Taking to the sky to better understand our water
Ever wondered what lies beneath the earth’s surface? Aerial Electromagnetic surveys search for water from the air, helping us identify and characterise local groundwater resources.
If you’re a resident in WA’s Great Southern or recently visited the region, you may have spotted a large round object hovering in the sky.
As part of our ongoing commitment to better understand and improve the use of our critical groundwater resources, we conducted an Aerial Electromagnetic (AEM) survey in Albany over the course of 6 days.
The survey was completed by a helicopter flying at about 70 metres altitude, towing a large loop at 35 metres above ground to measure the conductive properties of the ground.
Having completed an AEM survey in Exmouth earlier this year, these surveys are becoming an increasingly used tool for understanding water salinity variations within a groundwater resource.
New Resolution Geophysics AEM system maps the groundwater in Albany.
How does it work?
The AEM survey is designed to characterise water and rock conductivity by using an electromagnetic field. The electro magnetic field is transmitted from the loop towards the ground. If conductive bodies like saline water, mineralised rocks or clay rich formations are present in the ground a secondary field is produced and picked up by a receiver in the centre of the loop.
The data is then processed and converted into an electrical conductivity and depth profile. The results help us understand the extent of the fresh groundwater resource that is suitable for water supply.
Continuously improving the understanding of our groundwater systems enables us to make the most informed decisions around our ongoing abstraction strategy and future source planning.
Is it safe?
The health and safety of the communities we service is extremely important to us.
No harm is caused to plants, animals or humans from the electromagnetic loop. The EM fields emitted by the loop are similar in amplitude to those produced by power lines. The height and speed of the helicopter will limit any exposure to anyone on the ground.