A Taupō company is mapping the Tongariro River, from the air.
AirVision was commissioned by the Waikato Regional Council to provide a bird's eye view of the river, using drone technology.
The data gathered could be used to calculate the volume of sediment build-up in a river bed and how much could be removed, AirVision's Mark Christensen said.
Drones can follow a specific flight, using GPS data and take thousands of images to create a 2D "orthomosiac" map.
Christensen said orthomosaic maps consist of many aerialphotos stitched together.
"The images are geo-referenced, with GPS co-ordinates recorded by the drone," Christensen said.
"The software then uses trigonometry to pinpoint where each pixel in the image should be, on the 2D map.
"When we add in surveyed ground controlled points, we can produce pixel resolution of 3cm / pixel, which is so much more detail than Google Maps or LINZ."
3D models of buildings and geographic features can also be created, if additional photography is taken.
"Distances, areas and volumes can be accurately measured by clients, using a geo-rectified 3D map," Christensen said.
Tracking sediment build-up would help track potential changes in the river.
"A sediment build-up, in a flood event, can cause a change of direction of the river to the point it can cut through and create a new river path.
"Major flooding events, like on the Tongariro River, can totally cut out whole sections of river.
"Collecting this data helps us prepare for future flood events, making communities near rivers more safe."
Drones could also access remote areas and be used to identify pest vegetation, such as trees damming rivers and streams, after significant weather events, Christensen said.
"The information gathered can inform decisions on whether or what immediate works are necessary.
"All the maps and models can then be used for to create historical records, which reference the river channels and behaviour."
He said the advantages of drone-mapping for industries and councils include fast turnaround, greater access to remote areas, a higher visual perspective, more operation efficiency.
It was also safer because it reduced the number of people heading into dangerous terrain.
In residential areas, drones could be used to map pipeline infrastructure too, he said.
Christensen said he expected drone use to grow.
"The camera technology on them, currently, is pretty standard.
"But in the future, people are going to attach all sorts of instruments to it, such as infrared and ultraviolet cameras.
"We're working on attaching sensors that can sense air quality, or take water samples from lagoons, lakes, geothermal spots.
"You might want to send a drone up to take a sample from the Mt Ruapehu crater lake, for example."
The fast computing of big data should enable better understanding and management of the environment, he said.
"The faster we can figure out what's going on, the quicker the solution can be found."
Christensen said commercial drone pilots operated differently to hobbyist drone pilots.
"We have all the required certificates and insurances to operate which allow us to operate our drones where most hobby pilots can't go.
"There are conditions and places where we have to gain permission from all the right people like aerodromes, land owners and councils."
He said tech-minded young people might be wise to investigate drone piloting and data analysis.
"It's a viable avenue for kids wanting to be in an innovative field that's changing the landscape of industries.
"The laws are always going to say, you'll need human involvement.
"Even with automation, it's one of those things where there's still gong to be jobs available for drone operators in the next 20 years."