Nature and aquatic environmentSustainability

Industrial PhD on the future of water quality monitoring


Cooperation between Aarhus University, Hach and Envidan


Industrial PhD on monitoring water quality in Danish watercourses





Monitoring water quality in Danish watercourses

Hydrogeologist Sofie van’t Veen is well underway with her 3-year PhD project, SENTEM (Sensors Application for High Temporal Resolution Monitoring in Danish Streams) in collaboration with Aarhus University (Department of Ecoscience), Hach and Envidan.

The aim of the project is to generate new ideas and knowledge about the future use of sensor data with high temporal resolution, among other things by using Machine Learning for next generation monitoring of water quality in Danish watercourses.

Through the project, Sofie will test sensors, develop methods for quality assurance of data, set up measurement campaigns in relation to rainfall-runoff and contributions from the open countryside, etc.

Much more certainty by measuring every minute

Today, nutrient levels in Danish watercourses are usually measured manually every month and in a few cases every 14 days. However, the relatively small number of measurements means a high degree of uncertainty. This is why the project is highly relevant, as we are likely to see a future where the use of sensors measuring values every minute will become commonplace. Moreover, the current method is a hand-carried process that costs Danish society approximately DKK 30 million per year. This means that, in addition to much more accurate measurements, there is also a lot of money to be saved by implementing a new generation of monitoring.

The use of sensors for monitoring is widespread in wastewater treatment plants, but not yet in watercourses. The project is part of Envidan’s R&D investment, thus supporting research and development that builds on Envidan’s competencies within the water cycle.

Benefits of online high-frequency data

Possible values to obtain from online high-frequency data at monitoring stations in watercourses could be to

  • Gain knowledge about the accuracy of calculating nitrogen and phosphorus transport (compared to normal point samples – what is gained in terms of bias and dispersion) – e.g. for use in annual national marine load assessments
  • Gain experience with the resource consumption of online measurements and sensors in relation to Care, calibration and data management
  • Gain new knowledge about sources of N and especially P, including knowledge about retention and transport pathways
  • Achieve faster and more reliable trend determination at a given level
  • Gain better knowledge of N and P retention in catchments

The five objectives

  1. To develop an innovative methodology and guide for the use, quality assurance, calibration, and validation of high temporal resolution data for sensor monitoring in different types of Danish watercourses by means of a methodology and guide for the use, quality assurance, calibration and validation of high temporal resolution data for sensor monitoring in different types of Danish watercourses. Machine Learning

  2. Establish in-depth knowledge of the importance of high temporal resolution data for calculating nutrient loads at daily, monthly, and annual time steps
  3. To investigate whether nutrient sources and pathways in catchments can be identified using high-temporal-resolution data
  4. To investigate trade-offs between high temporal resolution data when calibrating a SWAT model to improve the model under extreme climate conditions
  5. To investigate whether overflows of untreated wastewater and/or sources such as surface runoff into streams during storm events can be detected and quantified using high-resolution sensor data, radar observation of precipitation, and Machine Learning

Do you need help?

From nature restoration to river restoration and maintenance – we have a strong team of experts to help and guide you.

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for more information

Sofie Gyritia Madsen van’t Veen


+45 28 25 75 78

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