Published date
Topic
Data

A new project is getting underway to map large parts of New Zealand’s coastline in remarkable detail to help communities mitigate the impacts of climate change and understand our ever-changing coastline. 

Toitū Te Whenua Land Information New Zealand (LINZ) has selected two suppliers to collect high-definition LiDAR data as part of its 3D Coastal Mapping programme.

Stuart Caie is leading the programme for LINZ and says the data will be used to create 3D maps of vulnerable and populated parts of our coastline:

“As a small island nation New Zealanders living and working near the coast are exposed to climate events and natural hazards like tsunami, and these will impact valuable infrastructure, environmental and cultural assets close to the sea, as well as coastal biodiversity.”

The two companies contracted to collect the LiDAR data are Woolpert NZ for the North Island and NV5 Geospatial for the South Island.

Areas planned to be mapped this summer include coastlines in Gisborne, Bay of Plenty, Taranaki, Manawatu-Whanganui, Hawke’s Bay, Wellington, Westland, Oamaru, Timaru, Dunedin and Southland.

Map of the North Island and South Island showing several parts of the coast that are proposed for 3D Coastal Mapping

Planes need to fly at around 500 metres above the ground when capturing the LiDAR data, so people may notice when planes are in their area.

“Coastal mapping data is used by scientists and environmental planners to better understand how the country may be impacted and help keep communities and infrastructure safe, as well as protect ocean biodiversity through improved habitat mapping.”

LINZ’s 3D Coastal Mapping programme will create baseline data for up to 40% of the coast over the next three years. The data will be made freely available on the LINZ Data Service website and the LINZ Basemaps service once processed.

LiDAR which stands for ‘light detection and ranging’ technology determines the shape of the coast and shallow sea floor below by sending pulses of light from a sensor fitted in an aircraft that measures the distance to the earth below, building up a 3D picture of the Earth's surface.

“As we’ve seen with other LiDAR data on land, the coastal data can be used to assess changes to the coast through erosion or subsidence, build-up of dirt and debris from cyclones or weather events, and land uplifting from earthquakes”, Mr Caie says.

“We know scientists are excited about this data and the modelling that it can enable, especially as storm surges are likely to become more frequent as sea-level rises in the future.

“To know how much New Zealand will be impacted, we have already begun installing global positioning receivers at sea-level gauges around the coast. These sensors measure changes in the vertical movement of the land and coupled with the sea-level gauges will allow us to work out the effect of sea-level rise over time.

“This information will go hand-in-hand with the coastal mapping data for analysis by researchers and planners”, Mr Caie says.

Data will be used to update nautical charts for maritime safety, a core part of LINZ’s hydrographic work programme.

To find out more, see 3D Coastal Mapping programme

Media contact