considerations are; the importance of individual and organizational factors as well as the external factors which comprise the social, political and economic considerations. At the end of the study, it was revealed that ethical considerations in the Public Procurement system are of great significance to the Public Sector as the neglect of this considerations will, if not worsen, give way for increase in adverse ethical issues that will affect the Procurement Systems in the Public Institutions badly and possibly destroy the numerous efforts made for the introduction of the Public Procurement Act, Act 663 to sanitize the procurement system in the public sector.

Source: KNUST
The eutrophication potential of water and sediments of the Tatafo stream in the Mampong Municipality of Ghana

Euthrophication results from increased nutrient loads specifically, nitrogen and phosphorus enrichment in water bodies. The Tatafo stream is one of the direct sources of drinking water for some people in the Mampong-Ashanti municipality and surrounding communities. The stream has been encroached by vegetable growers mainly carrot farmers resulting in pollution of the water body. The Euthrophication potential of both water and sediments of Tatafo stream within the Mampong – Ashanti Municipality was assessed. The levels of pH, electrical conductivity, Total dissolved solids, total suspended solids, biochemical oxygen demand, dissolved oxygen, turbidity, phosphate and nitrate in water, phosphorus and nitrogen in sediments, among others were determined. Three sampling sites were selected along the stream and studied over a period of five months. The results of the study revealed high levels of nitrate above the WHO limits of (5.0 mg/l), upstream samples recorded 7.02 mg/l, 7.33 mg/l in the midstream and 6.61 mg/l in the downstream along the sections of the stream. The findings also revealed that the values of organic matter (0.18%) and organic carbon (0.58%) varied significantly (P < 0.05). However, Turbidity values of 53 NTU at the upstream, 67.9 NTU at midstream and 38.4 at down stream and Total Suspended Solids values ranging from a mean 27.40 mg/l to 132.6 mg/ were all above the World Health Organization limits of 5 NTU and 20 mg/l respectively. Adverse impact on the physico-chemical parameters as a result of vegetable crop farming along the stream poses an environmental and health risk to the people in the Mampong town and nearby communities who rely directly on the stream as the source of water for their domestic use. There is the need for the intervention of appropriate regulatory agencies to check the activities of farmers along the stream and educate people who directly depend on the stream.

Source: KNUST
Evaluating Added Benefits from Combined Cattle Manure and Fertilizer Application in a Maize Cropping System

A field experiment was conducted at Kpongu in the Upper West region of Ghana to determine the added benefits in grain yield of maize derived from the concurrent use of manure and mineral fertilizer, and their cost effectiveness. Factorial combinations of cattle manure and mineral fertilizer each at 0, 50 and 100% of their recommended rates were evaluated in both the field and the laboratory studies. The treatments were applied in a randomized complete block design with three replications on the field. The same treatments were applied in the incubation study in a completely randomized design. The use of 100% NPK (Nitrogen, Phosphorus, Potassium) + 5 t manure gave the highest grain yield of 4,678 kgha-1. Synergistic interactions resulting in added benefits in grain yield were observed in all the combined nutrient inputs except 50% NPK + 2.5 t manure which accrued an added disadvantage of 44 kgha-1. Economic analysis proved that 100% NPK + 2.5 t manure and 50% NPK + 5 t manure were the most economically viable combined treatments in terms of grain yield. Based on the results from this study, resource poor farmers in the Upper West region of Ghana may reduce mineral fertilizer recommended rates by 50% and supplement it with 5 t quality (N >2.5%) cattle manure without compromising yield and profit.

Source: KNUST
Evaluating and modelling the adoption of various health information technology (HIT) data standards. A case study of some selected hospitals

The adoption of health information technology applications can yield real benefits for nations in terms of aspects such as increased delivery of care based on guidelines, enhanced monitoring and surveillance activities, a reduction in medication errors, decreased rates of potentially redundant or inappropriate care, and reductions in the cost of medical services. However, to what extent is health information technology adopted in Ghana. This study thus evaluated the adoption of various health information technology related standards at the decision- making stage of hospitals in Ashanti Region. The research design for the study was cross sectional, with quantitative research approach. The population of the study comprises the staff who used health information technology in the selected hospitals. In all, 260 respondents were sampled from 10 hospitals using purposive sampling technique. The study concludes that, the three main factors (Standard factors, Organisational factors, and Environmental factors) significantly influenced the adoption process of health information technology related data standards in Ghanaian healthcare institutions. Standard factors such as observability of information that is available regarding health data standards, systems integration with existing IT infrastructure, relative advantage of a particular IT standard, and the complexity of using a particular IT standard, greatly influenced hospital’s adoption of a health information technology. Organisational factors such as the type of healthcare organisation (whether private, public, quasi or missionary), availability of data analysis experts, resistance to change, and the size of healthcare organization also influenced the adoption of health information technology. Finally, environmental factors like the existence of national healthcare system policy by government, and availability of professionals to operationalize a standard also influenced hospital’s adoption of a health information technology. It was receommned that, health information technology service providers must make room for the potential clients (like hospitals) to try out the system on a smaller scale, to judge its effectiveness before purchasing it. Hospitals aiming at adopting health information technology should ensure to effectively communicate with their staff on the benefits of the new system, and training them adequately to operate the new systems, as these will help reduce the chance of change resistance.

Source: KNUST