Oral Presentation Australian Society for Limnology Conference 2017

Critical evaluation of smartphone apps as tools for water quality monitoring in SEQ inland waters (#100)

Tim Malthus 1 , Renee Ohmsen 1 , Stephen Gensemer 2 , Janet Anstee 3 , Stuart Phinn 4
  1. CSIRO Oceans and Atmosphere Flagship, Dutton Park, QLD, Australia
  2. CSIRO Manufacturing, Brisbane, QLD, Australia
  3. CSIRO Oceans and Atmosphere, Canberra, ACT, Australia
  4. School of Earth and Environmental Sciences, University of Queensland, Brisbane, QLD, Australia

Tools are required to assist water managers to support under-resourced in situ water quality monitoring programs. Citizen science is one solution to obtain data over wider areas, more often. Smartphone apps may provide a useful complement to traditional methods if reliable. Two such apps are EyeOnWater and Hydrocolor.  

EyeOnWater (http://www.eyeonwater.org) evaluates water colour using the Forel-Ule (FU) scale, a 21 level scale used to measure the colour of natural water bodies. Users take a horizontal photo of the water surface and match the water colour recorded to the FU scale. The result is uploaded to an international database of measurements.

Hydrocolor (http://misclab.umeoce.maine.edu/research/HydroColor.php) uses an iPhone camera to measure surface reflectance. Users deploy a photographer’s grey card and separately take images of the card, the sky and water surface at observation angles guided by the app. Using the three images, HydroColor calculates water body reflectance in the RGB colour channels and uses these to determine water turbidity in NTU based on relationships for North American waterbodies.

We evaluated app performance using replicated measurements made in 13 reservoirs across SEQ and NSW covering a range of water qualities (Chl a from 2.5 to 180 mg.m-3). The presentation will report on the performance and utility of the apps in comparison to separate determinations of high spectral resolution reflectance made using a Satlantic underwater spectroradiometer and water quality parameters measured from concurrent sampling. The value of such approaches for informing on water quality will also be highlighted using SEQ examples.