Assessing the Impact of Climate and Change and Variability on Irish Potato (Solanum Tuberosum L. ) Production from 1995 to 2015 in Tubah Sub Division, North West Region, Cameroon

Climate change and variability are common phenomena that affect crop productivity globally but with significant differences between different regions of the world. Studies of the impacts of these phenomena on Irish potato –Solanum tuberosum L.-production within Tubah Sub-Division based on records of precipitation and temperatures from 1995 to 2015, indicated an increasing mean annual temperature rate of 0.09 0C per year and a slight  increasing annual rainfall rate of 25.8 mm per year. Potato yields within the same period equally increased by 1.26 t/ha per year until 2012 when the yields started decreasing due to a correspondingly marked  increase in both temperature and rainfall. The drop in potato yields has also been attributed to disease infestation such as potato blight and rot which are favoured by the increases in temperature and rainfall. Statistical correlation and regression analyses of these data revealed that the potato yields showed weak positive correlations with temperature (R= 0.02) and with rainfall (R= 0.12). Results from questionnaire survey, focus group discussions and semistructured interviews indicated that the potato crop (63 %) of most farmers were negatively affected by climate change and  variability through the increased sporadic rainfall which enhanced potato blight and rot. Some adaptation strategies to these climatic factors are already being practised by most farmers (81 %) who are making use of a combination of fertilizers, pesticides, improved seeds and irrigation  practices to remedy the situation although further approaches such as the use of resistant species are necessary towards improving on the dwindling potato yields.Keywords: Climate, Change, Variability, Tubah Sub Division, Irish Potato, Adaptation Strategies, Cameroon

The utilisation of satellite imagery and community perceptions to assess the impacts of sea encroachment in the West Coast of Cameroon at Limbe

Coastal erosion associated to sea encroachment is a major problem at the West Coast of Limbe, specifically in the Debundscha Fishing Port (DFP). This study sought to assess the physical vulnerability of the West Coast of Limbe to coastal erosion associated to sea encroachment. This was achieved by assessing: i) the physical vulnerability of the West Coast to coastal erosion; ii) land cover changes and iii) community perception at DFP to sea encroachment and coastal erosion in the past 30 years. Three variables: rock type, adjacent land use and coastal protection were used to assess the vulnerability of the West Coast to coastal erosion. Landcover / coastal changes were assessed from satellite images from 1986 to 2018. Semi-structural interviews were used to acquire knowledge on the population’s perception and impact of the studied hazards. A cost benefit approach was used to weigh the potentials of these localities to adapt to coastal erosion. The DFP and Idenau Beach were identified as major hotspots of coastal erosion with an annual rate of >100 m².  Landcover changes showed a net increase in water levels inland and into settlements. The population is knowledgeable and is aware of the risk of sea encroachment and coastal erosion. The physical, socio-economic and health effects were: destruction of mangroves;relocation; malaria, typhoid and abdominal illnesses respectively. Coping strategies included the use of sandbags, building on higher grounds and on embankments. Cost benefit analysis ranked vegetative cover as the best option environmentally and financially viable to reduce coastal erosion from sea encroachment at the West Coast. Key words: Sea encroachment, coastal erosion, physical vulnerability, perception, Debundscha Fishing Por

Impacts of Climate Change and Climate Variability on Cocoa (Theobroma Cacao) Yields in Meme Division, South West Region of Cameroon

An assessment of trends of climate change and variability on cocoa yields from 1975 to 2010 in Meme Division aimed at providing a framework for future adaptation strategies was focused on relating cocoa yield with climatic conditions. Rainfall and temperature data were analyzed by fitting regression lines in an attempt to determine their trend during the study period and possible future projections. The purposive sampling technique was used to select ten villages using a criteria based on the proportion of the population involved in cocoa cultivation. Farm selection was based on age, consistency of sizes and management practices in an attempt to keep the factors affecting cocoa yield constant. Data on cocoa yield, flowering, and pod infestation were obtained through semi-structured questionnaire and analyzed using univariate, bivariate and graphical techniques. The results revealed that increased rainfall above 3000mm per annum, decreased cocoa yields by 0.16% per millimeter while increased temperatures of 0.34°C per decade increased cocoa yield. Flowering intensity also varied with seasons and was continuous in some localities, while cocoa black pod infestation increased with rainfall and low temperatures, and vice versa for capsids.Keywords: climate change and variability, cocoa yields, Meme Division, black pod infestation, capsidsJOURNAL OF THE CAMEROON ACADEMY OF SCIENCES VOL. 11 No. 1 (2013

A regional and seismic stratigraphic interpretation in the Danish North Sea

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An assessment of the potability of some sachet water brands sold in Cameroon

Analysis of the microbial and physico-chemical qualities of 14 sachet water brands sold in Cameroon was carried out aimed at determining their potability based on World Health Organization (WHO)  recommendations. Similar analyses of water samples from the respective sources were used to compare the quality of the water at source and in the sachets in an attempt to identify potential sources of  contaminants in each sachet where appropriate. The most probable number  method was used to   determine the total coliforms in the water while eosine methylene blue (EMB) agar was used for the  detection of faecal coliforms and to differentiate Escherichia coli from other gram-negative pathogens  present in the water samples that showed the presence of coliforms. The physical parameters  examined were pH, electrical conductivity (EC), and the total dissolved solids (TDS) using a ++WTW 315i pH meter and a Cond 330i/set, while total suspended  solids (TSS) were determined by filtration, and alkalinity  determined by titration using hydrochloric acid. The following major ions were determined using ion  chromatography: Na+, K+, Mg2+, Ca2+, F-, Cl-, NO3 -, PO43-, SO4 2-and HCO3 -. The results   indicated  that the pH, TSS, EC, TDS fell within the WHO limits for potable water. The main water types were Ca-Mg-HCO3, Na-KSO 4-Cl and Na-K-HCO3 with 50% of the samples clustered in the Ca-Mg-HCO3 zone and the rest in the Na-K-SO4-Cl (30%) and in the Na-K-HCO3 (20%) zones. The major ions in all water samples were Na+, K+, Mg2+, Ca2+, Cl- and HCO3 - and their presence was shown to be primarily attributable to the natural geological conditions of the water sources. Although results of the physico-chemical analyses were indicative of acceptable limits for potability, the results of microbial analysis indicated that about 85 % of the brands tested were microbially unsuitable for consumption. The health implications of these results call for further assessment of the policy and management of the sachet water industry in the country.Key words: sachet water, potability, physico-chemical, microbial, quality