Societal benefits supplied by urban green spaces (UGS) to city dwellers are vital to maintain and increase urban citizens’ quality of life (QoL) [1
]. UGS are essential in mitigating high summer temperatures of their grounds and nearby surroundings [3
], and are vital in air pollution removal and noise abatement [5
]. They are also highly regarded for positive effects in promoting their visitors’ physical and mental health [7
] and providing opportunities for social interactions and recreation [9
]. The QoL benefits derived from UGS are increasingly central to urban society [12
] and, therefore, understanding visitors’ attitudes and perceptions of UGS is essential for informed urban planning [14
]. However, exploring visitors’ perceptions of green spaces is challenging as it depends on cognitive, affective, and behavioural components and, therefore, sensory perceptions are individually different [16
Consequently, sensory dimensions and experiential contacts with the environment are crucial building blocks of area-based perceptions [20
], and subjective well-being is driven by location-specific environmental endowments [22
]. For example, increasing neighbourhood green space ratio proved to have a positive effect on residents’ self-reported life satisfaction in Australian capital cities [23
]. Hence, the relation between UGS visitors’ perception and green space characteristics is a key factor to understanding the mechanism of how tangible and intangible benefits are derived from ecosystems supplied by UGS [24
]. Existing research varies from a focus on a particular UGS function to a set of services. For example, Nasution and Zahrah [25
] linked community perceptions of public open spaces to QoL in Medan, Indonesia, and Oliveira, et al. [26
] linked visitors’ preferences of UGS to their perceived cooling effect of UGS in Lisbon, Portugal. The association of perceived well-being benefits to a range of ecosystem services provided by UGS and urban green infrastructure has been investigated by several scholars [27
]. In addition, a mediation effect of perceived restorativeness was found between settings of experiential green space contact (perception of nature, length of visit, and level of biodiversity) and self-reported well-being [30
]. These studies provide the context for the first pillar of our research: visitors’ level of satisfaction and perceived QoL contribution of UGS are key individual-level measures that are subjectively affected by area-based green space characteristics.
The second pillar of our study centres on the possible suitability of frequency of crowd-sourced geo-tagged data, recorded within UGS, to gauge visitors’ perception of UGS. Scholars who have researched the sensory dimensions of UGS have tended to use conventional data sources to identify associations and causalities in the human attitude towards UGS [32
]. Therefore, sources of information are based on traditional data acquisition methods such as questionnaire surveys [15
]. For example, Baur et al. [16
] used randomly-distributed mail questionnaires to capture green space users’ and non-users’ attitudes toward urban nature parks in Portland, OR, USA. Questionnaire surveys were also used by Lo and Jim [34
] to assess preferences of Hong Kong citizens for UGS.
Despite the successful application of questionnaire-based analytical methods, it is timely to test the capabilities of data crowd-sourcing to understand visitors’ attitudes towards UGS. The authors’ decision to use crowd-sourced data was three-fold. Firstly, UGS visitors of recent years can use location-aware technologies to spatially log their activities; for example, UGS visitors can geo-tag their photographs that they take during their UGS visits, or log trajectories of their physical activities. Second, geo-tagged user-generated content (UGC), a form of Big Data, is able to expose patterns and relationships which would be hidden from questionnaire-based methods [32
]. Third, geo-located and voluntarily gifted UGC has already demonstrated potential in other fields of geographic science [36
]. For example, Feick and Robertson [39
] used geo-tagged photographs to explore spatial expressions of urban places, and geo-tagged photographs helped Richards and Friess [40
] to understand cultural ecosystem services supplied by mangroves in Singapore. Santos, et al. [41
] used GPS track-logs recorded by mountain bikers and runners in a UGS of Lisbon, Portugal, to present spatial overlap and potential conflicts of interest in recreational trail use. Due to their intangible nature, cultural ecosystem services, such as aesthetic appreciation, and recreational capacity are challenging to quantify [17
]. Therefore, scholars increasingly utilise geo-tagged UGC to evaluate aesthetic enjoyment [40
] and recreation [41
] as their volume and spatial patterns can indicate recreational capacity and aesthetic appreciation [40
]. Furthermore, the InVEST ecosystem modelling tool implements geo-tagged UGC to evaluate cultural ecosystem services [48
]. Dunkel [49
] also suggests that geo-tagged UGC “may contribute to a more balanced assessment of the perceived landscape”. Therefore, our assumption is that the frequency of geo-tagged user entries should enable us to gauge visitors’ perceptions of UGS.
The present study aimed to support urban planners and green space managers from the city of Szeged, Hungary, with information on the role of the city UGS in citizens’ QoL. Therefore, expert interviews were conducted with urban planners and environment managers of the Szeged City Council to assess their needs. Their interest was to understand how green space characteristics influence the use and perception of the city green spaces. The study was designed and conducted accordingly and aimed to answer the following two research questions:
Research Question 1: To what extent did perceived green space characteristics influence visitors’ levels of satisfaction with the visited green spaces and the self-reported QoL contributions of the study areas?
Research Question 2: Was the frequency of geo-tagged photographs and running trajectories statistically related to visitors’ perception of UGS?
The aims of the study were:
To reveal the role of green space characteristics in visitors’ self-reported levels of satisfaction and the perceived QoL contribution of the studied green spaces.
To statistically explore the potential of frequency of geo-tagged photographs and running trajectories in revealing human perceptions of UGS.
The present study fulfilled two goals. Firstly, it uncovered the role of perceived green space characteristics in visitors’ level of satisfaction and the perceived quality of life (QoL) contribution. Secondly, the research demonstrated the potential of frequency of geo-tagged photographs and running trajectories in revealing human perceptions of urban green spaces (UGS).
4.1. Answer to Research Question 1
The results demonstrated the extent to which the seven perceived green space characteristics influenced visitors’ levels of satisfaction and the self-reported QoL. Every model revealed that visual appearance of the UGS was the most crucial predictor of visitors’ levels of satisfaction and the self-reported QoL (at 1% level of significance in Models 1, 2 and 4; at 5% level of significance in Model 3). The perception of nature was the second most influential green space characteristic that highly affected visitors’ satisfaction in Models 1 and 2 already at 1% level of significance. The third most crucial green space characteristic was the perceived recreational capacity. This positively influenced visitors’ level of satisfaction with the UGS in Models 1 and 2 at 5% level of significance, and the perceived QoL contribution of the five UGS in Model 4 at 5% level of significance. Of lesser importance, habitat contributed to visitors’ levels of satisfaction in Models 1 and 2 at 10% level of significance. Another notable perceived green space characteristic, the microclimate regulation, affected visitors’ self-reported QoL in Model 3 at 10% level of significance.
Our work identified that regulating ecosystem services were largely underrated by survey participants. Noise abatement, microclimate regulation and air purification services supplied by the study areas seemed to have only minor significance on visitors’ perceptions. Likewise, habitat was underappreciated. There are two possible arguments to explain these results. The first is the mainly ornamental purpose of Szeged’s city centre green spaces means they are likely to contribute less to regulating ecosystem services than those which are located away from the city centre. The second possible reason stems from a lack of societal awareness of the fundamental importance of regulating ecosystem services, in that the benefits derived from regulating services are not directly “tangible” or perceivable. Even though cultural ecosystem services such as the scenery and the recreation are also intangible, green space visitors can directly benefit from them through aesthetic appreciation, relaxation and physical activity. Therefore, visitors feel more attached to cultural services than regulating or habitat services. These findings are confirmed by results of earlier studies. Tyrväinen, et al. [28
] found recreational opportunities supplied by UGS and their contribution to pleasant cityscape more influential to survey participants than noise abatement, dust removal, or ameliorating climatic conditions. Survey participants in Bilbao, Spain, rated regulating ecosystem services of lower importance than cultural services from which they directly derive well-being benefits [66
]. They also found a lack of societal awareness of ecosystems’ capacity to benefit society. The very positive contribution of perception of nature to visitors’ level of satisfaction is a welcome addition to the findings of our study. This may be explained by perceived restorativeness mediating the effect of the experienced nature qualities on visitors’ level of satisfaction [31
4.2. Answer to Research Qusetion 2
Our findings suggest that visitors' perception of the UGS were effectively conveyed through the seven questionnaire items, while frequencies of geo-tagged photographs and running trajectories were only partly related to individual-level perceptions of the study areas. The number of running trajectories and the proportion of images picturing green space aesthetics were found significant at 1% and 5% level of significance, respectively, in relation to the perceived QoL contribution of the UGS in Model 4. However, the two crowd-sourced area-based variables were not strong enough to support survey participants’ satisfaction with the study areas. Consequently, the potentials of frequency of geo-tagged photographs and running trajectories were limited in revealing human perceptions towards the studied UGS. On the other hand, geo-tagged photographs and running trajectories exposed spatial patterns in their distribution. As it can be seen in Figure 3
, the spatial concentration of geo-tagging locations of photographs in ER, DU, and SZ are immediately identifiable. The same is true for the concentration of running trajectories in ER (Figure 2
The findings of our work are in line with those from previous studies by showing that Big Data, in the present case geo-tagged UGC, is suitable to identify general relations [35
], while traditional data sources, such as variables from a questionnaire survey, are able to reveal causalities [32
]. The findings also support other studies on trajectory and photography-based crowd-sourced geo-tagged data that indicate recreational capacity and aesthetic appreciation of public open spaces [40
4.3. Planning and Management Implications
4.3.1. Planning Regulating Ecosystem Services in Line with Residents’ Aesthetic and Recreational Needs
Aesthetics are a contextual feature affecting personal perspectives and have implications for landscape and ecological planning and intervention [68
]. Therefore, from a planning perspective an UGS providing regulating ecosystem services such as microclimate regulation or air purification might be more appreciated by visitors if it also offers high aesthetic enjoyment. Physical well-being is often achieved through recreational activities in green spaces [21
], and according to our results recreational opportunities offered by UGS are crucial to their visitors.
Hence, it is vital that urban planning and management implement development of regulating ecosystem services with a consideration of cultural services in their strategic and operational goals. In addition, education is needed to raise environmental awareness of intangible ecosystem services as this would enable a better appreciation of them as crucial sources of our well-being benefits [66
4.3.2. Combined Use of UGS Visitors’ Perceptions and Their Crowd-Sourced Geo-Tagged Data
There are interventions in green space planning and management that require qualitative knowledge, for example, to understand visitors’ perception of the scenery of the UGS. To achieve this goal, questionnaire-based methods are still required. However, green space managers need to be aware of the measured green space usage and appreciation, and this is the specific area where geo-tagged UGC can contribute valuable information to help management decisions. Frequency and spatial concentration of running trajectories may function as measured recreational green space usage [41
], whilst the spatial concentration of geo-tagging locations of visitors’ photographs can predict environmental aesthetics that attract green space visitors [69
Even though geo-tagged UGC has potential planning implications [49
], currently there is no evidence that urban green space managers extensively use questionnaire data in conjunction with UGS visitors’ geo-tagged data. The authors recommend that scientific communities further investigate a mixed-methods approach; a collective application of questionnaire-based variables and crowd-sourced geo-tagged data on the use and aesthetic appreciation of UGS. When technically matured, such an approach could lead to better evidence-based decisions in urban planning and management.
4.4. Future Outlook
Prior to the work the authors assessed the needs of urban planners and environment managers to understand residents’ perception of well-being benefits they derive from UGS. Future studies will follow in which urban planners and green space managers will be involved in all phases of the work, from the study design to the data acquisition and analysis to the result implementation. This would guarantee the full compatibility of the methodology and the results in decision support practices.
Individual-level objective variables, such as respondents’ socio-economic status, affect individual perceptions often leading to very different self-reported satisfaction [71
]. Therefore, individual circumstances can be also incorporated in subsequent analyses. This would allow the authors and city councils to understand how perceived green space characteristics affect the satisfaction and well-being of various societal groups. In addition to the ordinal logistic regressions applied here, future studies could perform multi-level models in order to identify contextual effects of area-level characteristics of the green spaces on individual-level QoL and health.
The authors conducted the study as a pilot in Szeged. As the methodology is easily transferable to other cities, the authors would like to pilot it in other urban areas to gain more experience and possibly detect differences in preferences in perceived well-being benefits derived from urban green spaces.
The present study can be considered as a basis to understand the city as a complex system. The methods applied here for UGS can be transferred to the city scale. Future research may apply methodologies that go beyond green spaces and use questionnaires and crowd-sourced geo-tagged data for a better comprehension of other urban resources and services.
This study used answers from a questionnaire survey together with the frequency and spatial distribution of crowd-sourced geo-tagged images and running trajectories of five UGS in the city of Szeged, Hungary. The aim was to predict the influence of perceived green space characteristics, reported by surveyed green space visitors, on two well-being variables: visitors’ levels of satisfaction with the green spaces and the perceived quality of life contribution of the respective area. The ultimate goal was to inform urban planners and green space managers of Szeged about the effects of green space characteristics on well-being benefits that the citizens obtain from UGS. Four models of ordinal logistic regression analysis were applied. They disclosed that perceived green space characteristics with direct well-being benefits strongly influenced visitors’ green space attitude. The two well-being variables were particularly dependent on the perceived scenery of the study areas. Recreational capacity, which has direct well-being benefits, was also able to predict the two dependent variables. Perception of nature, an indirect well-being benefactor, was a strong predictor of visitors’ levels of satisfaction with the green spaces. Perception of green space characteristics referring to vital regulating ecosystem services with provision of indirect well-being benefits had a low influence on green space visitors’ levels of satisfaction and self-reported quality of life contribution of the study areas. The two crowd-sourced area-based variables, the geo-tagged photographs and running trajectories, were able to explain the perceived quality of life contribution of the green spaces but failed to explain visitors’ green space satisfaction. In turn, the geo-tagged UGC revealed fine-scaled spatial patterns within the study areas which highlighted the site popularity and real green space usage.
The following conclusions can be drawn for urban planning and management: Consideration of site aesthetics and recreational services is crucial for UGS development, and regulating ecosystem services should be planned accordingly. Awareness of the importance of regulating ecosystem services should be raised by environmental education. The joint use of questionnaire surveys, delivering perceptual information on UGS, and geo-tagged UGC, revealing real recreational green space usage and aesthetic appreciation, is recommended for further investigation. When technically ready, the approach could promote informed decisions in urban planning and management. This study has been carried out in close collaboration with the administration of the city of Szeged and the results will be presented to the relevant administrative units in order to assure citizens’ needs-centred planning.