Deltares has developed a Water Quality App for smartphones to enable citizens to measure and share water quality measurements. The project’s aim is to enable farmers to participate in the collection of water quality measurements in order to establish the relationship between different agricultural practices and water quality. This requires a method that allows participating farmers to both collect measurements and share this information easily. We hope to achieve this by collecting water quality data by using test strips and sending the results via smartphone.
Goals
- Enable farmers and other citizens to measure and share water quality measurements
- Collect water quality data by using test strips and a smartphone
- Establish the relationship between different agricultural practices and water quality
Why use the Water Quality App?
Using a smartphone to read test strip measurements is a new opportunity that is well suited to allow farmers to collect data. Test strips are widely used to get an indication of water quality and are available for a variety of relevant parameters, such as nitrate, nitrite, ammonium, phosphate, sulphate, chloride, and pH. The strips are submerged in water for a few seconds and the measured value can be determined by comparing the color of the strip against a legend. There are many benefits of using test strips compared to other methods, such as lab analyses or chemical test kits: test strips are easy to use, the speed of measurements is relatively quick (e.g. 1 minute for nitrate), the measurement result is readily available, and there is a low cost per measurement. Disadvantages of using test strips are their limited accuracy (especially at low concentrations) and the subjective way of measuring concentrations using the naked eye. Reading the test strips with a smartphone has numerous advantages: smartphones can read measurements accurately and objectively, and the results can be sent directly to a database and/or online platform. Measurements can be viewed immediately and compared to the local context (other measurements, standards, or study area characteristics).
Deltares has developed the Water Quality App to allow the test strips to be read quickly and efficiently. The test strips are placed on a card with a color legend (the same size as a bank card) and photographed through the app. The app uses image processing software to compare the color of the test strip against the legend. Since the strip and legend are side by side in the picture, errors due to variations in light, phone type or picture settings are expected to be minimal. The app then displays the measurement and the user has the option to send the result. If the user agrees, the measurement, along with metadata (time, location), are sent over the Internet to a server. If an Internet connection is not available, the data is prepared and is automatically sent when the phone is connected to Wi-Fi. Once on the server, measurements can be verified, visualized, edited, etc. This method can easily be applied to other parameters or types of test strips.
Getting started
To collect water quality measurements, you need the following:
- Jar with test strips (for nitrate, use Hach test strips: http://www.hach.com/nitrate-and-nitrite-test-strips/product?id=7640211606)
- Deltares legend card
- Cup
- Smartphone with Water Quality App
Check out our tips and tricks to get started!
Results
Results are visualized within the Delta Data Viewer. This web-based viewer is easy to use and suitable for desktops, tablets, and smartphones. The flexible design makes it easy to develop specific views for certain catchment areas and/or user groups. The data can be visualized in different ways and the user can choose between different background maps. All Deltares software, apps and viewers are open and free to download and use.
FAQs
Below is a list of frequently asked questions and their answer:
| Question | Answer |
|---|---|
| None yet - be the first to ask a question in the comments below! |
Additional information
Want more information? Contact Joachim Rozemeijer (Joachim.Rozemeijer@Deltares.nl) or Sheila Ball (Sheila.Ball@Deltares.nl). You can also download the information sheet about the Nitrate App (predecessor of the Water Quality App).
