04 April 2023, 10:49 PM
New state of the art technology including remote web cameras, drones and Space Time Image Velocimetry (STIV) software currently being trialed around Southland, will allow safer and more accurate monitoring of rivers in flood, according to Environment Southland (ES).
ES team leader hydrological response Chris Jenkins said images captured from remote cameras and drones would provide efficiencies for monitoring staff as well as useful information for Southland communities.
“For staff, it means a safer way of capturing information during flooding as there’s no need to travel to the location."
"This avoid putting people at risk in flooded waterways or them being cut off by flooded roads."
"The images captured by web cameras at our river monitoring sites will add to the data already available that helps farmers and others make decisions, particularly during floods.”
The STIV equipment had initially been trialled in Makarewa, and following testing, was installed at two sites in early 2021; one the Waikaia River and one on the Waikaka River.
The site at the Waikaia River at Piano Flat was intended to provide data on high flows when road access is cut off.
“The difficulty in accessing this site at high flows has meant we have only been able to measure 11 flows above 40 cumecs (cubic metres per second) since 1956."
"Since using the new equipment at Piano Flat, we already have 55 measurements above 40 cumecs, including the capture of the highest measured flow at 240 cumecs last week (20 March)."
“There’s no way we would have been able to gather data like that with our traditional methods of flow measurement as the road is cut off when it gets to 180 cumecs,” Jenkins said.
The STIV technology can be captured by a fixed camera or drone, and the videos are then run through computer software that estimates the water’s speed and provides real-time river flow information.
Fixed camera video can be started and will record remotely at any time.
In addition to the STIV technology, ES is also investing is several web camera sites.
The two projects will share some of the same infrastructure at the monitoring sites.
The network of web cameras will allow images to be captured from multiple viewpoints, allowing for easy access to information like weather conditions, snow cover, water clarity and river flow, as well as site risks.
ES is establishing three other sites, the Waihōpai Dam in Invercargill, Mataura River at Gore and the Oreti River at Three Kings, to join their first pilot study site at the Oreti River at Lumsden.