Identification of pegmatites zones in Muiane and Naipa (Mozambique) from Sentinel-2 images, using band combinations, band ratios, PCA and supervised classification

Remote sensing has been widely used in Geological Sciences for different applications, such as to identify geological and mineralogical objects and surface alteration changes. This study aimed to analyze the Sentinel-2 potential to detect pegmatite bodies and associated alteration zones in Muiane and Naipa in Mozambique. Different remote sensing techniques were applied to a Sentinel-2 image: RGB combinations, band ratios, principal component analysis (PCA), and supervised image classification algorithms such as the Maximum Likelihood Classifier (MLC) and Support Vector Machine (SVM). MLC was used as a benchmark classifier to evaluate the performance of SVM because MLC is the predominant algorithm employed in remote sensing classification studies. For that, several statistical metrics based on the confusion matrices were computed, namely accuracy, Kappa index, precision, recall, and f-score, among others. This study allows identifying the location of pegmatites by direct identification and segregating between hydrothermally altered zones and non-altered areas through remote sensing data/techniques, supported by field data. The field campaigns allowed for validating the results obtained and verifying the pegmatites identified using Sentinel-2 data that were not previously mapped. Moreover, reflectance spectroscopy studies in the laboratory were conducted on the samples collected in the field campaigns allow to validate the adequacy of the methodology proposed in this study. The results show that the precise identification of pegmatite targets requires a high spatial resolution such as Sentinel-2 images. Thus, with the integration of high spatial and spectral resolution data, a potential level of precision and accuracy can be achieved in the study areas

Selecção de áreas de prospecção com recurso aos SIG na região de Mogovolas-Iuluti-Chalaua-norte de Moçambique

As mineralizações em pegmatitos são abundantes no Norte de Moçambique e a sua prospeção e exploração remonta, pelo menos desde o tempo de ocupação colonial o que explica o interesse das empresas mineiras na aquisição de áreas para pesquisa e exploração. O objectivo deste artigo é fazer uma análise preliminar básica, através de um Sistema de Informação Geográfica (SIG) visando a produção de mapas de favorabilidade ou previsionais. O estudo centrou-se no posto administrativo de Iuluti e Chalaua, onde são exploradas gemas (turmalinas e granadas) associadas a pegmatitos. Toda a informação sobre a cartografia geológica existente foi introduzida num SIG, e processada com uma abordagem “Data Driven” e “Knowledge Driven”, criando um mapa preditivo que identifica a favorabilidade de algumas zonas dentro da regiãoThe mineralization in pegmatites are abundant in northern Mozambique and its exploration and exploitation dates back at least from the time of colonial occupation that explains the interest of mining companies in the acquisition of areas for concession. The purpose of this article is to make a basic preliminary analysis through Geographic Information System (GIS), in order to produce maps of favorability or potential maps for many mineral commodities. The study focused on the administrative post of Iuluti and Chalaua, which is explored for gems (garnets, tourmalines). All the information about the existing geological mapping were introduced into a GIS and processed on "Data Driven” and “Knowledge Driven" approach, creating a predictive map that identifies the favorability of the region

An Optimization of the Municipal Solid Waste in Abuja , Nigeria for Electrical Power Generation

Currently, Abuja, the capital of Nigeria, is experiencing an exponential increase in municipal solid waste (MSW) generation due to its rapid population growth, level of development, and its socioeconomic status among others. Moreover, MSW is an overburden to the Abuja environment in terms of its management and health risk to the inhabitants. However, MSW is utilized by some countries as fuel for energy generation through the waste to energy (WTE) approach. In view of this, the study aims at assessing the MSW in Abuja as a potential resource for electrical power generation and distribution. This study is focused on incineration with energy recovery as an immediate solution for MSW reduction, and a supplementary answer to erratic electric power supply to the people. The proximate and ultimate analyses in combination with the modified Dulong equation were employed to determine the gross calorific value (GCV). Results showed that the GCV was evaluated as 9,085 kcal/kg and the net calorific value (NCV) was evaluated as 9,067 kcal/kg. Furthermore, the power generation potential was enumerated using 10 and 50 tons of combustible MSW to arrive at 966 kWh and 4,832 kWh, respectively.We wish to express our sincere appreciation to the Petroleum Technology Development Fund (PTDF) for their funding support with the award number (PTDF/ED/PHD/AOM/1303/17)