City Of Thessaloniki Research Articles

Exploring patterns of surface urban heat island intensity: a comparative analysis of three Greek urban areas

One of the most pressing issues of our time is the destabilization of the global climate as a result of rapid urbanization. In Europe, according to United Nations reports, almost 73% of the population lives in cities and this percentage is expected to rise to 85% by 2050 (United Nations and Department of Economic and Social Affairs, ‘World Urbanization Prospects 2018 Highlights’, 2018). This observed urban development and its trends pose significant challenges to our urban environments, therefore it is critical to improve our understanding and assess its impact by measuring and analyzing its patterns. This study presents a comprehensive five-year analysis of microclimatic parameters that can contribute to this analysis, such as land surface temperature (LST) and surface urban heat island (SUHI) intensity, using remotely sensed data over three cities in Greece. Specifically, the selected cities are the city of Thessaloniki, which is the second largest city situated in the northern part of Greece, the city of Larissa on the mainland, and finally the city of Tripoli in the Peloponnese peninsula in southern Greece. Each city represents urban areas with different physical and urban characteristics. For this purpose, the vegetation index-based technique for LST extraction was applied within the Google Earth Engine (GEE) platform. Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) calculations were also performed over a five-year period. The results highlighted the spatio-temporal variations and trends that occur in the studied urban areas, providing valuable insights into the annual patterns of the SUHI phenomenon in different geographical contexts within Greece. This is particularly relevant in countries like Greece, where the density of World Meteorological Organization (WMO) stations providing reliable temperature data is low, usually limited to one per city. Consequently, LST derived from satellite data can provide more accurate intra-urban results of the SUHI effect, demonstrating the value of remotely sensed data as a cost effective and supportive tool for decision-making in environmental and urban planning policies.

Effect of SARS-CoV-2 shedding rate distribution of individuals during their disease days on the estimation of the number of infected people. Application of wastewater-based epidemiology to the city of Thessaloniki, Greece

During the COVID-19 pandemic, wastewater-based epidemiology has proved to be an important tool for monitoring the spread of a disease in a population. Indeed, wastewater surveillance was successfully used as a complementary approach to support public health monitoring schemes and decision-making policies. An essential feature for the estimation of a disease transmission using wastewater data is the distribution of viral shedding rate of individuals in their personal human wastes as a function of the days of their infection. Several candidate shapes for this function have been proposed in literature for SARS-CoV-2. The purpose of the present work is to explore the proposed function shapes and examine their significance on analyzing wastewater SARS-CoV-2 shedding rate data. For this purpose, a simple model is employed applying to medical surveillance and wastewater data of the city of Thessaloniki during a period of Omicron variant domination in 2022. The distribution shapes are normalized with respect to the total virus shedding and then their basic features are investigated. Detailed analysis reveals that the main parameter determining the results of the model is the difference between the day of maximum shedding rate and the day of infection reporting. Since the latter is not part of the distribution shape, the major feature of the distribution affecting the estimation of the number of infected people is the day of maximum shedding rate with respect to the initial infection day. On the contrary, the duration of shedding (total number of disease days) as well as the exact shape of the distribution are by far less important. The incorporation of such wastewater surveillance models in conventional epidemiological models - based on recorded disease transmission data- may improve predictions for disease spread during outbreaks.

Determinants of the travel satisfaction of e-scooter users

This paper seeks to fill in the current evidence gap on the relationship between travel satisfaction and e-scooter use. To do so, online survey data from e-scooter users of a University community in the city of Thessaloniki, Greece were collected and statistically analyzed. In line with previous research on travel satisfaction, the results of a series of exploratory and confirmatory factor analyses unveiled the potential of factors surrounding positive activation, positive deactivation, and cognitive evaluation to serve as key determinants of satisfaction of e-scooter riders. Furthermore, a structural equation model (SEM) was estimated to identify the impact of user- and trip-related characteristics on travel satisfaction. The results of the SEM showed that older and high-income riders, those with good self-reported physical condition, riders of private e-scooters and leisure travelers are more likely to perceive greater satisfaction by the use of their e-scooters. The findings of this study overall contribute to the current state-of-knowledge relating to travel satisfaction and pave the way for potential policy actions that could improve users’ experience with e-scooters and enhance the overall attractiveness of micromobility in the pathway towards sustainable and inclusive mobility.

Exploring Community Readiness to Adopt Mobility as a Service (MaaS) Scheme in the City of Thessaloniki

Mobility as a Service (MaaS) is a new mobility solution that brings together different modes of transportation, such as car-sharing, public transport, taxis, and bicycles, to create personalized service packages for commuters. The present study aims to identify key factors affecting the adoption of a Mobility as a Service system, and to explore the extent to which a local community is ready to accept the implementation of MaaS. The case study investigates the city of Thessaloniki, which is the second largest urban agglomeration in Greece. This study applies a triangulation approach by combining quantitative and qualitative analysis, providing a comprehensive understanding of the opportunities and the challenges arising with the implementation of a MaaS system in the city of Thessaloniki. Furthermore, the utilization of MaaS as a tool for vulnerable people, a crucial aspect that has not been analyzed properly in the existing literature, is examined. A quantitative survey analysis was conducted, inferential statistics were applied, and a binary logistic regression model was developed to determine the significant characteristics that most affect citizens’ willingness to use a MaaS system. In addition, stakeholders were interviewed to examine their readiness to promote and collaborate for the development of a MaaS system. Results showed that age, driving license, daily time spent on urban trips, the frequency of commuting as car passenger or by public transport (PT), previous usage of a MaaS system, and the number of family members seem to be the most influential factors of citizens’ choice to adopt MaaS. For stakeholders, the quality of service provided, and the user friendliness of the system are necessary prerequisites. The findings reveal that the views of residents and stakeholders provide some positive foundations for the development of a MaaS system in the city.

Trade Fairs, Host Cities and Tourism Development: The Case of Thessaloniki, Greece

The literature has mainly focused on the significant business opportunities that companies obtain from their participation in trade fairs while less interest has been given to their impacts on the host regions. However, trade fairs are events with complex socio-spatial dimensions and an important scope of urban governance that need further analysis. The purpose of this article is to investigate the attitudes, opinions and representations of the exhibitors and visitors of the trade fairs in Thessaloniki, regarding the trade fair itself and its efficiency, the city of Thessaloniki as a destination, as well as the relationship between trade fairs and the city. The method of collecting qualitative material and information involved in-depth interviews with a semi-structured interview guide, while quota sampling was used. In total, 103 interviews were conducted at the trade fairs of Zootechnia and Detrop. Results show that the effect of trade fair activity on the city of Thessaloniki is strong and multi-layered. Also, the relationship between trade fair activity and the city is interactive and two-way, as one feeds and is powered by the other. Moreover, the need for coordination and cooperation between local agencies in an urban governance framework was highlighted.

Historical Evolution of Trade Fairs against Urban Evolution: Divergence and Convergence of Thessaloniki Fair with International Practice

This paper conceptualizes trade fairs as complex socio-spatial phenomena, which are constantly transformed, following socio-economic change, and reflect aspects of social and urban life. Methodologically, we apply a longitudinal systematic comparative analysis of historical fair evolution between international practice and the case of the city of Thessaloniki, exploring convergence and divergence, throughout the historical evolution of the city. It is shown that Thessaloniki fair exhibits similarities and differences vis-à-vis the international practice, with these linking to the socio-economic conditions of the city. Fair activity in Thessaloniki exhibits a time lag in integration of international practices while incorporating economic, social, cultural, and political dimensions. Particularly within the conditions of the 2008 global economic crisis, Thessaloniki fair emerges as a hybrid model that combines fairs’ strategies and social and urban practices with aspects of pre-modern, modern, and post-modern fair forms, significantly influenced by the historical evolution of the urban context.

The Attitudes of Patients with Cardiovascular Diseases towards Online Exercise with the Mobile Monitoring of Their Health-Related Vital Signs.

The health care cost of cardiovascular diseases (CVD) in the EU is estimated to be today over 282 billion euros. It is well documented today that exercise training is one of the main strategies for secondary disease prevention and the follow-up integration of these patients. This study aimed to examine patients' attitudes towards online exercise with mobile monitoring of their vital signs. More specifically, the research objectives were as follows: (a) to examine patients' attitudes and expectations of online exercise, (b) cluster patients in high- and low-attitude groups and examine their intention to participate in online exercise, and (c) to examine age and gender differences in terms of their intention to exercise online. The final goal of this project was to develop a real application that could be of use to patients and professionals. Data were collected from fifty patients in the city of Thessaloniki, Greece. The results revealed that most patients were positive about exercising online if the programs were perceived as fun and, especially, safe. The use of an online monitoring application with the distant supervision of health professionals could both motivate them and strengthen their feeling of safety.

Assessing Impact Factors That Affect School Mobility Utilizing a Machine Learning Approach

The analysis and modeling of parameters influencing parents’ decisions regarding school travel mode choice have perennially been a subject of interest. Concurrently, the evolution of artificial intelligence (AI) can effectively contribute to generating reliable predictions across various topics. This paper begins with a comprehensive literature review on classical models for predicting school travel mode choice, as well as the diverse applications of AI methods, with a particular focus on transportation. Building upon a published questionnaire survey in the city of Thessaloniki (Greece) and the conducted analysis and exploration of factors shaping the parental framework for school travel mode choice, this study takes a step further: the authors evaluate and propose a machine learning (ML) classification model, utilizing the pre-recorded parental perceptions, beliefs, and attitudes as inputs to predict the choice between motorized or non-motorized school travel. The impact of potential changes in the input values of the ML classification model is also assessed. Therefore, the enhancement of the sense of safety and security in the school route, the adoption of a more active lifestyle by parents, the widening of acceptance of public transportation, etc., are simulated and the impact on the parental choice ratio between non-motorized and motorized school commuting is quantified.

Organophosphate esters in the urban atmosphere of Thessaloniki city, Greece

The occurrence of organophosphate esters (OPEs) in the atmosphere of the urban area of Thessaloniki city, Greece was studied. OPEs were determined in particulate matter (PM2.5) and precipitation during the period 2020–2021. ∑OPEs in rainwater ranged from 520 to 4719 ng L−11 (mean: 1662 ng L−1) with tris (2-butoxyethyl) phosphate (TBOEP) and tris (1-chloro-2-propyl) phosphate (TClPP) being the most abundant compounds. TBOEP and TClPP as well as triphenylphosphine oxide (TPPO) and tris (chloroethyl) phosphate (TCEP) were the dominant OPEs in PM2.5. Concentrations of ∑OPEs in PM2.5ranged from 2.82 to 13.3 ng m−3 (mean: 5.93 ng m−3). Wet deposition fluxes of OPEs were estimated and air mass back trajectories were used to elucidate possible source profiles. An overall low health risk for local population via inhalation of OPEs was revealed.

Microplastic Particles in Sandy Beaches of Thessaloniki Gulf, Greece

Microplastic pollution is a major issue for aquatic ecosystems. In this study, an assessment of microplastic pollution in beach sediments of Thessaloniki Gulf is presented. Sand sampling was performed in October 2021, in three different coastal areas along the seashore of Thessaloniki Gulf, in NW Aegean Sea. In total, nine sand samples were collected and examined. The morphology of the detected microplastics was recorded: they were fragments and microfibers. Their abundance ranged from 0-32 items/m3. Higher concentrations of microplastics were observed in Karabournaki Beach, located in the city of Thessaloniki. It is the second largest city in Greece, inhabited by about 1,5 million people. Regarding the color, black, red, blue, green, and transparent microplastic fragments were found. Black and blue particles were the most common. Chemical detection and identification were performed with FT-IR spectroscopy. Four polymers were detected: polyethylene (PE), terephthalate (PET), high-density polyethylene (HDPE), polypropylene (PP), and polytetrafluoroethylene (PTFE). Polyethylene terephthalate was the dominant identified polymer (50%). The need for plastic pollution management in coastal areas, as well as the need to communicate the issue of plastic marine pollution and enhance public awareness, are discussed.

Putting theory into practice: A novel methodological framework for assessing cities' compliance with the 15-min city concept

Despite being the places where most people prefer to live and work, cities face significant challenges. Triggered by the COVID-19 pandemic, the 15-min city concept has emerged as the new urban planning paradigm that aims to cope with intense urban challenges by bringing the idea of living locally to the forefront. Although the concept of the 15-min city has a great potential to enhance the quality of life, its implementation could never be realised unless its theoretical principles are translated into measurable and evaluable dimensions. Thus, the current paper introduces a methodological framework that quantitatively assesses cities' compliance with the 15-min city concept through a sophisticated, holistic fuzzy index, the 15-MCiX. The proposed methodological framework was applied in the city of Thessaloniki, Greece, and highlighted that Thessaloniki largely embraces the concept of the 15-min city, achieving an average 15-MCiX score of 0.85 out of 1.0. Thus, a more ambitious yet meaningful target, such as the 10 or 5-min threshold, should be considered in dense urban environments like those in Europe. Finally, the pilot implementation underlined the great reliability, usability, and transparency of the proposed methodological framework, as well as its high transferability that could make it a valuable tool worldwide.

Identifying Barriers and Expectations in MaaS: Users’ and Stakeholders’ Perspective

Mobility as a Service (MaaS) is an innovative urban mobility concept that aims to provide a competitive alternative to the use of private cars, by integrating various transportation services. Until today, limited MaaS schemes have been implemented and, in most cases, without succeeding to justify the hype. For achieving the goals of MaaS it is essential to capture holistically the expectations and barriers, as perceived by both the end-users and the various involved stakeholders. This paper aims to bridge this gap, by conducting two surveys in the city of Thessaloniki, Greece; the first survey targeted local authorities, organizations and mobility providers, while the second survey focused on (potential) end-users. The responses of stakeholders were analyzed through the Analytic Hierarchy Process (AHP) method, in order to identify the importance of barriers and expectations. On the other hand, the responses of end-users were analyzed statistically and two ordered logit models were developed for identifying the characteristics of those that are more likely to adopt MaaS. The results of the analyses indicate that there is a loop between MaaS and private car usage; on the one hand, the dominance of private cars hinders the adoption of MaaS, but on the other hand, MaaS can be a “tool” for encountering car domination. The results also enhance the idea that public transport is an essential component of MaaS.

Does noise affect housing prices? A case study in the urban area of Thessaloniki

Real estate markets depend on various methods to predict housing prices, including models that have been trained on datasets of residential or commercial properties. Most studies endeavor to create more accurate machine learning models by utilizing data such as basic property characteristics as well as urban features like distances from amenities and road accessibility. Even though environmental factors like noise pollution can potentially affect prices, the research around this topic is limited. One of the reasons is the lack of data. In this paper, we reconstruct and make publicly available a general purpose noise pollution dataset based on published studies conducted by the Hellenic Ministry of Environment and Energy for the city of Thessaloniki, Greece. Then, we train ensemble machine learning models, like XGBoost, on property data for different areas of Thessaloniki to investigate the way noise influences prices through interpretability evaluation techniques. Our study provides a new noise pollution dataset that not only demonstrates the impact noise has on housing prices, but also indicates that the influence of noise on prices significantly varies among different areas of the same city.

Art Didactics and New Technologies in Primary School Field Practice: Augmented Reality Application for Multimodality

This paper is a result of a field application carried out in a public school in the city of Thessaloniki, Greece. We aimed at integrating an augmented reality application in the primary school curriculum. The role of Art Education in nowadays mostly has to do with specific tasks, traditional art methods and materials that will always have their place in the curriculum. Art education is a fundamental aspect of a well-rounded education. It goes beyond merely teaching artistic techniques; it instills valuable life skills, fosters creativity, and contributes to personal growth, cultural understanding, and societal enrichment. Digital technologies, especially in the post covid and postdigital era, have influenced both the education system in general and art didactics as well. The research question of the paper is how new technologies and applications are reinventing and reshaping art education. The use and the study of specific artworks is carried out in a way for the multisensory experience of contemporary cultural reality. The key is to find a true balance between the field art practice and the high-end tech integration. How can we address old school artworks and artistic content in a multimodal way? Can we address a class free lesson in school? By addressing this empirical, applied learning experience, we tried to facilitate student with the technology integration.

Satellite remote sensing to improve source water quality monitoring: A water utility's perspective

Polyphytos Reservoir provides the city of Thessaloniki with efficient and safe drinking water after appropriate treatment at the Thessaloniki Drinking Water Treatment Plant (TDWTP). This study evaluates the feasibility of utilizing open access satellite imagery and analysis tools to continuously, rapidly, at a low cost and precisely evaluate the water quality of large reservoirs like Polyphytos Reservoir. Thereby, more than 300 satellite images were analyzed, spanning a 9-year period from 2013 to 2022, using specific algorithms designed for determining surface water quality, such as Se2WaQ, NDWI and Oil Spill Index (OSI). These algorithms were used to estimate chlorophyll concentration (Chl-a), turbidity values (Tur) and hydrocarbon (OSI) presence. The generated results are compared with data records regarding the reservoir’s water level and chlorophyll and turbidity measurements in the reservoir and at the inlet of the TDWTP. This study shows that the examined satellite survey tools can effectively identify unanticipated formations on the surface of the reservoir and provide a quantitative assessment of the surface water quality using in-situ sampling for algorithms validation. The findings of the study were used to create a workflow that can serve as a guide for end-users interested in a low-cost, quick, continuous, and accurate surface water quality assessment of large reservoirs, using satellite remote sensing tools. It is anticipated that the information provided in this study would be useful to end-users community.

Modeling of shared mobility services - An approach in between aggregate four-step and disaggregate agent-based approaches for strategic transport planning

Shared mobility services are slowly penetrating European cities. Hence, transport models that are capable of modeling them are fundamental, to support policy-makers for making informed decisions. Many European cities, especially the small- and the medium-sized ones, continue to use the traditional four-step modeling approach. This approach does not have the necessary capacity to model the shared mobility services and there is a need to extend them. Hence, this research proposes an extended framework, which includes modules for synthetic population generation and fleet management. Furthermore, modules are also suggested for the estimation of emissions, car-ownership and induced demand, as such measures are increasingly expected by cities. Multiple equilibrium checks between the aforementioned modules are avoided in the design of this development, to reduce model complexity and convergence issues. The models and the algorithms used for the additional modules in this study can be replaced with alternative equivalent models, provided the inputs and outputs are consistent with the framework. As such, the framework is software agnostic. Based on a case study on the city of Thessaloniki, a proof of concept is provided. The intermediate modeling framework, proposed in this study, provides an opportunity for cities to evaluate and integrate shared mobility systems and form long term planning strategies. Besides, it acts as a bridge between the worlds of simple and complex modeling approaches and pave the way for reducing the reservations of the cities toward complex approaches, while preparing them for a smoother transition in future.

Assessment of Cu and Zn contamination and associated human health risks in urban soils from public green spaces in the city of Thessaloniki, Northern Greece

Assessment of Cu and Zn contamination and associated human health risks in urban soils from public green spaces in the city of Thessaloniki, Northern Greece

Evaluation of PM Chemical Composition in Thessaloniki, Greece Based on Air Quality Simulations

The average PM10 daily levels over the urban area of Thessaloniki, Greece, usually exceed the air quality limits and therefore the improved PM chemical composition and air quality modeling results that will facilitate the design of the most appropriate mitigation measures (e.g., limitations in wood combustion for heating purposes) are essential. The air quality modeling system WRF-CAMx was applied over a 2 × 2 km2 horizontal resolution grid covering the greater area of Thessaloniki for the year 2015, when Greece was still confronting the consequences of the financial crisis. The output hourly surface concentrations of twelve PM species at three sites of different environmental type characterization in the city of Thessaloniki were temporally and spatially analyzed. Carbonaceous aerosols (organic and elemental) are the major contributor to total PM10 levels during winter representing a 35–40% share. During summer, mineral aerosols (excluding dust) distribute by up to 48% to total PM10 levels, being the major contributor attributed to road traffic. PM species, during winter, increase in the morning and in the afternoon mainly due to road transport and residential heating, respectively, in addition with the unfavorable meteorological conditions. An underestimation of the primary organic carbon aerosol levels during winter is identified. The application of the modeling system using a different speciation profile for the fine particles emissions from residential heating based on observational data instead of the CAMS emissions profile revealed an improvement in the simulated OC/EC values for which a 50% increase was identified compared to the base run.

Pedestrian Crossings as a Means of Reducing Conflicts between Cyclists and Pedestrians in Shared Spaces

One significant and simultaneously interesting problem in urban mobility has to do with the study of shared spaces where various categories of users coexist and act together. This paper aims to examine the behavior and preferences of pedestrians and cyclists, who both coexist in a shared space infrastructure along the seafront (which has a length of around 4.0 km) of the city of Thessaloniki, Greece. Furthermore, the problems caused by the coexistence, such as at the locations where there are pedestrian crossings on the bicycle lane, are recorded and evaluated. Traffic calming measures aimed at improving the existing situation in terms of safety and comfort for both pedestrians and cyclists are also explored. Data were collected through a web-based questionnaire survey, which was distributed via email to students and employees of Aristotle University of Thessaloniki. A total of 1194 questionnaires were collected in the framework of the survey during the year 2021, including responses from both pedestrians and cyclists. The questionnaires were analyzed through the use of descriptive and inferential statistics; the latter method suggested several significant differences in how each group of users (pedestrians or cyclists) perceived their behavior compared with the other. Latent variable and path models were estimated to investigate the behavior and attitude of users towards the crossings, examined as a function of their perception towards the other group; perception about the benefits of the infrastructure; preference for additional interventions; and overall opinion about the quality of the shared space area. The results suggest that forms of aggressive behavior, preference towards using the crossings, and the perceived safety are affected by the aforementioned factors. The results of this study can inform decision takers and decision makers in the area of land use regarding policy recommendations for facilitating interactions between pedestrians and cyclists in shared spaces.

Climate change impacts on heating and cooling energy demand in residential building units. Application in the city of Thessaloniki, Greece

The present study aims to evaluate the effect of climate change on the heating and cooling energy needs of a residential building unit, located in the city of Thessaloniki, Greece. Future weather files have been generated using both statistical and dynamical downscaling methods. In the first case, the Meteonorm weather generator was used to generate a future weather file, while for the dynamic downscaling approach, the Hadley Regional Model 3 (HRM3), coupled with Hadley Climate Model 3 was employed. The generated future weather datasets have been then used as an input parameter in the dynamic energy performance simulations of the residential building unit with Energy Plus. For all examined weather datasets, the simulation results show a decrease of the heating energy use, an effect that is strongly counterbalanced by the rise of the cooling energy demand.