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Product examples - Witbank


Change of the mining footprint through time - eMalahleni, South Africa

This product shows how the amount of land used by mining (i.e. the footprint) has changed between 1989 and 2010 in eMalahleni municipality and the neighbouring area. Although the shape of the mining footprint differed between 1989 and 2002, the total area occupied by mining remained largely unchanged. However, between 2002 and 2010, the total area occupied by mining more than doubled from 16,000 hectares to 40,000 hectares. The land occupied by mining was mapped through visual interpretation of satellite imagery (i.e. Landsat TM).
The product relates to indicator A1 Total land used by mining.

Residential land use around mining areas - eMalahleni, South Africa
This product shows residential developments (both formal and informal) around the mining areas in the eMalahleni municipality and neighbouring area. Residential developments within 500m of mining areas are identified in yellow. These show the area potentially most at risk from associated issues such as heavy truck traffic, structural damage and dust pollution.
Mining areas and formal and informal residential developments were mapped through visual interpretation from satellite imagery (i.e. Landsat TM and SPOT). For comparison, residential developments from the 2011 census are also shown in the insets. These comparisons show that satellite imagery is a useful tool for mapping and also monitoring residential developments and urban planning.
The product relates to indicators A4 Residential land use (residential land use around mining areas) and A5 Informal settlements (sprawl of squatters areas).
Urban Footprint - eMalahleni, South Africa
This product shows urban areas (residential and industrial) in the eMalahleni municipality that have been automatically mapped using Synthetic-Aperture Radar (SAR) data. Due to the high resolution capability of TerraSAR-X, individual buildings can be identified in the images. Satellites like TerraSAR-X regularly
record new images, which means that the extent of urban areas and how these change can easily be monitored over time.
Further analyses and combinations with other data allow different types of urban structures and residential developments to be identified. This information can be used to support local and regional planning activities. It can also be used to gain a better understanding of the societal issues associated with mining, particularly the proximity of buildings to mining areas.
The product can be related to indicators A4 Residential land use (residential land use around mining areas) and A5 Informal settlements (sprawl of squatters areas)
Mining and areas of ecological importance - eMalahleni, South Africa
This product shows mining areas in relation to areas of ecological importance in the eMalahleni municipality. It shows that mining occurs close to and coincides with many areas of significant ecological importance. In these areas, mining-related issues such as air pollution, land loss and degradation, and acid mine drainage (AMD) could damage the natural habitat and therefore affect both species diversity and numbers.
The land occupied by mining was mapped through visual interpretation of satellite imagery (i.e. Landsat TM). The habitat classification information was adapted from that contained in the eMalahleni municipality Geographical Information System (GIS).
The product relates to indicator A6 Sites set aside and protected areas.
Dust pollution - eMalahleni, South Africa

This product shows content of four metals measured in street dust samples collected in eMalahleni in February 2011.
Street dust is a complex mixture of different of both natural and anthropogenic origin. Dust particles of natural origin include soils, volcanic ash, ash, pollen, plant remains and smoke from forest fires. Anthropogenic dust particles originates from weathering and abrasion of man-made materials (e.g. asphalt, concrete), demolition or construction activities, metal and energy production (e.g. smelters, coal-burning power stations), agriculture and road traffic (e.g. wear of brake pads and tyres, fuel combustion).
Dust produced through these various mechanisms is first released into the atmosphere before being deposited at street level, and then subsequently remobalised by wind or passing traffic, for example. As a result, street dust particles often form a major component of the air that we breath. However, street dust can contain high amounts of toxic metals, especially in urban environments and close to busy roads and industrial areas. Accordingly, dust containing high levels of toxic metals can pose a health risk, particularly in young children, because such metal can easily enter into the blood stream through the ingestion or inhalation of the relatively fine-grained dust particles. Additionally because some these toxic metals are easily dissolved in water, the runoff produced following a rainy period can lead to contamination of the surface water and potentially harm aquatic life. By analysing the chemical composition of the deposited street dust, we are able to identify its potential source (e.g. vehicles)
The product relates to indicator D1 Aerosols (particle concentration in off-site air).

Acid mine drainage contamination potential - eMalahleni, South Africa
This product assesses the potential effect of acid mine drainage (AMD) on water quality. It shows where minerals associated with AMD occur (in 2011) in relation to where surface water flows. It also shows the potential downstream flow paths of AMD contamination from several sources, and pre-existing contaminated surface water.
AMD-producing minerals frequently occur close to drainage channels, potentially putting them at risk of contamination. Possible AMD-producing minerals and contaminated water were mapped using satellite imagery (World View II) and aerial photography, respectively. Drainage channels and the potential downstream flow paths were mapped using a 1-m Digital Elevation Model.
This product relates to indicator E4 Acid Mine Drainage generation potential (distribution of sulphidic iron minerals).
Density of roads per square km - eMalahleni, South Africa

This product shows the road infrastructure and the possible impact it has on the landscape in the eMalahleni municipality. The total length of the road within a given area can be used as a measure of how fragmented (or divided) the landscape is, with large values indicating a high degree of land fragmentation. A degree of land fragmentation can be seen in the main urban area of Witbank and in developments that appear to be coal-related (e.g. mining areas and power stations). Land fragmentation can cause disturbance of migratory species, constraints on farming and traffic disturbances to communities.
The road infrastructure was mapped using satellite imagery (i.e. SPOT), and the length of road per square kilometer was subsequently derived from this.
The product relates to indicator F2 Land fragmentation by transport infrastructure.

Geotechnical hazards and ground stability - eMalahleni, South Africa
This product shows high resolution elevation data from an airborne system called LiDAR, along with aerial photos and satellite imagery from WorldView II.
The high resolution elevation data enables subtle features on the ground (such as sink holes) to be identified, many of which are the result of underground mining that may cause some ground movement or mining-related subsidence. In this map, the cross section in the upper left inset box shows where the ground has moved due to underground mining. The insets also include slope maps derived from the elevation data. These indicate the
steepness of the terrain; this in turn is a factor for stability and can highlight the location of collapse structures or areas at potential risk of collapse.
This relates to Indicator G2 Geotechnical hazards and ground
Geotechnical hazards: Mining-related fires

This product shows the night-time surface temperature as measured using an airborne thermal infra-red camera. While ground measurements can provide only local information, an airborne survey allows complete coverage of a much larger area. This information can be used to locate high temperature anomalies that potentially relate to subsurface coal fires in mining areas. Repeat-measurements can support monitoring of known coal fires and their severity, as well as locating new fires. Such analysis can take advantage of ground stability data, by linking
collapse structures to high temperature events to provide a better understanding of the subsurface conditions (see upper left map inset).
Data processing and product compilation was done by KOPANO. The measured temperatures were validated against ground survey reference measurements of different land-cover types.
The product relates to indicators G4 Geotechnical Hazards and Accidents: Underground and mining waste
deposit fires.