Use of Remote Sensing for Mapping and Evaluation of Mining Waste Anomalies at National to Multi-Country Scale. A Case Study to Integrate Remote Sensing Information with Thematic Data Layers and National Inventories on Mining Features in Pre-Accession ...

Abstract not availableJRC.H-Institute for environment and sustainability (Ispra

Detecting Lithium (Li) Mineralizations from Space: Current Research and Future Perspectives

Optical and thermal remote sensing data have been an important tool in geological exploration for certain deposit types. However, the present economic and technological advances demand the adaptation of the remote sensing data and image processing techniques to the exploration of other raw materials like lithium (Li). A bibliometric analysis, using a systematic review approach, was made to understand the recent interest in the application of remote sensing methods in Li exploration. A review of the application studies and developments in this field was also made. Throughout the paper, the addressed topics include: (i) achievements made in Li exploration using remote sensing methods; (ii) the main weaknesses of the approaches; (iii) how to overcome these difficulties; and (iv) the expected research perspectives. We expect that the number of studies concerning this topic will increase in the near future and that remote sensing will become an integrated and fundamental tool in Li exploration

A global-scale data set of mining areas

The area used for mineral extraction is a key indicator for understanding and mitigating the environmental impacts caused by the extractive sector. To date, worldwide data products on mineral extraction do not report the area used by mining activities. In this paper, we contribute to filling this gap by presenting a new data set of mining extents derived by visual interpretation of satellite images. We delineated mining areas within a 10 km buffer from the approximate geographical coordinates of more than six thousand active mining sites across the globe. The result is a global-scale data set consisting of 21,060 polygons that add up to 57,277 km². The polygons cover all mining above-ground features that could be identified from the satellite images, including open cuts, tailings dams, waste rock dumps, water ponds, and processing infrastructure. The data set is available for download from https://doi.org/10.1594/PANGAEA.910894 and visualization at www.fineprint.global/viewer

MINERAL EXPLORATION AND SUSTAINABLE DEVELOPMENT: A CASE STUDY IN THE REPUBLIC OF SOUTH SUDAN

South Sudan, a new country formed in 2011, has been planning to develop its mineral sector by allocating exploration licenses to investors. This decision requires preliminary knowledge of geology and mineral occurrences, both of which are unavailable because the country has been engaged in a civil war for more than 50 years. Exploration of mineral resources in South Sudan has lagged behind its petroleum industry, except for artisanal gold mining, which is practiced intermittently by local communities. Freely available satellite gravity and remote-sensing data were used to map the basement architecture as well as zones of hydrothermal alteration in the Didinga Hills; both basement architecture and hydrothermal alteration are of prime importance in exploration and development of mineral resources in the study area. Qualitative interpretation of gravity data is consistent with the known geology of petroleum fields and the Precambrian basement complex. Remote-sensing data and techniques—optimal band combination, band ratioing, and principal component analysis—have been effective in extracting information related to lithology, hydrothermal alteration, and geologic structures. The resulting basic information and methods have identified additional prospective exploration areas where more detailed gravity, magnetic, electromagnetic, and seismic surveys should be carried out; this will assist decision makers in matters related to land use, mineral titles, and exploration of natural resources, and lead to prosperity for the new nation of South Sudan

Satellite remote sensing for hydrothermal alteration minerals mapping of subtle geothermal system in unexplored aseismic environment

Mapping prospective geothermal (GT) resources and monitoring associated surface manifestations can be challenging and prohibitively expensive in subtle systems especially when using conventional survey methods. Remote sensing offers a synoptic and costeffective capability for identification of GT systems. The objective of this research is to refine and develop methods of identifying unconventional GT systems by evaluating the applicability of the ASTER, Landsat 8 and Hyperion satellite data for mapping hydrothermal alteration indicator minerals as proxy for detecting subtle GT targets in unexplored aseismic settings. The study area is Yankari Park in North Eastern Nigeria, characterized by the thermal springs; Wikki, Mawulgo, Gwana and Dimmil. Spectral Angle Mapper (SAM), Linear spectral Unmixing (LSU) and Mixture Tuned Matched Filtering (MTMF) were comparatively evaluated by using image derived spectra and corresponding library spectra for mapping pixel abundance of GT indicator minerals in a novel and efficient manner. The results indicated that employing image derived spectra from field validated and laboratory verified regions of interest as reference, gives more accurate results than using library spectra around known alteration zones remotely detectable on the imagery. The MTMF provided high performance subpixel target detection with an accuracy of 50-100% and 70-100% subpixel abundance for argillicphyllic- silicic and propylitic alteration mineral assemblages respectively, as compared to less than 10% for the same endmembers when using library spectra. The MTMF is thus best suited for mapping alterations associated with subtle GT systems than the less selective LSU. The per-pixel SAM was unsuitable for target detection of alteration indicators of interest with poor overall accuracy of 33.81% and 0.24 Kappa coefficient at 0.02 radian angle. Results of mapping thermally anomalous pixels do not conform to known locations of the thermal springs signifying the limitations of the current thermal sensors in mapping low temperature GT systems even at 60m spatial resolution. However, examining the spatial correlation of the anomaly areas with the major geologic structure systems from geological map of the study area indicates a close affinity between them and with previously reported thermal gradients within heat insulating sedimentary formations. This study establishes the integrative applicability of Multispectral and Hyperspectral data for mapping subtle GT targets in unexplored regions using in-situ validated alteration mineral mapping and thermal anomaly detection. This has significant implication for the GT green energy industry as the developed methods and GT prospect map could aid the prefeasibility stage narrowing of targets for in-depth geophysical, geochemical, geothermometric and related surveys

Avaliação do potencial da restauração florestal na Amazônia Oriental: Estudos aplicados ao nordeste paraense.

O Brasil possui uma meta de restaurar 350 milhões de hectares até 2030, com métodos e técnicas que proporcionem melhores benefícios ecossistêmicos aliados ao processo de custo-eficiência e, por outro lado, detém em sua economia, atividades que requerem a supressão de extensas áreas, tais como pecuária, agricultura e mineração. Considerando os impactos gerados pela supressão da vegetação e a busca por alternativas eficientes de restauração desses ambientes, a presente tese teve por objetivo avaliar o potencial de restauração florestal na Amazônia brasileira, com enfoque na região do nordeste paraense, e propor métodos de restauração eficientes à realidade pós-mineração. Está Tese de Doutorado está dividida em seis capítulos: (1) Introdução Geral, abordando os principais aspectos presente na Tese; (2), (3) e (4) Capítulos de Pesquisa, apresentados aqui em forma de publicação cientificas, enviados a revistas internacionais de alto impacto; (5) Discussão Geral, onde abordamos os aspectos de conexão entre os capítulos de pesquisa; e (6), Capítulo de Conclusões. No primeiro capítulo foi abordado a avaliação de áreas prioritárias para a restauração do município de Paragominas, no qual foi avaliado o processo histórico de degradação em propriedades rurais e proposto restaurar Àreas de Preservação Permanentes (APP) degradadas, bem como a possibilidade de implementação de corredores ecológicos, e assim fomentar alternativas de retorno da biodiversidade. Nesse capítulo identificamos 3.472,96 km2 de propriedades rurais com APPs degradadas que devem ser recuperadas. No segundo capítulo, foi estudado o processo de sucessão florestal de uma área minerada por caulim pertencente a empresa Imerys, no município Ipixuna, caracterizada pela grande desestruturação topográfica, no qual se buscou avaliar a eficiência de um método de restauração ainda pouco difundido, com abertura de trincheiras, para avaliação da composição florística de seis espécies florestais e estoque de serapilheira após 18 meses de implantação. Os resultados demonstrados são promissores, onde a abertura de trincheiras com adição de adubação orgânica somada de adubação química nas covas foi positivo no desenvolvimento dos indivíduos plantados, apesar de haver a necessidade de se avaliar o custo-eficiência para demonstrar que a técnica pode ser utilizada em áreas extensas de mineração. No terceiro capítulo, para a mesma área em processo de sucessão pós mineração de caulim o objetivo foi avaliar a eficiência dos atributos químicos do minesoil, em função de diferentes técnicas de adubação. Os resultados demonstraram que, apesar do pouco tempo, a metodologia aplicada favoreceu ao solo boas propriedades físicas e químicas, rápido crescimento dos indivíduos plantados e ambiente favorável à regeneração natural. Dessa forma, os resultados obtidos nesses estudos podem ser replicados a outros municípios para propor políticas públicas na busca pela diminuição da degradação ambiental, assim como propor alternativas viáveis para os empreendimentos minerários que requerem de forma eficiente, restaurar os ambientes minerados.Brazil has a goal of restoring 350 million hectares by 2030, with methods and techniques that provide better ecosystem benefits coupled with the cost-efficiency process and, on the other hand, holds in its economy, activities that require the suppression of extensive areas, such as livestock, agriculture, and mining. Considering the impacts generated by suppression of vegetation and the search for efficient alternatives for the restoration of these environments, the present thesis aimed to evaluate the potential of forest restoration in the Brazilian Amazon, focusing on the northeast region of Pará, and to propose efficient restoration methods to post-mining reality. This Doctoral Thesis is divided into six chapters: (1) General Introduction, covering the main aspects present in the Thesis; (2), (3) and (4) Research Chapters, presented here in the form of scientific publications, sent to high impact international journals; (5) General Discussion, where we address the aspects of connection between the research chapters; and (6), Conclusions Chapter. In the first chapter, the evaluation of priority areas for restoration in the municipality of Paragominas was addressed, and the historical process of degradation in rural properties was evaluated and it was proposed to restore degraded Permanent Preservation Areas (PPA), as well as the possibility of implementing ecological corridors, and thus foster alternatives for the return of biodiversity. In this chapter, we identified 3,472.96 km2 of rural properties with degraded PPA’s that must be recovered. In the second chapter, the process of forest succession of an area mined by kaolin belonging to the company Imerys, in Ipixuna municipality, was studied, characterized by the great topographical disruption, in which it sought to evaluate the efficiency of a restoration method that is still not very widespread, of trenches, to evaluate the floristic composition of six forest species and litter stock after 18 months of implantation. The results demonstrated are promising, where the opening of trenches with the addition of organic fertilizer plus chemical fertilizer in the pits was positive in the development of the planted individuals, although there is a must to evaluate the cost-efficiency to demonstrate that the technique can be used extensive mining areas. In the third chapter, for the same area in succession process after kaolin mining, the objective was to evaluate the efficiency of the chemical attributes of minesoil, according to different fertilization techniques. The results showed that, despite the short time, the applied methodology favored the soil with good physical and chemical properties, rapid growth of planted individuals and a favorable environment for natural regeneration. In this way, the results obtained in these studies can be replicated to other municipalities to propose public policies in the search for the reduction of environmental degradation, as well as to propose viable alternatives for mining enterprises that require efficiently, to restore the mined environments

High resolution aerial and field mapping of thermal features in Ragged Hills, Yellowstone National Park

High resolution aerial images taken in a cost and time effective way from low-flying platforms were used to map a hydrothermal area in the Yellowstone National Park. The mapping area called Ragged Hills is located in the Norris Geyser Basin, a major hydrothermal basin of the Park famous for its great diversity and number of thermal features. Because of an increasing thermal activity since the early 1990s numerous hydrothermal features of different sizes developed in Ragged Hills. Various changes in size and chemistry of the thermal features were observed during sporadic ground surveys. No detailed maps of the thermal inventory existed because of the difficulties in mapping this rapidly changing area by standard ground survey methods. Mapping the features in a short time to get a status quo of the feature’s form and size was the goal of the present work. Two different low-flying platforms were used during this project – a helium filled balloon and a single engine airplane (Cessna 172). To be able to georeference the aerial photos later a grid of ground control points was laid out and the points were surveyed by differential GPS as well as by theodolite. Deviations between both methods were on average 37 cm (Northing) and 61 cm (Easting). The overflights with the airplane were more cost intensive, requiring aircraft rental and trained pilots. Because the obtained images were in most cases blurred, they were served as overview only. Nevertheless the pixel resolution was quiet good with an average of 6 cm. Besides the true color images taken by a digital camera, also thermal pictures were taken from the airplane with a spatial resolution of 1.2 m. The balloon survey provided a costeffective and easy-to-handle alternative. Major restrictions are only the transport of the helium bottles to the study site, and the requirements for calm wind conditions. From an altitude of 50 to 80 m sharp and high resolution images were obtained. About 45 pictures were used to create a mosaic of the whole study area with a pixel resolution of 2.5 cm. No high-resolution thermal pictures could be taken from the balloon because the weight of the camera (3.9 kg) exceeded the balloon’s lifting capacity (1.5 kg). The created high-resolution aerial overview was included in a digital atlas together with topography and geological maps, older lowresolution aerial pictures, and hydrochemical data. The following diploma thesis gives an overview about available low-flying platforms and their individual advantages and disadvantages, describes the methods used in detail and evaluates them regarding expenditure and time it took to realize the individual working steps. Furthermore an interpretation of mapping and hydrochemical data is presented.Förderkreis Freiberger Geologie e.V.researc