by P. Azinwi Tamfuh, E. Ndah Musi, S.C. Nguemhe Fils, K.I. Ateh, A.B. Aye, E. Tata, L. E. Mamdem, B. Kenzong, G. D. Kouankap Nono and Dieudonné Bitom
Original Research
Artisanal mining is often associated with land use and land cover (LULC) changes like deforestation, open pits, health hazards, heavy metals contamination of land, land degradation, dust and noise pollution, soil instability, climate change, etc. This research aims to monitor LULC changes between 2018 and 2022 in East Cameroon due to artisanal gold mining activities, assessing the dynamics between LULC change types and the extent of change with time. Sentinel-2 images for 2018, 2020, and 2022 were used to examine LULC patterns at per-pixel scale with a post-classification change detection technique based on a cross matrix of changes. Supervised classification was carried using maximum likelihood algorithm of five LULC classes (bare land, vegetation, water bodies, settlements and mining activities). The results revealed spatio-temporal change patterns that have taken place in Betare-Oya. It was observed that the area under mining activities has increased from 2042.32 ha in 2018 to 3197.03 in 2020 and experienced a sharp decline to 2008.72 ha in 2022 probably as a result of the COVID-19 pandemic; with an overall percentage change from 3.95 % to 6.18 % and 3.89 % for 2018, 2020 and 2022, respectively. Also, results showed the change in vegetation from 21718.36 ha in 2018 to 16189.78 ha in 2020. In 2022, vegetation slightly increased to 16563.88 ha as a result of the fluctuation in mining activities, showing an inverse interaction between mining activities and vegetation. This study emphasizes the usefulness of Sentinel-2 data and highlights the data processing methods for long-term monitoring of the impacts of artisanal mining activities on the environment. This research will add to already existing database on LULC changes in Cameroon as a result of mining activities.
Journal of Geosciences and Geomatics. 2024, 12(1), 12-23. DOI: 10.12691/jgg-12-1-3
Pub. Date: March 29, 2024
by Maro G.P., Mbwambo S.G., Monyo H.E. and Mosi E.J.
Original Research
Most major agricultural research stations in Tanzania have adopted the geographic information systems (GIS). Tanzania Coffee Research Institute (TaCRI) was late to come on board because its establishment does not include a cartographic unit. Collaboration with TARI-Mlingano in 2008/09 enabled the initiation of a mini-GIS unit at Lyamungu. One of its tasks was to develop digital maps of the TaCRI substations scattered over major coffee zones in Tanzania. Four substations were chosen to start with. For Lyamungu, a non-georeferenced paper map was scanned and 8 control points selected, whose x-y coordinates were taken with a GPS tool. They were loaded into Excel spreadsheet and saved as a .csv file. The image and the point shapefile were properly aligned in ArcMap 10.7.1 and digitized onscreen. Ugano, Mbimba and Mwayaya maps were digitized from satellite images remotely sensed with Google Earth Pro, saved first as .kmz files, and converted in ArcMap to features and later to shapefiles. Land use was elaborated using expert knowledge. The resultant was the first ever digital maps of the four substations. Created shapefile layers included boundary, rivers, roads and fields (categorized as coffee land, other crops, forest reserve, other reserves, wetlands and waterbodies, nurseries and general infrastructure). Land use per category showed to have a bearing on station history, current land ownership status and staff population. Percentage land assigned to coffee decreased in the order Lyamungu > Mwayaya > Ugano > Mbimba. This work has formally introduced TaCRI to the GIS world – an important step as GIS is becoming ubiquitous in global research, planning and problem solving. It was also a very good starting experience with ArcMap and Google Earth.
Journal of Geosciences and Geomatics. 2024, 12(1), 6-11. DOI: 10.12691/jgg-12-1-2
Pub. Date: March 21, 2024
by Hesham Mohamed Abd al-Salam Yehia
Original Research
Earthquakes pose a significant threat to human lives and infrastructure worldwide. In recent years, there has been growing interest in developing innovative technologies to mitigate the destructive effects of earthquakes. This manuscript explores the potential of using domes produced through Octa-H, a material known for its unique properties, to absorb harmful waves and reduce the risk of earthquakes. The manuscript provides an overview of the underlying principles, presents experimental evidence, and discusses the implications of this technology on seismic safety. The results showed that absorption of harmful UVC rays significantly reduced the risk of potential earthquakes according to the Modeling system. This manuscript sheds light on the potential of using Octa-H domes to absorb harmful waves and mitigate the risk of earthquakes. It provides a foundation for future studies and encourages further advancements in earthquake-resistant technologies for the benefit of global seismic safety.
Journal of Geosciences and Geomatics. 2024, 12(1), 1-5. DOI: 10.12691/jgg-12-1-1
Pub. Date: February 02, 2024