The Critical Role of Monitoring

The Critical Role of Monitoring

Interview with Burcu Zijlstra, R&D Engineer at imec the Netherlands

Burcu Zijlstra is an air quality project lead at OnePlanet Research Centre. With a master’s degree in materials science and engineering from the Swiss Federal Institute of Technology Lausanne, she has worked in R&D of air quality sensors in Switzerland and the Netherlands for several years. In this interview, she explains the ongoing monitoring work in LIFE CRITICAL.

Could you tell us a bit of background about yourself, imec and OnePlanet?

In 2020 I joined OnePlanet, which is a unique collaboration that combines imec’s unique expertise on digital technologies with the domain expertise of supporting universities to develop solutions in health, agriculture-food and environmental sensing. Our environmental sensing team at OnePlanet focuses on several topics: developing novel sensor technologies, integrating sensors into fine-grid measurement networks and real-time deployable sensor calibration algorithms to improve data quality from low-cost sensors.

OnePlanet was founded in 2019 when nitrogen emissions were becoming a hot topic in the Netherlands and there was a growing understanding that sparsely distributed high-end measurement stations give an incomplete picture of emission sources. Therefore, our environmental sensing team has a strong focus on monitoring nitrogen compounds, which are not only harmful to human health, but their deposition in nature also negatively impacts ecological balance and biodiversity.

What is imec’s role in LIFE CRITICAL?

In LIFE CRITICAL, imec leads the sensor deployment and monitoring efforts in Dordrecht’s Wielwijk Park and quantifies the effects of urban transformation in the area using sensor data. At the start of the project, we identified measurable parameters related to climate-resilience in the neighborhood, then validated and deployed the sensors.

One pollutant of interest, NO2, did not have commercially available integrated sensors that fit our needs, so our team developed a solar-powered sensor prototype to fill the gap. Now that the sensors are deployed, we monitor the effects of urban transformation using sensor data, as well as sensor performance and data quality.

What value does data monitoring add to climate adaptation measures?

Since climate conditions are not static, quantification of climate adaptation is only possible through comparing the local climate conditions (which are changing due to urban transformation) to a reference, which can be a fixed reference sensor. Data monitoring can also help address specific questions – for example the density and type of trees we should plant to help decrease summer peak temperatures by 3°C. This kind of knowledge can then be passed on to future projects.

How do citizen science sensors strengthen LIFE CRITICAL’s work?

Urban transformation encourages citizens to take advantage of the benefits that come from improvements in public spaces. Involving citizen science sensors is an extension of this, where we help provide citizens with tools to quantify the climate resilience of their day-to-day spaces. This allows them to concretise their concerns into questions and be a part of the discovery process, motivating them to actively improve their own spaces and neighbourhoods. A bonus benefit is that performing a small field study is truly fun, and this engagement builds trust between all parties and builds citizens’ interest in science!

What is the importance of sharing sensor data on a public platform accessible by all citizens?

Sharing sensor data with citizens lays the groundwork for citizen engagement. It increases transparency between the municipality and locals so they can benefit from each other and improve their common way of working. Citizens also interact more frequently with the area in which the sensors are deployed and can give feedback to technical partners that helps to interpret the observed data.

How does monitoring facilitate replication of LIFE CRITICAL in other urban parks?

Every region has its own challenges related to the local air quality and climate, so the urban transformation would not be a 1-1 replicate. However, if we break down a region’s concerns into questions and measures taken to reduce the concerns, monitoring allows us to pinpoint which measures are effective and to quantify their effectiveness.

In the time since deploying sensors around Wielwijk (1.5 years for microclimate and 1 year for air quality), have you noticed any improvements as a result of climate adaptation measures?

Baseline monitoring that we performed with the sensors already shows us that in the summer of 2021, there was an average daytime temperature difference of +1°C and relative humidity difference of -6% in between the urban and park areas, and on the warmest summer day the peak temperature in an urban area was 4.7°C warmer than the park area. When we look at NO2 pollutant concentrations, we see an average increase of 33% between the residential and park areas, and up to 66% increase in the highway-adjacent roads. As the first stages of the renovations are finalised, we are curious to see the effects of the climate adaptation measures and learn whether the mild microclimate, low pollution areas are expanded as a result.

As more data is gathered from these sensors, are there any trends you expect to see?

Urban areas suffer from an urban heat island effect. Due to heat retention from infrastructure and higher NO2 concentrations from traffic, urban areas are hotter and have lower relative humidity. We expect that as blue-green spaces are expanded around Wielwijk Park, sensors will reveal decreased peak temperatures and higher humidity in summer, leading to a better experience for citizens who use the park. We also expect a drop in NO2 concentration as a result of decreased road traffic in the area, and a further reduction if the pollutant is absorbed by the green canopy.

Are the measurements you currently monitor sufficient, or would you like to expand it? What else would be valuable to measure and why? What other approaches to using this data do you foresee as the project continues?

To quantify the impacts of climate resilience measures, we need to compare sensor data pre- and post- urban transformation. So, for the Wielwijk region, we prefer to maintain our current monitoring measures. Renovations in Bradford’s Horton Park have not yet started, so exploring different monitoring sensors is on the table. There is a multitude of sensors and environmental parameters that could be measured, but we want to focus on the unique use case of this area. Ultimately, we will choose these sensors by their relevance to the climate resilience measures targeted by the renovation, the sensor unit requirements (e.g. power, connectivity), and the accuracy and long-term reliability.

What lessons from Wielwijk Park will you replicate in Horton Park?

Whereas long-term performance of temperature-humidity sensors is well-characterised, monitoring NO2 with low-cost sensors is a challenge. It is best when sensors, which are cross-sensitive to their environment, are continuously evaluated. In this project, we deployed NO2 sensor prototypes next to monitoring stations simultaneously with the field deployment in Wielwijk to evaluate sensor performance under current climate conditions. This is something we want to replicate in Horton Park as well.

We also find that good communication between the municipality and technical partner is key. This is forms a foundation to help pinpoint the research questions related to quantification of climate resilience, which can be addressed by the data monitoring analysis.

What’s the next step for imec in LIFE CRITICAL?

We will keep close track of the urban transformation in Wielwijk to refine the research questions we seek to answer with the collected data. Additionally, we will support the municipality of Bradford in sensor deployment to monitor their urban transformation plans. At the same time, we will continue developing and improving the OnePlanet nitrogen compound sensor network and calibration algorithm. We also plan to support municipality of Dordrecht in their citizen science campaign so that citizens can take charge in addressing their questions about climate resilience.