Water

Dam design and impact assessment

Aerial LiDAR is deployed to survey proposed dam locations. The acquired data can be used for planar flood model analysis to calculate the maximum flooding that will occur for a given dam design, the volume of water that will be held, and the impact on the local population. Terrestrial laser survey technology can be used for smaller dam sites, particularly in mountainous areas that are hard to survey using conventional methodologies.

Floodplain mapping

Through deployment of fixed-wing aircraft with high resolution remote sensing equipment we deliver topographic mapping of floodplains for use by hydrologists in floodplain analysis exercises. This includes hydrological enforcement during the production stage of our Digital Terrain Models (hydro DTMs) to ensure that water will follow its ‘true’ path in the survey dataset through culverts and under bridges etc. In a standard DTM, the presence of these features would cause the unnatural pooling of water on the upstream side.

Water transmission pipelines

Through our helicopter acquisition capability, Network Mapping are experts in the provision of high resolution and accuracy datasets for the engineering design of linear assets. The survey information can be used by design consultants to optimise the alignments of the pipelines to obtain Bill of Quantity reductions.  

Coastal inundation mapping

Sea level rise, increased storm intensity (with storm surge) and changes in inland rainfall runoff are all likely to occur under the current minimum impact IPCC climate change scenario with potential impacts including flooding, beach erosion and salt water inundation. Airborne LiDAR and its geospatial framework find a role in providing baseline information for decision support in the range of adaptation and mitigation activities that are required to overcome this serious threat. They allow decision makers to understand:

Where are the pieces of critical transport and communications infrastructure that will be affected by a sea level rise?

Where must we update water barriers such as levies in order to deal with increased storm runoff and tide surges?

Where will we see coastal vulnerability in a climate change scenario based on sea level rise, increased tide reach and storm surge impacts?

Water shed assessment

Point coverage generated from LiDAR data is converted into a ‘hydrologically correct’ Digital Terrain Model (DTM), which takes into account the effect that features such as culverts or bridges have on flow direction. Flow direction is calculated in a GIS platform through the use of complex algorithms, which assess how water flows from each cell to its steepest down-slope neighbour.