ghanaopendata/ghanaian-research-english huggingface dataset:
Estimating the Spatial Distribution of Monthly Mean Global Solar Radiation Over Ghana Using the A˙ ngström􀀀Prescott Model

Quantifying the amount of Global Solar Radiation (GSR) reaching the surface of the earth over a specified area is essential for both energy technologies such as solar heating, solar photovoltaics, solar thermal energy, and solar architecture and climate impact studies. In this study, the A˙ ngström􀀀Prescott sunshine duration model is used to estimate monthly mean GSR over Ghana from sunshine duration data measured at twenty synoptic stations distributed across the country. The measured sunshine duration datasets for the model was obtained from the Ghana Meteorological Agency (GMet), distributed over the four agro-ecological zones and spanning a 3-year period (2000 – 2002). The estimated monthly mean GSR datasets were then gridded at a spatial resolution of 10 km 10 km, establishing the trend and distribution of Global Solar Radiation across the country. The gridded dataset was then compared with satellite data from the National Renewable Energy Laboratory (NREL) and the German Aerospace Centre (DLR) at a spatial resolution of 10 km 10 km. The results produced appreciable root mean square error values of 1-5, relative mean difference values of 0.03-0.22, absolute mean percent error of 3-29, and correlation coefficient values between 57.8% and 66%. In addition, the estimated total monthly mean Global Solar Radiation over the country is 412.82 MJm􀀀2day􀀀1 equivalent to 4778.02 Wm􀀀2. The savanna zone has the maximum estimated monthly mean GSR, with the highest level estimated at Navrongo (20.76 MJm􀀀2day􀀀1) equivalent to 240.28 Wm􀀀2, showing only 0:32% increment over the study period. The forest zone has the minimum estimated monthly mean GSR, with the lowest radiation level estimated at Oda (17.11 MJm􀀀2day􀀀1) equivalent to 198.03 Wm􀀀2. A maximum and minimum mean clearness index of 0:59 and 0:48 respectively is estimated. This means an estimated 53% of Solar radiation at the top of the atmosphere reaches the study area after attenuation. Meanwhile, the maximum annual time series GSR over the country is within the second trimester of the year (March-April-May), and the minimum annual time series GSR are within the wet and harmattan periods of the year. The satellite data has a total monthly mean Global Solar Radiation of 366.62 MJm􀀀2day􀀀1 equivalent to 4243.30 Wm􀀀2. The study shows that solar radiation levels over the country (17.11 MJm􀀀2day􀀀1 to 20.76 MJm􀀀2day􀀀1), meet the international solar technology market standards of 18.7 MJm􀀀2day􀀀1 to 20.7 MJm􀀀2day􀀀1 for the operation of photovoltaic systems and solar collectors for industrial and domestic applications.

Source: KNUST
Estimation and mapping of carbon stocks in Bosomkese Forest Reserve, Ghana

Biomass estimation has become a critical element in global environmental studies, because the change in biomass is deemed as an important component of climate change. The aim of this research is to estimate and map carbon stocks in Bosomkese forest reserve using remote sensing, GIS applications and field measurement method. Out of the six carbon pools of terrestrial ecosystem, carbon sequestration of three (above ground, below ground and deadwood) were assessed. Advanced Land Observing Satellite (ALOS) image acquired in 2010 was classified using Erdas Imagine. Total of five land use/land cover classes were identified; Closed canopy natural forest, open canopy natural forest, plantation, farmland and fallow land. Diameter at breast height and total height of standing trees as well as the end diameters and the length of downed deadwood were measured in fifty sample plots in the five land use classes. These measurements were converted into above ground carbon (AGC), below ground carbon (BGC) and deadwood carbon (DWC) using allometric equations. Total carbon for each plot was the summation of AGC, BGC and DWC. This research showed that closed canopy natural forest (1748.37 ton/Ha) contained more carbon than the rest of the land use/cover classes. This was followed by open canopy natural forest (1164.12 ton/Ha), plantation (775 ton/Ha), fallow land (110.69 ton/Ha) and farmland (45.13 ton/Ha) in descending order of total carbon stocks. The carbon / carbon dioxide equivalent value together with the plots coordinates were used to generate carbon stock and carbon dioxide equivalent map using Geostatistics tool of ArcGIS 10.0. The total carbon stock for the whole Bosomkese forest is in the range of 2,236,938.90 – 2,865,148.33 tons and carbon dioxide equivalent in the range of 8,534,225.45 – 10,507,952.05 tons. This research has given an estimated carbon stock in Bosomkese forest reserve which can be used as baseline carbon information. With continuous biomass estimation at ten years interval, change in biomass can be determined which will help decision makers in their planning on climate change in Bosomkese, its environment and the country as a whole.

Source: KNUST
Estimation of borehole yield using vertical electrical sounding data: a case study from Kwabre District

Groundwater has been identified as the world’s largest resource that can be easily accessed especially when confronted with water shortages as a result of low river discharges. Successful execution of groundwater exploration using geophysical methods requires knowledge on the relationships that exist between hydrogeological and geophysical parameters. This makes data interpretation and delineation of groundwater zones easier, thereby avoiding the drilling of marginal holes. This study was carried out in the Kwabre District and was aimed at establishing a relationship between airlift yields and electrical resistivity parameters. Three methods, viz. borehole log analysis, cumulative resistivity method and the drilling rate with respect to formation analysis, were employed to obtain resistivity (rho) and thickness of the saturated zones from borehole logging and vertical electrical sounding data. The obtained resistivity and saturated thickness were used to compute transverse resistance (Tr) and longitudinal conductance (Sc). Each of these parameters (i.e. Tr and Sc) including the resistivities of the saturated zones were further correlated with airlift yields of the boreholes to evaluate their relationships. Also, the airlift yields were used to create a yield map of the district. Correlation results obtained from the borehole log analysis and cumulative resistivity method suggest there is no relationship between the airlift yield and the resistivity parameters. On the other hand, results obtained from the drilling rate with respect to formation analysis showed that the yield versus resistivity, longitudinal conductance and transverse resistance are related by 60.85%, 57.16% and 50.25% respectively. However, validations of the associated models were very poor in predicting measured airlift yield values. Thus, further studies may be required to improve and validate the method. This study also provided useful information on the variation of airlift yields in the district.

Source: KNUST
Estimation of genetic improvement of maize in Ghana under three levels of nitrogen application

The Crop Research Institute of Ghana has released quality protein maize and hybrids into the Ghanaian market for full utilization by farmers and researchers to enhance food security in the country. The research was conducted to estimate the genetic improvement of maize in Ghana under three levels of nitrogen fertilizer application. The experiment was conducted in the 2011 major and minor seasons at Kwadaso and Fumesua. The genotypes comprised of 3 hybrids, 6 open- pollinated varieties (OPV’s), 1 local variety and 4 inbred lines released from 1955 to 2010. The experimental design used was 3 × 14 factorial in a randomized complete block design in split-plot arrangement, with four replications in each environment. The nitrogen levels were 0, 45 and 90 kg N /ha randomized in the main plot and genotypes as the sub-plots. The analysis of variance showed that the effects due to environments, nitrogen levels, and genotypes were highly significant (P<0.01) for grain yield and other agronomic traits measured. The differences among genotypes were highly significant (P< 0.01) for grain yield and other agronomic traits. Genotype X Environment interactions were highly significant (p < 0.01) for grain yield, days to mid-silks, days to mid- anthesis, plant height, ear height, lodging, rust, blight, cob aspect, shelling percentage, 1000 seed weight and cob length. The response to nitrogen in terms of the genotypes ascertain that the hybrids out yielded the open- pollinated varieties and local variety at 0, 45, 90 kg N/ha respectively. Yields of hybrids responded positively over OPV’s with an increased with nitrogen levels from 0 kg N/ha to 45 kg N/ha. Hybrids were also the most stable and highest yielding varieties under high nitrogen environments. It is recommended that farmers should be encouraged to buy and use hybrid seed to take advantage of their high yields under low N.

Source: KNUST
Estimating the transaction cost indices of public private partnership infrastructure in Ghana (Case study of Kumasi Metropolitan Assembly)

Public Private Partnership infrastructure projects have existed in the field of procurement for some time now however, it implementation in Ghana is at its early stages implying that transaction cost estimation of PPP projects are yet to be explored. The study focused on estimating Transaction Cost Indices for PPP projects undertaken in the Kumasi Metropolitan Assembly which happens to be the first of its kind in the Ashanti Region. Two supporting objectives were set to address the aim of the study, they are: firstly, identify areas that substantially contribute to transaction cost of PPP projects and secondly, estimation of transaction cost indices of PPP infrastructure projects. The study relied on data from the works department of the Kumasi Metropolitan Assembly on PPP projects concurrently on-going in four of their Sub Metropolitan Assemblies namely Subin, Tafo, Bantama and Kwadaso. They are five (5) projects in all, with most of them being shopping facilities and complexity of the projects varies. Feasibility studies cost tend to be the cost area that substantially contribute higher quota to the Transaction cost of PPP projects in the KMA. Furthermore, the study was able to come out with cost index for all the five (5) projects studied, therefore future projects can rely on the cost index as a guide on transaction cost expenses. Finally, transaction cost threshold was estimated in order to provide a ceiling of estimating the transaction cost index for projects. Therefore, it is recommended that, though private investors pay for the actual cost of the projects MMDAs can also reduce the transaction costs which are incurred during the initial stages of the project. It is recommended that further studies will consider all the Metropolitan, Municipal and District Assembly separately to come out with a transaction cost indices for the respective types of Assemblies.

Source: KNUST
Estimation and Fitting Rainfall Pattern Distribution in Ghana using the Expectation-Maximization Algorithm with some Probability Models

The study investigated the rainfall pattern estimation involving fteen selected rainfall stations across Ghana for the period of sixteen years (2000-2015) with the main objective of estimating the missing values and determining the annual average rainfall values for the period under study. The observed data was tted with three probability distributions which were; Gamma, Lognormal and Normal. Goodness-of- t tests were conducted in order to select the best model t. These included Kolgmorov-Smirnov, Cramer-von Mises and Anderson-Darling tests to- gether with the Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC). The normal probability distribution was selected as the best model since it provided the minimum goodness-of- t test statistic values. The EM algorithm which has the capability to deal with missing values was used to complete the missing data and together with the normal distribution, esti- mated the average rainfall values of the various stations. The estimates of the EM algorithm were observed to be better estimates for the data because they were smaller than the regular estimates and also provided the least log-likelihood values. Therefore, we recommend that the Expectation-Maximization algorithm (Normal EM algorithm) should be used to estimate the missing values as well as the annual average rainfall of the daily rainfall data recorded in Ghana.

Source: KNUST
Estimation of NERICA adoption Rates and Impact on Productivity and Poverty of the Small-Scale Rice Farmers in The Gambia

dy uses a country-wide data from a stratified sample of 600 rice farmers to assess NERICA adoption rates and the causal effect of NERICA adoption on rice yields and income. It reveals that the observed sample adoption rate does not consistently estimate the true population adoption rate even if the sample is randomly selected. Consequently, it uses the counterfactual outcomes framework to estimate the true population adoption rate which corresponds to what is defined in the modern policy evaluation literature as the average treatment effect (ATE). The ATE estimate shows that the NERICA adoption rate could have been 83% instead of the observed 40% sample estimate provided exposure to NERICA was complete in 2006 or before. This shows an adoption gap of 43%, which represents a very high unmet demand for NERICA in The Gambia. Moreover, the results of the causal effects of NERICA adoption on rice yields and income based on observed sample estimates show significant differences between NERICA adopters and non-adopters. However, since the observed estimates could be attributed to differences in socio-demographic and environmental characteristics of adopters and non-adopters, they may not have any causal interpretation of NERICA adoption on the variables of interest. Indeed, the importance of some socio-demographic and environmental characteristics variable in explaining the differences in rice yields and income between NERICA adopters and non-adopters was confirmed by the data analysis. Hence, the study uses the counterfactual outcome framework to control for such differences. The results of the framework based on ATE estimates show in general significant estimates of NERICA adoption on rice yields and income. However, since adoption is a choice variable, the ATE estimates cannot be given a causal interpretation. Therefore, the study proceeds with the LATE estimates, the impact parameter which has a causal interpretation under this circumstance. The LATE estimates show that NERICA adoption significantly increases average rice yields and daily income of small-scale rice farmers by 146 kg/ha and D10.16 respectively.

Source: KNUST
Estimation of economic cost of forest fire prevention and control

Bush fires in general, and forest fires in particular, have become a thorny issue in Ghana since the wide spread bush fires of 1983. They have reduced the productive capacity of timber and non-timber forest products. They have also affected the biodiversity and the ecological balance. Efforts have been made to rescue the situation and cost has been incurred by both governmental and non-governmental fire management inputs. The problem is that there has not been economic analysis about the cost effectiveness of the efforts. This is attributed to the problem of estimating economic cost of fire management in Ghana. The main objective of the study was to estimate economic cost of fire management programmes incurred by fire management input units engaged in fire prevention and control. The study used a modified version of cost aggregation model derived by McKetta et al for the estimation. In the estimation the study identified four management input units; Ghana National Fire Service, Anti-Bush Fire Volunteers, Forestry Department and Green Belt Farmers. The study applied the model in four forest reserves; namely Pamu Berekum, Tam Block II, Afram Headwaters, and Worobong South forest reserves. The study employed questionnaire in the data collection. Four sets of questionnaires were administered on the four fire management inputs. The study was also supplemented by interviews and information from libraries and other institutions. The estimation was followed by comparative analysis of cost from the fire management inputs, between and within the four forest reserves and also between fire management programmes. Furthermore, the study conducted statistical analyses to test the consistency in the cost estimates from fire management inputs on different management programmes in the forest reserves. The main findings of the study were that; the non-governmental fire management inputs were more actively involved in fire management and the governmental fire management inputs only pay lip service to fire management; fire volunteers were the only fire management input which was involved in suppression programme; the greater part of the cost of non-governmental fire management input were imputed labour wages; some fire management inputs were concerned about only some specific programmes; the fire management inputs in general concentrated on only few fire management programmes; total economic cost was highest in Pamu Berekum and lowest in Tam Block 11; and it was observed that forest type and location had no influence on cost estimates. The study was organised into five chapters. Chapter one covered introduction and chapter two covered literatures review. Chapter three, four and five covered; model of the study, presentation and analysis, and summary and conclusion, respectively.

Source: KNUST
Estimation of petrophysical data for assessing hydrocarbon potential in Western Ghana Oilfield (Tano Basin)

Well log data were obtained from Ghana National Petroleum Corporation for each of the six exploratory wells studied. For each well, the following logs were collected; resistivity log, sonic log, formation density compensated log, compensated neutron log and gamma ray log. These in situ well logs were subjected to well log analysis and interpretation methods. The following Petrophysical parameters; porosity, permeability, water saturation, reservoir thickness and volume of shale were estimated for each hydrocarbon-bearing zone delineated for each well. The data obtained have been analyzed and interpreted quantitatively, to assess the hydrocarbon potential of each well. The mean estimates for porosity and permeability of all the oil-bearing zones delineated, range from 23.75 % to 34 % for porosity and 65 md to 714.7 md for permeability, compared to mean porosity range of 8.5 – 23.15 % and permeability range of 6.83 × 10-2 md to 5.99 md of the gas zones. The results of the well logs interpretation suggest that oil- bearing zones are much more porous and permeable than the gas-bearing zones. This was evident throughout the wells. The estimates for the water saturation of hydrocarbon-bearing zones range from 6 % to 63.6 % indicating good hydrocarbon saturation potential. The reservoir thickness estimated for all the oil-bearing zones delineated range from 2 m to 40 m while the gas-bearing zones range from 4 m to 10 m. The Western Basin low estimated reservoir thicknesses for hydrocarbon-bearing zone suggests that reservoir reserves potentials are not sufficient, but the range 8 % to 36.8 % of volume of shale estimated for the hydrocarbon-bearing zones of the wells suggests that sandstone lithology of the Western Basin is clean. The Western Basin proved to be a high capital venture, as far as drilling is concern due to abnormal high pressure zones detected in almost all the wells studied.

Source: KNUST
Estimation of Margins and Efficiency in the Ghanaian Yam Marketing Chain

The main objective of the paper was to examine the costs, returns and efficiency levels obtained by key players in the Ghanaian yam marketing chain. A total of 320 players/actors (farmers, wholesalers, retailers and cross-border traders) in the Ghanaian yam industry were selected from four districts (Techiman, Atebubu, Ejura-Sekyedumasi and Nkwanta) through a multi-stage sampling approach for the study. In addition to descriptive statistics, gross margin, net margin and marketing efficiency analyses were performed using the field data. There was a long chain of greater than three channels through which yams moved from the producer to the final consumer. Yam marketing was found to be a profitable venture for all the key players in the yam marketing chain. Net marketing margin of about GH¢15.52 (US$9.13) was obtained when the farmer himself sold 100tubers of yams in the market rather than at the farm gate. The net marketing margin obtained by wholesalers was estimated at GH¢27.39 per 100tubers of yam sold, which was equivalent to about 61% of the gross margin obtained. Net marketing margin for retailers was estimated at GH¢15.37, representing 61% of the gross margin obtained. A net marketing margin of GH¢33.91 was obtained for every 100tubers of yam transported across Ghana’s borders by cross-border traders. Generally, the study found out that net marketing margin was highest for cross-border yam traders, followed by wholesalers. Yam marketing activities among retailers, wholesalers and cross border traders were found to be highly efficient with efficiency ratios in excess of 100%. However, yam marketing among producer-sellers was found to be inefficient with efficiency ratio of about 86%.The study recommended policies and strategies to be adopted by central and local government authorities to address key constraints such as poor road network, limited financial resources, poor storage facilities and high cost of transportation that serve as impediments to the efficiency of the yam marketing system in Ghana.

Source: KNUST