Scoop has an Ethical Paywall
Groundwater Drives Rapid Erosion Of The Canterbury Coastline
Groundwater flow and seepage can form large gullies along coastal cliffs in the matter of days, it has been discovered, as per a recently-published paper.
An international team of scientists from Malta, Germany, Romania, New Zealand and USA has used drones and satellite imagery to monitor a stretch of coastline near Ashburton (South Island, New Zealand). They found that gullies up to 30m in length can develop in less than a week.
Field observations and numerical models have shown that groundwater plays a key role in forming these gullies, by either eroding tunnels or triggering landslides.
Gullies are an important coastal hazard. There is an average of one gully every 250m along the Canterbury coastline, and their formation leads to the loss of precious agricultural land.
Similar coastal gullies have been documented in South Taranaki (North Island, New Zealand), as well as other countries such as the USA, Japan and Brazil.
When and where coastal gullies form can be partly predicted. The study has shown that gullies form when more than 40mm of rain fall per day, and that they are preferentially located above buried, old river channels.
This study was led by Prof. Aaron Micallef from the Department of Geosciences, and is an outcome of the MARCAN project, which is funded by the European Research Council.
Business Canterbury: Urges Council To Cut Costs, Not Ambition For City
Wellington Airport: On Track For Net Zero Emissions By 2028
Landcare Research: ANZAC Gall Fly Release Promises Natural Solution To Weed Threat
NZ Anti-Vivisection Society: Auckland Rat Lovers Unite!
University of Canterbury: $1.35 Million Grant To Study Lion-like Jumping Spiders
Federated Farmers: Government Ends War On Farming
