Open Access Original Research Article

Mapping Perennial Crops in Africa: A Case Study of Oil Palm in Ghana

Njomaba Elisha, James Nana Ofori, Ben Emunah Aikins, Gideon Adzraku

Journal of Geography, Environment and Earth Science International, Page 1-20
DOI: 10.9734/jgeesi/2021/v25i530283

Forests in Sub-Saharan Africa are experiencing some of the highest rates of deforestation and degradation in the world, with most natural forest species being replaced by cropland and plantation monoculture. In this work, a method was developed that combined the Synthetic Aperture Radar (Sentinel-1) and optical satellite imagery (Sentinel-2) data to accurately map natural forest and perennial crops (oil palm) in Ghana. This was done using all three variables including spatial, spectral, and temporal variables to assess the most important variables in characterizing oil palm and natural forest, as well as the added value of sentinel-1 SAR data in a sentinel-2 optical-based classification. In this workflow, the Gray level co-occurrence matrix (GLCM) was calculated as representing textural/spatial variables, a yearly median composite to represent the spectral variables, and raining and dry season composites of Normalized Difference Vegetation Index  (NDVI) and Normalized Difference Moisture Index (NDMI) to represent the temporal variables for the Sentinel-2 data. In terms of the SAR data, rainy and dry season composites of NDVI and NDMI were calculated. With all these variables together, a characterization of the study area was conducted based on reference data of the land use land cover classes including oil palm, natural forests, and croplands (others) using Random Forest classifier. The variable importance of the Random Forest model was investigated to identify the top 10 most important variables. Results from this study showed that spectral variables followed by spatial variables are the most important and need to be considered when characterizing oil palm and natural forest, which is consistent with some pieces of literature. The use of sentinel-2 data achieved an acceptable classification accuracy (75%); whereas, sentinel-1 SAR further increased the accuracy (up to 85%) as compared to sentinel-2 only.

Open Access Original Research Article

Persistent Challenges of Potable Water Supply, Implications and Mitigation Strategies in Limbe, Cameroon

Emmanuel Nong Buh, Amos Fang Zeh, Ukah Bonaventure Ngong

Journal of Geography, Environment and Earth Science International, Page 21-29
DOI: 10.9734/jgeesi/2021/v25i530285

Persistent challenges of potable water supply and its implications hinder man’s progress in Limbe municipality. The growing population of Limbe Municipality faces increasing challenges of potable water supply with lots of implications. And the Cameroon Water Utilities Corporation (CAMWATER) with the local communities involved in potable water management is unable to meet up with this increasing demand.  This has led to the challenges of potable water supply in Limbe municipality which is very frustrating to water consumers. This present study sought to examine the challenges of potable water supply and its implications in Limbe. A combination of research methods (desk review, interviews and reconnaissance field appraisal) have been used in this study. Our findings revealed that increasing population and poor management of potable water supply were the major problems. In the methods utilized, a community based cross-sectional survey was conducted from March to December 2020 using quantitative and qualitative approaches. Wealth Health Organization checklist was used for observation around catchments, then the assessment of water supply challenges was done with a semi quantitative approach. And 200 questionnaires were administered where qualitative data was collected through Focus Group Discussions and in-depth interviews. The results obtained from the 7 water catchments assessed indicated that 50% of the water supply challenges were as a result of the increasing population in Limbe municipality. Meanwhile 30% stated that poor management of potable water supply by the authorities concern is another reason of persistent challenges of potable water supply in Limbe. While 20% were of the opinion that the challenges of potable water supply is as a result of anthropogenic activities near water catchments leading to a progressive reduction in water volume. An integrated potable water management team is needed and a periodic monitoring of these catchment in order to reduce this persistent challenges.

Open Access Original Research Article

GIS-Based Emergency Fire Response for Minimization of Fire Outbreaks in the Greater Accra Metropolis, Ghana

Emmanuel Yeboah, Isaac Sarfo, Edward Kweku Nunoo, Vanessa Kudoh, Nii Shang, Foster Kofi Addai, Solomon Obiri Yeboah Amankwah, Emmanuel Adu Gyamfi Kedjanyi

Journal of Geography, Environment and Earth Science International, Page 30-45
DOI: 10.9734/jgeesi/2021/v25i530286

The study report assessed the geographic distribution of existing fire stations in the Accra Metropolitan Area (AMA). It further sought to evaluate the spatial coverage for each fire station under predefined sustainable response times. Information on fire stations and incidents, access to sources of water and settlements were purposively obtained and visualized in Arc Map 10.6 with the multiple buffer tools. GIS web application was developed to integrate reporters and fire stations within the AMA for an efficient and effective response to emergency cases related to fire outbreaks. Results suggest that GIS application is essential to fire management as it significantly improved response time to 15 minutes, reducing causalities as well as damaged properties if the strategy is adopted.  Results proved a response time of 15 minutes is feasible in the study area if the proposed strategy is adopted. The study presents this management system as one that could be easily be deployed to other stations across the country. The platform provides details on the location, the magnitude of the fire incident among other relevant details. This study would regulate and minimize risks associated with fire outbreaks which are often accompanied by both direct and indirect consequences and could facilitate early reporting using mobile collection devices.

Open Access Original Research Article

Geoelectrical and Physicochemical Evaluation of Soil Corrosivity on Metallic Pipelines: A Case Study

Ismaila Abiodun Akinlabi, Moshood Lekan Olaiya

Journal of Geography, Environment and Earth Science International, Page 46-56
DOI: 10.9734/jgeesi/2021/v25i530287

Geoelectrical sounding and physicochemical analyses were conducted on the topsoil underlying Osupa area in Ogbomoso, south western Nigeria to evaluate the soil corrosivity on the metallic water pipelines across the area. Schlumberger electrical resistivity soundings were conducted at 24 stations with electrode spacing varied from 1 to 100 m. The resistivity data were interpreted by using partial curve matching and computer-aided 1D inversion. Physicochemical analyses were also conducted on soil samples collected from about 1 m depth in test pits dug at points coincident with the sounding stations, following the BS/AWWA/ANSI Standards for Corrosivity testing to determine the soil pH, redox potential, moisture content and chloride content. The soil corrosivity was evaluated based on soil resistivity alone and the combined effect of soil pH and resistivity. The studied soils have resistivity ranging from 10 Ωm to 492 Ωm and thickness varying from 0.5 m to 4.6 m. The pH, moisture content, redox potential and chloride content range from 4.22 to 8.41, 14.33% to 29.09%, +50 mV to +97 mV and 102 ppm to 196 ppm respectively. The corrosivity intensity, based on the combined effect of soil pH and resistivity is essentially Medium-to- Medium-High being Medium at 10 locations, Medium-High at 8 locations, and High, Medium-Low, and Low at 2 locations each. More reliable information can be obtained about soil corrosivity toward buried metallic structures if the combined effect of the soil parameters affecting soil corrosion is considered.

Open Access Original Research Article

Reconstruction of Paleoecology of Early Miocene Subsurface Deposits from Microflora in the Eboïnda Area (South-Eastern Côte d'Ivoire,West Africa)

Toe-Bi Kahou Kizito Katel, Djeya Kouamé Leger, Zoh Derrick Aurélien Behi, N’goran Jean-Paul, Koré Elysé Guede, Digbehi Zeli Bruno

Journal of Geography, Environment and Earth Science International, Page 57-66
DOI: 10.9734/jgeesi/2021/v25i530288

The early Miocene palynoflora was recovered from well P1 located in the Aboisso area, about 175 km around of Abidjan (south-eastern Côte d'Ivoire, West Africa). Pteridophyta spores, angiosperm and gymnosperm pollen grains have been identified. The main objective of this work is to inventory all the palynomorphs encountered, to propose a local palynostratigraphy and to reconstitute the paleobotany of our study area during the Tertiary formations north of the lagoon fault. The samples were processed according to the classical procedure of extraction and concentration of palynomorphs. The lithology contains brown to black clays, coarse to fine sands, and reddish to motley clays. This study showed that the dominance of freshwater ferns such as Verrucatosporites usmensis, Laevigatosporites ovatus, Polypodiaceiosporites simplex, Cingulatisporites pseudocicatricosus and leiotriletes adriensis which evokes a swampy environment. Also the development of Bombacaceae (Bombacacidites annae), and the abundance of Pteridophyte spores of the Polypodiaceae family (Verrucatosporites usmensis, Laevigatosporites ovatus, and Polypodiaceiosporites simplex) indicate the climate was tropical with alternating dry and wet periods. Early Miocene sediments are placed in a continental type environment.