Acoustic Doppler Devices and Number Nuances

Phil Hook

Do you have hydrometric stations with complex hydrology? Issues with reverse flow and tidal water levels affecting your stage/discharge relationships? PDP may have the solution for you!

Acoustic Doppler Profilers (ADPs) are becoming increasingly utilised in remote environmental monitoring situations to enable stakeholders to understand complex flow relationships in real time. Pattle Delamore Partners (PDP) have installed and operated ADPs in a large monitoring network (covering a catchment area of 48,900ha) which includes complicated stage-flow relationships.

These monitoring locations, where loop ratings (Hysteresis) would have previously been used to understand the stage-discharge relationship, are now able to be accurately measured using ADP technology.

Hysteresis is complex and requires large amounts of time and therefore expense to determine an accurate stage/discharge rating,

Advantages of using ADPs include:

  • Flow ratings can be used for other determining other relationships such as sediment flux;

  • ADP automatically calculates the flow rate, which can be telemetered back to user providing real time data;

  • Reduced amount of time needed to develop a rating for the monitoring location

  • Can be a more cost-effective solution

  • If calibrated to gaugings and operated correctly, velocity indexing can be accurate to within 1%.

There are also a few disadvantages show that this technology is not always fit for purpose i.e. in areas with particularly weedy rivers.

This presentation will discuss in more detail a Whangamarino case study, detailing the advantages and disadvantages of using this technology and how this technology was used to provide real time sediment flux movement.