A new high-resolution ground mapping dataset of the Manuherikia catchment and surrounding areas will help experts assess characteristics of natural hazards.

Covering a total of 3935 sq km of land, the high-resolution 3D ground elevation data for the catchment is available online, via the Toitū Te Whenua Land Information New Zealand (LINZ) Data Service and Open Topography websites.

Otago Regional Council spatial analyst Andrew Welsh said the completion of this geospatial dataset mapping is an invaluable tool in identifying, mapping and managing natural hazards, be it flooding, erosion or landslips. 

The Central Otago segment completes the capture for the (LINZ) Provincial Growth Fund (light detection and ranging) LiDAR Project in Otago.

The combined Dunedin and Mosgiel, Coastal Otago and Manuherikia Catchment data sets now cover more than 8190 km2 of land.

The programme is based on partnerships between Toitū Te Whenua and 10 councils and is using LiDAR technology to capture high-definition data about the shape of the land.

Toitu Te Whenua location data analyst Abbey Douglas was asked how LiDAR can assist with floods, as has been seen recently across the North Island.

“LiDAR provides accurate, high-resolution elevation of the ground surface, which is essential for reliable river and stormwater flood modelling. Such models are critical for planning and developing infrastructure which is resilient to flood events,” she said.

Toitū Te Whenua senior technical leader elevation and imagery Bjorn Johns said the LiDAR project would ultimately result in detailed three-dimensional imagery for 80 percent of the country once it was completed in 2024.

He said having baseline elevation data for so much of the country will make it easier to assess changes after major events.

The significant alterations in the terrain caused by weather and other events, such as earthquakes, also made a compelling case for ongoing LiDAR so public data remained up to date.

Many groups can benefit from using the data set, including ecologists for wetland mapping or for engineers to inform flood protection planning. 

It provided farm-scale land information to benefit the agriculture and forestry sectors, and was widely used for development, engineering, architecture, and design applications by the private sector.