Water quality sensors

In-situ sensing for AquaWatch refers to using sensors in or just above the water to measure water quality parameters, for example identifying cyanobacteria in the water.

In-situ sensing is important for AquaWatch because, though it can only look at a small area of water, it gives us highly accurate readings that can be used to validate what we’re seeing from space with remote sensing. When the two data sets are combined, we can aim for both accuracy and broad scope.

Comprehensive monitoring:

• Water-based sensors (in-situ sensors) are deployed directly into water bodies, providing real-time data on various water quality parameters such as temperature, pH, dissolved oxygen, turbidity, salinity and nutrient levels.
• By integrating water-based sensors into the AquaWatch network, we achieve comprehensive coverage across inland rivers, waterways and coastal environments.

Accuracy and precision:

• These sensors offer high accuracy because they measure conditions directly at the source and provide precise local measurements. The highly accurate data can be used to validate the broader coverage from satellite data.

HydraSpectra sensor

One type of water quality sensor deployed for the AquaWatch in-situ sensor network is CSIRO’s HydraSpectra sensor, a low-cost optical system for field-deployed water quality monitoring based on spectral reflectance.

The HydraSpectra is an optical sensor developed by CSIRO and a key technological component of the AquaWatch system. It offers our users a solution to enhance the efficiency and accuracy of water quality monitoring, water compliance and risk assessment across geographically dispersed sites.

Hydraspectra features:

• Low cost and robust for accessibility and uptake
• Sits above the water surface, reducing the need for frequent maintenance.
• Simultaneously captures water reflectance and surface photos at 15-minute intervals, offering continuous monitoring capabilities.
• Data enables determination of algal pigment/biomass concentrations and sediment levels in surface waters.
• Facilitates tracking of algal bloom or sediment plume formation and dissipation.
• Integration with hydrodynamic modelling and prediction enhances the utility of this information.
• Deployed as a network of sensors and coupled with satellite imaging technologies, the instrument is part of a system-wide overview of potential blooms, as well as assessing of individual water body dynamics.