Leuven, 31 July 2024
Citizen Science Weather Stations Network in Leuven, Belgium
In Summary: promote Citizen Science to democratize environmental policies
Changing climate is set to increase the frequency and intensity of extreme weather. Urban areas are considerably more vulnerable due to rapid increase in populations and high built-up areas. It is therefore necessary to investigate the heterogenous urban climate, and for this, high quality atmospheric measurements are necessary. Studies have shown that canopy air temperature is more closely related to human health and comfort.
The rise of crowdsourced air temperature data, especially in urban areas, could be a promising solution to bridge this knowledge gap. However, due to their nontraditional measuring equipment and installation settings, the quality of datasets from these networks remains an issue. Quality uncertainty arises due to several issues: (1) calibration issues in which the sensor could be biased either before the installation or due to drift over time, (2) design flaws in which the design of the station makes it susceptible to inaccurate observations, (3) communication and software errors leading to incorrect or missing data, (4) incomplete metadata, and (5) unsuitable installation locations.
The city of Leuven has set up a large local sensor network in collaboration with residents, Leuven2030, KU Leuven (sensors in the private gardens, data storage and visualization, modelling and scientific research), RMI (calibration and calibration device). The project seeks to provide data that will contribute in the studying of the relationship between blue-green infrastructures in reducing the heat-island effect in the city.
The Leuven.cool network is a uniform network of around 100 weather stations of type Fine Offset WH2600, installed in both private gardens and at (semi-)public locations to measure microclimate in Leuven. This local sensor network measures temperature, humidity, UV radiation, windspeed and rain.
The WH2600 wireless digital weather station outdoor unit
The weather stations were installed according to a strict protocol. In private gardens, the weather stations were installed at 2 m height using a steel pole with a length of 2.70 m. Dry concrete was used to anchor the pole into the soil at a depth of 70 cm. Following the station's guidelines, stations were installed in an open location within the garden, at least 1 m from interfering objects, such as nearby buildings and trees. In order to maximize the absorption of solar radiation by the solar panel and to ensure correct measurements of wind direction and precipitation, the weather station was levelled horizontally and the solar panel of the weather station was directed towards the south. Weather stations located on public impervious surfaces were installed on available light poles using specially designed L-structures to avoid direct contact with the pole. For security reasons, an installation height between 3 and 4 m was used.
Scientific researchers from KU Leuven have developed a novel quality control method for the particular sensor type used in these weather stations, which removes implausible measurements, while also correcting for inter-station (between-station) and intra-station (station-specific) temperature biases.
Citizen participation is very integral in the collection of this data. More than 60 participants volunteered their gardens to set up a weather station and contribute to its maintenance by keeping an eye out for generic problems. The rest of the weather stations are installed in the public domain.
The Leuven.cool network installation within Leuven's Local Climate Zones (LCZ)**
In USAGE, the data is useful to identify hot spots in the city and identifying priority areas for greening interventions such as identifying locations for extensive green roof installations, areas that can be unsealed and replaced with green areas etc.
This article contains excerpts from_: Beele, E., Reyniers, M., Aerts, R., and Somers, B.: Quality control and correction method for air temperature data from a citizen science weather station network in Leuven, Belgium , Earth Syst. Sci. Data, 14, 4681–4717, https://doi.org/10.5194/essd-14-4681-2022, 2022.