Case Studies Environmental Projects


Dust Pollution Mapping – Namibia


Objective of the Project:
The worldwide only smelter for copper processing ore containing arsenic is based in Namibia north of Windhoek. For a study to clean and reduce dust pollution Dimap was engaged to map typical dusts in their distribution over the area around the plant and to provide this data to the environmental consultants.

Technical Solution:
In the first phase of a ground study, typical spectrograms for the main dust components were recorded in the surroundings of the plant. The data were then compared with lab samples for the same materials, recorded in the HK hyperspectral laboratory of Dimap.

In a second step, Dimap was collecting data with airborne Hyperspectral sensors in the range between 400 and 2500nm with a pixel resolution of 50cm and 2m. The data were orthorectified and atmospherically corrected and afterward processed with Mixed Tunes Matched Filtering and Spectral Angle Mapper to identify the abundance of the target materials within each pixel.

While the flight operations in the hot conditions were challenging the main dust pollutions could be mapped over the area. They are showing the effect of wind transport but even more of the transport based on truck traffic between the processing plant and the installations around like the railway station.




Figure 4: Top Material detection around Tiling Dams shows on the right top site a deposit of different plant waste and on the left site the open-to-wind transport materials of the tiling dam; a little map showing distributions of different target spectra over the larger area with the plant in the center and the urban area in the south. Infrastructures used by the plant are noticeable as well as the center of concentration of dust around the installations and the railway station (red areas).


All copyrights with Dimap – 2014


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