scholarly journals Mapping Mining Areas in the Brazilian Amazon Using MSI/Sentinel-2 Imagery (2017)

2018 ◽  
Vol 10 (8) ◽  
pp. 1178 ◽  
Author(s):  
Felipe de Lucia Lobo ◽  
Pedro Walfir M. Souza-Filho ◽  
Evlyn Márcia Leão de Moraes Novo ◽  
Felipe Menino Carlos ◽  
Claudio Clemente Faria Barbosa
Keyword(s):  
Environmental Impacts ◽  
Brazilian Amazon ◽  
Mining Area ◽  
Current Status ◽  
Small Scale ◽  
Detection Accuracy ◽  
Mining Areas ◽  
Geography Information ◽  
Sentinel 2A ◽  
Sentinel 2

Although mining plays an important role for the economy of the Amazon, little is known about its attributes such as area, type, scale, and current status as well as socio/environmental impacts. Therefore, we first propose a low time-consuming and high detection accuracy method for mapping the current mining areas within 13 regions of the Brazilian Amazon using Sentinel-2 images. Then, integrating the maps in a GIS (Geography Information System) environment, mining attributes for each region were further assessed with the aid of the DNPM (National Department for Mineral Production) database. Detection of the mining area was conducted in five main steps. (a) MSI (MultiSpectral Instrument)/Sentinel-2A (S2A) image selection; (b) definition of land-use classes and training samples; (c) supervised classification; (d) vector editing for quality control; and (e) validation with high-resolution RapidEye images (Kappa = 0.70). Mining areas derived from validated S2A classification totals 1084.7 km2 in the regions analyzed. Small-scale mining comprises up to 64% of total mining area detected comprises mostly gold (617.8 km2), followed by tin mining (73.0 km2). The remaining 36% is comprised by industrial mining such as iron (47.8), copper (55.5) and manganese (8.9 km2) in Carajás, bauxite in Trombetas (78.4) and Rio Capim (48.5 km2). Given recent events of mining impacts, the large extension of mining areas detected raises a concern regarding its socio-environmental impacts for the Amazonian ecosystems and for local communities.

scholarly journals The outbreak of illegal gold mining in the Brazilian Amazon boosts deforestation

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Juliana Siqueira-Gay ◽  
Luis E. Sánchez
Keyword(s):  
Gold Mining ◽  
Brazilian Amazon ◽  
Small Scale ◽  
Political Pressure ◽  
Deforestation Rate ◽  
Mining Areas ◽  
Mineral Supply ◽  
Regional Policies ◽  
Illegal Mining ◽  
Conservation Of Biodiversity

AbstractIncreased prices and political pressure are boosting illegal gold mining in the Brazilian Amazon, threatening forests, indigenous people, and conservation of biodiversity in protected areas. The rate of illegal mining deforestation increased more than 90% from 2017 to 2020, reaching 101.7 km2 annually in 2020 compared to 52.9 km2 annually in 2017. In that period, illegal mining deforestation rate grew more than the rate of clearing within mining leases. While formal mining is required to comply with environmental regulations, most small-scale or artisanal mining and especially illegal mining areas are abandoned after reserves are exhausted, without proper rehabilitation. Deforestation due to illegal mining is likely to increase in the next years, calling for coordination between local and regional policies as well as for strengthening and expanding international mechanisms to increase traceability of mineral supply chains with certification schemes to help to curb illegal mining.

scholarly journals THE IMPACT OF THE 2000 LAND REFORM PROGRAMME ON THE CAPITAL BLOCK, POPULARLY KNOWN AS THE ‘NEW MALAWI’

2016 ◽  
Vol 2 (1) ◽  
pp. 15-25
Author(s):  
Calvin Phiri ◽  
Njabulo Bruce Khumalo ◽  
Mehluli Masuku
Keyword(s):  
Land Reform ◽  
Qualitative Methodology ◽  
Farming Systems ◽  
Mining Area ◽  
Small Scale ◽  
Mining Areas ◽  
Reform Programme ◽  
Foreign Origin ◽  
The Government ◽  
The Impact

The 2000 land reform programme implemented by the government of Zimbabwe came with an initiative of acquiring enormous hectares of white-owned farmland and distributing it on a massive scale to small-scale farmers. Indeed the greater part of the land was taken from the white commercial farmers and distributed to the majority black Zimbabweans, leaving only a small share of the farmland in the hands of the whites. The land reform programme, undoubtedly, benefited Zimbabweans. In Zimbabwe, especially in mining areas, there are classes of Zimbabweans, those who originate from Zimbabwe, as well as those who are of foreign origin, but are Zimbabweans by birth. Zimbabweans by birth who are of foreign origin occupied an allocated A2 farm, Capital Block, located near a cement mining area, Colleen Bawn. Most of them were of Malawian origin, and the area is now popularly known as ‘New Malawi’. This study sought to investigate how Zimbabweans of foreign origin benefited from the 2000 land reform programme. The article further sought to reveal the diverse farming systems as well as Indigenous Knowledge (IK), which were passed on from the forefathers who were born in Malawi, but migrated to Zimbabwe’s mining areas in search for employment in the then Rhodesia around 1960. A qualitative methodology was used in this research, in which oral history interviews were conducted with the people living in the area of the ‘New Malawi’. The study revealed that most of the land was being used for farming purposes. Beneficiaries of the programme had become self-dependent. The study further revealed that there was knowledge sharing among the beneficiaries of different foreign origins including Zambia, Malawi, Mozambique, Botswana and those of Zimbabwean origin. Based on the findings of the study, it was concluded that the programme benefited a number of people of foreign origins who were now Zimbabweans by birth and Zimbabweans by both birth and origin were happy with these people benefiting, a situation which shows the extent to which Zimbabweans are tolerant of foreigners.

scholarly journals Alleviating some Environmental Impacts resulting from Artisanal and Small-scaleMining Sector: A Critical Review

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
R.V. Byizigiro ◽  
M. Biryabarema ◽  
G. Rwanyiziri
Keyword(s):  
Environmental Impacts ◽  
Land Reclamation ◽  
Open Water ◽  
Integrated Approach ◽  
Research Field ◽  
Small Scale ◽  
Mining Sector ◽  
Mining Areas ◽  
Mine Sites ◽  
New Research

This paper highlights the importance of transforming Artisanal and Small-scale Mining (ASM) sector into a more sustainable enterprise and shows  the reclamation of despoiled mined sites as an opportunity to return land to beneficial uses which do not compromise future development of the sites. It presents some of environmental impacts produced by ASM and the contribution of a geomorphological approach to alleviate them. The methodology consisted of the review supported by field survey in small-scale mining areas to summarize the most relevant scientific findings and the importance of stabilizing the land that will support sustainably reclamation structures. The impacts include haphazard excavations with no land reclamation plan, pits, trenches inadequately protected, siltation of open water bodies, soil and rock wastes, negative change of soil properties, and accelerated erosion of the mine sites. To transform the sector into a more responsible industry, ASM has to be placed within two integrated perspectives: (i) building the capacity of ASM sector, and (ii) promoting restoration approach by building a critical knowledge mass through collaboration of relevant stakeholders, with emphasis on multidisciplinary approach.The study opens a relevant new research field and emphasises on the collaboration of mining stakeholders including local communities to develop an integrated approach to address challenges that ASM industry is facing in developing countries. This review highlights the impacts of small-scale mining sector on land use potentials and it is essentialcontribution towards the sustainability of ASM industry and reclamation of despoiled mined lands. Key Words: small-scale mining sector, environmental impact, geomorphologic approach, sustainability

scholarly journals Cloud and Cloud-Shadow Detection for Applications in Mapping Small-Scale Mining in Colombia Using Sentinel-2 Imagery

2021 ◽  
Vol 13 (4) ◽  
pp. 736
Author(s):  
Elsy Ibrahim ◽  
Jingyi Jiang ◽  
Luisa Lema ◽  
Pierre Barnabé ◽  
Gregory Giuliani ◽  
...  
Keyword(s):  
Rural Areas ◽  
Bare Soil ◽  
Shadow Detection ◽  
Cloud Base ◽  
Support Vector ◽  
Small Scale ◽  
Mining Sites ◽  
Mining Areas ◽  
Sensor Geometry ◽  
Sentinel 2

Small-scale placer mining in Colombia takes place in rural areas and involves excavations resulting in large footprints of bare soil and water ponds. Such excavated areas comprise a mosaic of challenging terrains for cloud and cloud-shadow detection of Sentinel-2 (S2A and S2B) data used to identify, map, and monitor these highly dynamic activities. This paper uses an efficient two-step machine-learning approach using freely available tools to detect clouds and shadows in the context of mapping small-scale mining areas, one which places an emphasis on the reduction of misclassification of mining sites as clouds or shadows. The first step is comprised of a supervised support-vector-machine classification identifying clouds, cloud shadows, and clear pixels. The second step is a geometry-based improvement of cloud-shadow detection where solar-cloud-shadow-sensor geometry is used to exclude commission errors in cloud shadows. The geometry-based approach makes use of sun angles and sensor view angles available in Sentinel-2 metadata to identify potential directions of cloud shadow for each cloud projection. The approach does not require supplementary data on cloud-top or bottom heights nor cloud-top ruggedness. It assumes that the location of dense clouds is mainly impacted by meteorological conditions and that cloud-top and cloud-base heights vary in a predefined manner. The methodology has been tested over an intensively excavated and well-studied pilot site and shows 50% more detection of clouds and shadows than Sen2Cor. Furthermore, it has reached a Specificity of 1 in the correct detection of mining sites and water ponds, proving itself to be a reliable approach for further related studies on the mapping of small-scale mining in the area. Although the methodology was tailored to the context of small-scale mining in the region of Antioquia, it is a scalable approach and can be adapted to other areas and conditions.

scholarly journals Comparing Sentinel-2 MSI and Landsat 8 OLI Imagery for Monitoring Selective Logging in the Brazilian Amazon

2019 ◽  
Vol 11 (8) ◽  
pp. 961 ◽  
Author(s):  
Thaís Almeida Lima ◽  
René Beuchle ◽  
Andreas Langner ◽  
Rosana Cristina Grecchi ◽  
Verena C. Griess ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Forest Disturbance ◽  
Brazilian Amazon ◽  
Selective Logging ◽  
Small Scale ◽  
Landsat 8 ◽  
Forest Disturbances ◽  
Data Logging ◽  
Study Sites ◽  
Sentinel 2

Imagery from medium resolution satellites, such as Landsat, have long been used to map forest disturbances in the tropics. However, the Landsat spatial resolution (30 m) has often been considered too coarse for reliably mapping small-scale selective logging. Imagery from the recently launched Sentinel-2 sensor, with a resampled 10 m spatial resolution, may improve the detection of forest disturbances. This study compared the performance of Landsat 8 and Sentinel-2 data for the detection of selective logging in an area located in the Brazilian Amazon. Logging impacts in seven areas, which had governmental authorization for harvesting timber, were mapped by calculating the difference of a self-referenced normalized burn ratio (ΔrNBR) index over corresponding time periods (2016–2017) for imagery of both satellite sensors. A robust reference dataset was built using both high- and very-high-resolution imagery. It was used to define optimum ΔrNBR thresholds for forest disturbance maps, via a bootstrapping procedure, and for estimating accuracies and areas. A further assessment of our approach was also performed in three unlogged areas. Additionally, field data regarding logging infrastructure were collected in the seven study sites where logging occurred. Both satellites showed the same performance in terms of accuracy, with area-adjusted overall accuracies of 96.7% and 95.7% for Sentinel-2 and Landsat 8, respectively. However, Landsat 8 mapped 36.9% more area of selective logging compared to Sentinel-2 data. Logging infrastructure was better detected from Sentinel-2 (43.2%) than Landsat 8 (35.5%) data, confirming its potential for mapping small-scale logging. We assessed the impacted area by selective logging with a regular 300 m × 300 m grid over the pixel-based results, leading to 1143 ha and 1197 ha of disturbed forest on Sentinel-2 and Landsat 8 data, respectively. No substantial differences in terms of accuracy were found by adding three unlogged areas to the original seven study sites.

Managing the impacts of mining on Ghana’s water resources from a legal perspective

2018 ◽  
Vol 1 (3) ◽  
pp. 156-165 ◽  
Author(s):  
Nasirudeen Abdul Fatawu
Keyword(s):  
Surface Water ◽  
Water Resources ◽  
Environmental Protection Agency ◽  
Large Scale ◽  
Small Scale ◽  
Mining Activities ◽  
Protection Agency ◽  
Environmental Laws ◽  
Mining Areas ◽  
Legal Perspective

Recent floods in Ghana are largely blamed on mining activities. Not only are lives lost through these floods, farms andproperties are destroyed as a result. Water resources are diverted, polluted and impounded upon by both large-scale minersand small-scale miners. Although these activities are largely blamed on behavioural attitudes that need to be changed, thereare legal dimensions that should be addressed as well. Coincidentally, a great proportion of the water resources of Ghana arewithin these mining areas thus the continual pollution of these surface water sources is a serious threat to the environmentand the development of the country as a whole. The environmental laws need to be oriented properly with adequate sanctionsto tackle the impacts mining has on water resources. The Environmental Impact Assessment (EIA) procedure needs to bestreamlined and undertaken by the Environmental Protection Agency (EPA) and not the company itself.

scholarly journals Multifunctional Activities of Gold Nanoparticles Biosynthesized Using Bacteria Isolated from Mining Areas

2021 ◽  
Vol 11 (8) ◽  
pp. 3670
Author(s):  
Chih-Yu Chen ◽  
Yung-Chu Chang ◽  
Teh-Hua Tsai ◽  
Man-Hai Liu ◽  
Ying-Chien Chung
Keyword(s):  
Gold Nanoparticles ◽  
Mining Area ◽  
Synthesis Process ◽  
Average Particle ◽  
Bifidobacterium Lactis ◽  
E Coli ◽  
Mining Areas ◽  
Skin Cells ◽  
Study Results ◽  
Antityrosinase Activity

Research on gold nanoparticles (AuNPs) has often focused on their physical, chemical, and crystalline characteristics. Commercial AuNPs have been applied in the diverse fields of biomedicine, catalysis, photovoltaics, and sensing. In this study, we explored the various activities of AuNPs to widen their applicability. This paper presents a simple and rapid synthesis process of AuNPs with bacteria isolated from a gold mining area. We also investigated the optimization of reaction parameters for AuNP synthesis. The study results revealed that among the isolated strains, Bifidobacterium lactis and Escherichia coli demonstrated the highest capabilities of AuNP synthesis. The optimal pH values for AuNP synthesis by B. lactis (BLAuNPs) and E. coli (ECAuNPs) were 5.0 for 72 h of incubation and 8.0 for 24 h of incubation. The average particle sizes of ECAuNPs and BLAuNPs were 4.2 and 5.6 nm, respectively. Furthermore, these biogenic AuNPs were found to be stable with no aggregation after 3 months of storage. BLAuNPs and ECAuNPs exhibited high levels of antimicrobial, antioxidant, photocatalytic, and antityrosinase activity. Moreover, they were noncytotoxic to skin cells even at 100% melanin inhibitory concentrations. Considering the demonstrated multifunctional activities of AuNPs, BLAuNPs and ECAuNPs have promising potential for commercialization.

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