68 TECHNICAL
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Urban infrastructure LiDAR survey: an example survey showing manhole locations. increase in numbers demonstrates a growing need for improved urban management practices, to ensure poverty levels do not rise in line with the urban population.
One of the foremost problem’ s facing Africa’ s future is that many people do not have basic access to water and sanitation. It’ s no secret that a consistent and sustainable water supply has a direct impact on the economic growth of a country, and while the continent’ s most progressive nation, South Africa, has seen overall sanitation access levels increase from 62.3 % in 2002 to over 80 % in 2016, some areas, such as Limpopo, lag way behind at just 54 %.
The challenge facing South Africa and many of the continent’ s other developing countries lies in the retrospective work required to make current pipelines fit for purpose in densely populated areas. Modern urban planning methods often focus on new infrastructure or buildings rather than the restoration or improvement of existing utilities. The application of the latest technology is vital to help contractors understand the physical dynamics of the urban landscape where existing communities reside. Light Detection and Ranging( LiDAR) is proving to be an invaluable tool for land surveyors and planning teams who are responsible for urban regeneration projects.
In other areas, South Africa’ s decaying pipe networks are leading to townships becoming at risk of water shortages, despite dam levels being at their highest in years. Expanding connections and decades of under-investment have led to large amounts of leaks throughout the network of pipes. Water shedding practices have been used to alleviate the pressure, leading to irregular flows, with the backlog of required repairs estimated by the government to be as high as R700-billion.
LiDAR systems were originally used to measure clouds, but became well known following the use of a laser altimeter to map the surface of the moon during the Apollo 15 mission in 1971. These systems measure the amount of time taken for a light source, or laser beam, to reflect off an object and return to the unit. When combined with a global navigation satellite system( GNSS) and an inertial measurement unit( IMU) that measures linear and angular movement, LiDAR systems can collect three-dimensional( 3-D) geospatial data.
May 2017 Volume 23 I Number 3 www. plumbingafrica. co. za