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Description
The town of Velká Bystřice is located at the very "end" of the Moravian Gate. It is influenced by the nearby city of Olomouc and frequented transport route from the City of Ostrava, thus, its air quality is unstable and fluctuates greatly. Therefore, the town has decided, in cooperation with the region of Olomouc, to secure air monitoring using the AIM station (in operation from the beginning of 2023). Velká Bystřice is a typical town where massive natural gasification took place in previous years, but the residents are returning to traditional solid fuels. The station is a reference standard for air quality and its integration within the framework of proposed sensor network would significantly expand the impact of measurements and enable individual the town to better adress and influence its citizens in regard of air quality.
Through the course of the project, 15 places in the area will be measured, including areas with local heating plants and mixed zones with eco-heating. All data will be transmitted to a MYSQL database and displayed as points, surfaces, and graphs. The data will be exportable for further processing. Each location will have a card created (location, description, photo), and the system will store information on sensors – e.g. validation factors (on start and interim). The operation and data quality will be ensured by the VŠB TUO. Parallel measurements with AIM station will be used for sliding control of sensors.
Summary of project results
The project aimed to acquire, operate, and evaluate sensor measuring technology. The main objective was to verify the suitability of sensor technology for measuring air quality in municipalities, particularly concerning local heating. A fundamental problem is the growing popularity of using sensors to measure practically anything, including air quality, without basic responsibility for measurement quality. The market is literally flooded with sensors without laboratory validation. However, municipalities are part of public administration and need air quality measurements for their citizens. The results serve to implement measures such as boiler replacement, traffic optimization, or interventions in industry. Therefore, responsible measurement approaches are needed. In the project, a database was prepared for further use by the Czech Hydrometeorological Institute (CHMI) and for transferring experiences to other projects. The database is native, meaning it contains all the events that have occurred on the sensors, such as outages, extremes, high or low sensitivity, and so on. This is to understand the correct selection and ensure responsible sensor operation. At the same time, the project found that municipalities are very heterogeneous areas and air pollution by PMx is uneven. It could be due to local influences or sensor errors, which will need further monitoring in the data. However, the project brings additional extensive experience, according to which measurement quality can be reasonably adjusted. The measurement also demonstrated that sensors cannot replace reference measurements, which are far more robust and under continuoust supervision. However, Spatial data from sensors can be used for interpretations even with all reservations
The sensors were procured from a supplier as part of a public tender, with the basic requirement for their delivery being calibration before the start of measurement. Calibration took place at the Czech Hydrometeorological Institute (CHMI), simultaneously for all sensors with the reference dust monitor ENVEA. The measurement lasted for 40 days, and its output is a validation protocol. Before the heating season, the selection of monitoring sites took place, totaling 15 across the entire length of the municipality. The placement of sensors proceeded gradually, putting them in their respektive locations before temperature dropped and the heating season actually started. Validated sensors were continuously monitored by the staff, and the data were transmitted online to the Smartenvi.eu web server. The data file was handed over to CHMI for further use in an agreed format, and is described in the Final Project Report. The leadership of the involved municipalities used the results for regular citizen updates and anticipates further use in sustainability. The creation of a database is a significant contribution to air protection, which can help in the future with data autovalidation, sensor self-monitoring, and advanced interpretation. It is already clear that sensors can be used to understand emission/immission dynamics in the municipality and can be a valuable auxiliary tool in air quality protection. This need will increase with the pressure from the European Union to tighten limits from 2030 onwards.
The main output is a supervised database, which will further serve for sensor settings as auxiliary measuring devices. The measurements also demonstrated that the advantage of sensors is their deployment in a networks, with sensors correlating very well and their measurements being acceptably accurate. The problem remains with the correctness of the measured values compared to reference methods. The project results indicate that sensor measurements are indicative in relation to limits and sensors need to be continuously monitored. At the same time, the situation in the area is very well described, whether there are any local sources of air pollution in the municipality - such as the burning of poor-quality fuels. The city is very interested in measurement as an educational tool and for communication with citizens. Municipal leaders intend to invest in air protection measures in the future, if possible, and continuous measurement will help them selectively choose and monitor measures. Average PM10 concentrations in the heating season often exceed the annual limit of 40 µg/m3, with the worst-hit areas being Loučná, Havlíčkova, Nad Skalou, where average PM10 concentrations exceed 50 µg/m3. The maximum concentration was measured in the Loučná locality, reaching 300 µg/m3. However, high concentrations were also found in other areas. Reference stations measure significantly lower maximum concentrations, and it can be assumed that sensors tend to overestimate in high values. Sensors correlate with each other in the range of 0.8 - 1.0, indicating that the network is consistent. Sensor measurement yield exceeds 90% in most cases.
Air quality remains a fundamental issue for our citizens, which is why public administration focuses on its protection. The Local Sensor Network project in Velká Bystřice aimed at continuous monitoring of suspended particles PM10 and PM2.5. Municipalities generally know they need to address dustiness, but despite their knowledge of their territory, they cannot even identify the biggest culprits. In combination with the AIRP''S project (TROMSO), the measurements are one of the outputs of Action Plans and support sensible activities in the locality - from green care and road cleaning to transportation infrastructure or energy. Action Plans serve as a repository of possible measures, but they need continuous monitoring. Given the EU deadlines in the Green Deal policy, the year 2030 is very close, and significant changes in legislation regarding air protection will occur this year. If municipalities are not prepared, it will be very difficult to achieve changes that have a positive impact on health. Conversely, it is unfortunate that the entire public administration is not systematically addressed, as problems can arise even in areas that currently appear to be in good condition. There are significant differences between sensors, although the correlations within the network are excellent, alignment with the reference method is no longer straightforward. The degree of tightness ranges from minimal to significant, and this difference may be due to the location or the sensor itself. Validation checks were carried out during the project implementation, and subsequent changes to the validation factor, yet there were no significant changes in the measured concentrations of PMx. Sensors exhibit a similar trend to reference measurements but are differently "sensitive"; they also often have more significant deviations, i.e., randomly outlying points that would be advisable to remove from the results. The presented database is unaltered, due to the project''s goal = to understand the proper functioning of sensors and define how to use them.