| 1. |
- Armah, Frederick A., et al.
(författare)
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Anthropogenic sources and environmentally relevant concentrations of heavy metals in surface water of a mining district in Ghana: a multivariate statistical approach
- 2010
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Ingår i: Journal of Environmental Science and Health. Part A: Toxic/Hazardous Substances and Environmental Engineering. - : Informa UK Limited. - 1093-4529. ; 45:13, s. 1804-1813
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Tidskriftsartikel (refereegranskat)abstract
- The levels of heavy metals in surface water and their potential origin (natural and anthropogenic) were respectively determined and analysed for the Obuasi mining area in Ghana. Using Hawth's tool an extension in ArcGIS 9.2 software, a total of 48 water sample points in Obuasi and its environs were randomly selected for study. The magnitude of As, Cu, Mn, Fe, Pb, Hg, Zn and Cd in surface water from the sampling sites were measured by flame Atomic Absorption Spectrophotometry (AAS). Water quality parameters including conductivity, pH, total dissolved solids and turbidity were also evaluated. Principal component analysis and cluster analysis, coupled with correlation coefficient analysis, were used to identify possible sources of these heavy metals. Pearson correlation coefficients among total metal concentrations and selected water properties showed a number of strong associations. The results indicate that apart from tap water, surface water in Obuasi has elevated heavy metal concentrations, especially Hg, Pb, As, Cu and Cd, which are above the Ghana Environmental Protection Agency (GEPA) and World Health Organisation (WHO) permissible levels; clearly demonstrating anthropogenic impact. The mean heavy metal concentrations in surface water divided by the corresponding background values of surface water in Obuasi decrease in the order of Cd > Cu > As > Pb > Hg > Zn > Mn > Fe. The results also showed that Cu, Mn, Cd and Fe are largely responsible for the variations in the data, explaining 72% of total variance; while Pb, As and Hg explain only 18.7% of total variance. Three main sources of these heavy metals were identified. As originates from nature (oxidation of sulphide minerals particularly arsenopyrite-FeAsS). Pb derives from water carrying drainage from towns and mine machinery maintenance yards. Cd, Zn, Fe and Mn mainly emanate from industry sources. Hg mainly originates from artisanal small-scale mining. It cannot be said that the difference in concentration of heavy metals might be attributed to difference in proximity to mining-related activities because this is inconsistent with the cluster analysis. Based on cluster analysis SN32, SN42 and SN43 all belong to group one and are spatially similar. But the maximum Cu concentration was found in SN32 while the minimum Cu concentration was found in SN42 and SN43.
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| 2. |
- Armah, Frederick A., et al.
(författare)
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Assessment of legal framework for corporate environmental behaviour and perceptions of residents in mining communities in Ghana
- 2011
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Ingår i: Journal of Environmental Planning and Management. - : Informa UK Limited. - 1360-0559 .- 0964-0568. ; 54:2, s. 193-209
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Tidskriftsartikel (refereegranskat)abstract
- The paper examines the laws and policies that regulate corporate environmental practices in Ghana, with an emphasis on mining. In particular, the analysis of the legal and regulatory framework examines the extent to which it meets international best practices and standards of corporate conduct and the extent to which self-regulatory mechanisms are accommodated under the framework. This was accomplished through reviews of mining and water related Acts, laws and relevant Statutes on corporate environmental practices in Ghana. Ethnographic qualitative research was carried out and key tools utilised included participant observations, focus group discussions and interviews. Interview data captured community members' perceptions on impacts of mining in 12 host communities. Key findings indicate that most respondents have negative perceptions about the socio-economic and environmental impacts of mining and where corporate environmental governance codes exist, enforcement mechanisms are not very well laid out, a situation which reflects weak regulatory institutions in the mining sector. Further, the legal and regulatory regime for environmental governance has failed to come up to international best practices. While government has an important role to play in the area of providing the legal framework for enhancing best practice standards in corporate environmental governance, it appears that the ultimate responsibility for sound environmental behaviour still lies with corporations themselves.
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| 3. |
- Armah, Frederick A., et al.
(författare)
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Impact of Floods on Livelihoods and Vulnerability of Natural Resource Dependent Communities in Northern Ghana
- 2010
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Ingår i: Water. - : MDPI AG. - 2073-4441. ; 2:2, s. 120-139
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Tidskriftsartikel (refereegranskat)abstract
- Sub-Sahara Africa is considered to be most vulnerable to climate variability including flooding. The frequency and severity of floods in Northern Ghana over the last decade has increased considerably. Through qualitative modelling the paper explores the impact of floods on natural resource dependent communities in Northern Ghana. Simplified causal loop diagrams are used to conceptualise flood-induced coping strategies in the study area. The results indicate that some characteristics of the socio-cultural environment appear to mitigate risk and reduce vulnerability. In this context, the role of social networks in enhancing livelihood security is essential. The paper concludes that both in case of seasonal variations in agricultural output and floods, individuals that have effectively diversified their livelihoods, both occupationally and geographically, are less sensitive than individuals who mainly achieve entitlement to food via crop cultivation. However, diversification in this case, is effective only in the short term.
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| 4. |
- Armah, Frederick A., et al.
(författare)
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Management of natural resources in a conflicting environment in Ghana: unmasking a messy policy problem
- 2014
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Ingår i: Journal of Environmental Planning and Management. - : Informa UK Limited. - 1360-0559 .- 0964-0568. ; 57:11, s. 1724-1745
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Tidskriftsartikel (refereegranskat)abstract
- Resource use conflict is an enduring problem for science and policy making. Using in-depth interviews and focus group discussions with resource users, policy makers and key informants, we explored four case examples of resource use conflict within lands and forestry, fisheries, oil and the mining sectors in Ghana. Results indicate that resource use conflict consists of a complex, non-linear system of balancing and reinforcing feedback loops that recur across resource sectors. The conflicts are difficult to clearly define, have many interdependencies and are multi-causal. Specifically, dysfunctional policy, commoditisation of land, infringement on rights of users, shift from communal to private land ownership, renegotiation of rights, and unclear roles and responsibilities of government agencies, exacerbate conflicts among resource users, managers and policy makers in Ghana. In addition, supranational policy such as the protocol of the Economic Community of West African States, which promotes free movement of people and goods within the 16-nation community, is a driver of conflict between native farmers and nomadic Fulani herders. Clear policy directions from government that outlines the specific roles of various departments involved in resource issues together with a holistic community participatory approach is therefore required to comprehensively understand and address such conflicts.
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| 5. |
- Armah, FA, et al.
(författare)
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Food security and climate change in drought-sensitive savanna zones of Ghana
- 2011
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Ingår i: Mitigation and Adaptation Strategies for Global Change. - : Springer Science and Business Media LLC. - 1573-1596 .- 1381-2386. ; 16:3, s. 291-306
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Tidskriftsartikel (refereegranskat)abstract
- Desertification, climate variability and food security are closely linked through drought, land cover changes, and climate and biological feedbacks. In Ghana, only few studies have documented these linkages. To establish this link the study provides historical and predicted climatic changes for two drought sensitive agro-ecological zones in Ghana and further determines how these changes have influenced crop production within the two zones. This objective was attained via Markov chain and Fuzzy modelling. Results from the Markov chain model point to the fact that the Guinea savanna agro-ecological zone has experienced delayed rains from 1960 to 2008 while the Sudan savanna agro-ecological zone had slightly earlier rains for the same period. Results of Fuzzy Modelling indicate that very suitable and moderately suitable croplands for millet and sorghum production are evenly distributed within the two agro-ecological zones. For Ghana to adapt to climate change and thereby achieve food security, it is important to pursue strategies such as expansion of irrigated agricultural areas, improvement of crop water productivity in rain-fed agriculture, crop improvement and specialisation, and improvement in indigenous technology. It is also important to encourage farmers in the Sudan and Guinea Savanna zones to focus on the production of cereals and legumes (e.g. sorghum, millet and soybeans) as the edaphic and climatic factors favour these crops and will give the farmers a competitive advantage. It may be necessary to consider the development of the study area as the main production and supply source of selected cereals and legumes for the entire country in order to free lands in other regions for the production of crops highly suitable for those regions on the basis of their edaphic and climatic conditions.
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| 6. |
- Armah, FA, et al.
(författare)
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Mapping of noise risk zones derived from religious activities and perceptions in residential neighbourhoods in the Cape Coast metropolis, Ghana
- 2010
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Ingår i: Environmental Hazards: Human and Policy Dimensions. - : Informa UK Limited. - 1747-7891. ; 9:4, s. 358-368
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Tidskriftsartikel (refereegranskat)abstract
- Ambient noise levels emanating from religious activities in residential neighbourhoods are an emerging environmental problem that educes little attention from enforcement agencies and policy makers in Ghana. This paper set out to quantify religious noise exposure in urban residential neighbourhoods in the Cape Coast metropolis of Ghana. Subjective annoyance levels of residents in selected communities were determined. Noise risk zones were mapped using ARCGIS 9.3 software and surface interpolation for the data was carried out using inverse distance weighting. The results show that most (77 and 86 per cent) of the locations recorded noise levels that were above the Ghana Environmental Protection Agency maximum permissible limit for day and night, respectively. Pearson's correlation coefficient for day and night noise exposure shows strong association (0.714) at the 0.01 level. There is variability in the levels of noise for both day and night, which are rather high (standard deviation = 7.59477 and 7.94022, respectively). Generally, levels of noise exposure correlated with levels of annoyance of residents, except that the highest noise exposure was not recorded in the community where the annoyance level of residents was highest. Residential neighbourhoods within the study area largely experienced safe to tolerable levels of religious noise, although 5 per cent were within the high-risk zone. Given that the selected residential areas have high population densities, even when the dispersion of noise risk is spatially limited, it affects a large number of people who belong to different socio-economic classes.
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| 7. |
- Tambang, Yengoh Genesis, et al.
(författare)
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Agro-climatic resources and challenges to food production in Cameroon
- 2011
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Ingår i: Geocarto International. - : Informa UK Limited. - 1010-6049 .- 1752-0762. ; 26:4, s. 251-273
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Tidskriftsartikel (refereegranskat)abstract
- The agro-climatic resources of Cameroon are examined in light of the potential for food crop production and challenges presented by climate change. We find that the diversity of Cameroon's agro-climate offers the potential for the cultivation of a variety of food crops. This feature of Cameroonian agriculture can be used in addressing the country's adaptive capacity to climate change. However, the Savanna zones of the country, which are its most productive, are also the most vulnerable to climate change. The main climate change challenge in these Savanna zones is that of drought and associated agricultural water demand. Appropriate management strategies to address agricultural water demand can also address important problems in Cameroonian agriculture, such as the effects of climatic uncertainties in small-scale food crop production and soil nutrient depletion. To ensure the success of these management strategies, a number of obstacles may have to be addressed.
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| 8. |
- Tambang, Yengoh Genesis
(författare)
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Climate and Food Production: Understanding Vulnerability from Past Trends in Africa's Sudan-Sahel
- 2013
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Ingår i: Sustainability. - : MDPI AG. - 2071-1050. ; 5:1, s. 52-71
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Tidskriftsartikel (refereegranskat)abstract
- Just how influential is rainfall on agricultural production in the Sudan-Sahel of Africa? And, is there evidence that support for small-scale farming can reduce the vulnerability of crop yields to rainfall in these sensitive agro-ecological zones? These questions are explored based on a case study from Cameroon's Sudan-Sahel region. Climate data for 20 years and crop production data for six major food crops for the same years are used to find patterns of correlation over this time period. Results show a distinction of three periods of climatic influence of agriculture: one period before 1989, another between 1990 and 1999 and the last from 2000 to 2004. The analysis reveals that, while important in setting the enabling biophysical environment for food crop cultivation, the influence of rainfall in agriculture can be diluted by proactive policies that support food production. Proactive policies also reduce the impact of agriculturally relevant climatic shocks, such as droughts on food crop yields over the time-series. These findings emphasize the extent of vulnerability of food crop production to rainfall variations among small-holder farmers in these agro-ecological zones and reinforce the call for the proactive engagement of relevant institutions and support services in assisting the efforts of small-scale food producers in Africa's Sudan-Sahel. The implications of climate variability on agriculture are discussed within the context of food security with particular reference to Africa's Sudan-Sahel.
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| 9. |
- Tambang, Yengoh Genesis, et al.
(författare)
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Crop Yield Gaps in Cameroon
- 2014
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Ingår i: Ambio: a Journal of Human Environment. - : Springer Science and Business Media LLC. - 0044-7447. ; 43:2, s. 175-190
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Tidskriftsartikel (refereegranskat)abstract
- Although food crop yields per hectare have generally been increasing in Cameroon since 1961, the food price crisis of 2008 and the ensuing social unrest and fatalities raised concerns about the country's ability to meet the food needs of its population. This study examines the country's potential for increasing crop yields and food production to meet this food security challenge. Fuzzy set theory is used to develop a biophysical spatial suitability model for different crops, which in turn is employed to ascertain whether crop production is carried out in biophysically suited areas. We use linear regression to examine the trend of yield development over the last half century. On the basis of yield data from experimental stations and farmers' fields we assess the yield gap for major food crops. We find that yields have generally been increasing over the last half century and that agricultural policies can have significant effects on them. To a large extent, food crops are cultivated in areas that are biophysically suited for their cultivation, meaning that the yield gap is not a problem of biophysical suitability. Notwithstanding, there are significantly large yield gaps between actual yields on farmers' farms and maximum attainable yields from research stations. We conclude that agronomy and policies are likely to be the reasons for these large yield gaps. A key challenge to be addressed in closing the yield gaps is that of replenishing and properly managing soil nutrients.
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| 10. |
- Tambang, Yengoh Genesis
(författare)
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Explaining Agricultural Yield Gaps in Cameroon
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Popular Abstract in Swedish Ökad livsmedelsproduktion utgör ett viktigt steg för att uppnå livsmedelssäkerhet i Kamerun. Under det senaste halvseklet har ökningen av produktionen i huvudsak uppnåtts genom ökad uppodling. Till följd av ökad konkurrens om marken från jordbruket och andra sektorer är dessa möjligheter till ökad produktion, för att möta landets växande efterfråga nu begränsad. Alternativet är att öka avkastningen på den mark som redan odlas. Frågan som ställs i denna avhandling är därför hur mycket avkastningen kan öka? Dessutom är det nödvändigt att förstå vad de huvudsakliga hindren är för att minska klyftan mellan verklig och potentiell avkastning. I avhandlingen används en kombination av kvantitativa och kvalitativa metoder för att utforska dessa frågor. Resultaten visar att det finns stora skillnader mellan existerande och potentiell avkastning på viktiga livsmedelsgrödor i Kamerun. Skillnaderna beror främst på agronomiska snarare än biofysiska faktorer. Resultaten visar även att småskaliga jordbrukare har god kunskap om orsakerna till både avkastningsgapen och den låga jordbruksproduktionen i allmänhet. De småskaliga jordbrukarna är utsatta för chocker som översvämningar och torka. Rätt institutionellt och strukturellt stöd skulle kunna lindra konsekvenserna av dessa för livsmedelsproduktionen och avkastningen. En viktig förutsättning för att minska avkastningsgapet är bättre växtnäringsplanering för att återställa jordarnas sjunkande produktivitet. Med tanke på nuvarande socio-ekonomiska och miljömässiga förhållanden, kan det ökande beroendet av oorganisk gödning inte anses vara en lämplig strategi. En hållbar intensifiering med betoning på ekologiskt jordbruk erbjuder betydande fördelar i att överbrygga avkastningsgapet. Statligt stöd är en förutsättning för att att genomföra och upprätthålla ett sådant jordbrukssystem. Det finns också behov av att förändra den socio-ekonomiska kontexten för småskaliga jordbruksmetoder där könsrelaterade skillnader i tillgång till produktionsresurser minskas, och där jordbrukare ingår som viktiga intressenter i de beslutsprocesser som berör jordbruket.
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