Public Perception of Tourism Cities before and during the COVID-19 Pandemic through the Lens of User-Generated Content

: The COVID-19 pandemic (coronavirus disease of 2019) sent the world into disarray and devastated the global tourism economy. In 2020 alone, the number of international tourists dropped by roughly 1.1 billion. This study examines user-generated content (UGC) on social media to elucidate the shift in people’s perceptions of popular tourism cities from before the pandemic to during the pandemic. This paper analyzes the characteristics of the cues in tourism-city-related UGC (particularly those related to the pandemic) and identiﬁes the cues that resonate most with the public. This paper collected the data using Instagram’s application programing interface and then sorted the UGC based on content, type, time, likes, share, and comments. Between 1 January 2019 and 31 December 2019, it collected a total of 207,752 pre-pandemic posts and 173,131 peri-pandemic posts. The ﬁndings reveal that, during the pandemic, the interactivity of city-related UGC dropped, and only pandemic-related keywords gained public attention. By comparison, pre-pandemic positive posts mentioned local features and contained calls to action that were generally well-received. The ﬁndings also validate that UGC effectively reﬂects and enhances overall public perceptions, suggesting that, in a future which is forced to co-exist with SARS-CoV-2 in the long term, it is important to understand the positive and negative inﬂuences of UGC on tourism cities.


Introduction
City image (CI) represents the interaction and connection between people and city resources. It also reflects the experiences and memories of the city [1]. By analyzing the integration of societies and spaces and understanding cities' different meanings and purposes, it can better manage our cities. For people feeling estranged from a specific city, their impression of the city can be improved by the visual information they receive. Through visual content analysis and thematic analysis, this paper extracts people's imaginations and expectations from their primary perceptions and their historical, cultural, artistic, and life experiences [2]. A sustainable city image on social media can be seen as a type of soft power for building people's trust in the city [3]. As users on a social media platform increase, the platform's impact on CI increases concurrently, forming public trust that trumps the effects of official promotional content [4].
Key information and content should be specifically designed to improve content efficiency and enhance user interaction [5]. Another approach is to study the behaviors of social media users and to apply the results to make better decisions [6]. Although social media marketing is more affordable than other forms of marketing, the conversion rates of social media marketing are comparatively lower than other platforms. Therefore, utilizing user-generated content (UGC) on social media is a major challenge for city marketers. City planners can determine the effectiveness of social media interaction by examining the decisions made by users. Examining public engagement helps planners to determine accurately people's behaviors and demands and improve the community of cities [7]. The COVID-19 pandemic sent the world into disarray and devastated the global tourism economy. Based on statistics released by the World Tourism Organization of the United Nations (UNWTO), there were roughly 1.1 billion fewer international travelers in 2020 than in the previous year, a reduction of between 70% and 75%. The loss in international travel revenue was estimated to be USD 1.1 trillion, and the impact on the global economy was estimated to be USD 2 trillion. The World Tourism Cities Federation (WTCF) surveyed global travel trends in 2020. The findings indicated that international travel and revenue declined by over 60%; the international tourism industry lost 197.5 million jobs; GDP declined by USD 5.543 trillion; international travelers declined by 73%; and domestic travelers declined by 64% in 2020 compared to the previous year. Hong Kong's tourism industry was hit especially hard, starting from the mass protest event in 2019. That year, 55.91 million fewer travelers visited Hong Kong, a 14.2% decline compared to the previous year. Statistics released by the Office of National Statistics (ONS) of the United Kingdom, indicated that the number of travelers in 2020 was cut by three-quarters compared to the previous year. Thailand, whose economy relies heavily on the tourism industry, continues to be ravaged by COVID-19. Compared to pre-pandemic conditions, Thailand's tourism economy shrunk by 99%.
Therefore, the main purpose of this study is to analyze the UGC posted on social media to determine users' tourism city perceptions, with an emphasis on users' demand for and feelings towards city-related UGC during the pandemic. The secondary objective of this study is to extract city information [8] from UGC with the goal of obtaining a large amount of unstructured data. Pre-pandemic and post-pandemic city-related cues were extracted from the data and used to analyze post interactivity. This paper examines the shift in users' perceptions of sustainable tourism cities from before the pandemic to during the pandemic in the following two stages: 1.
This paper first examines the evolution in the CI of major tourism cities from before the pandemic to during the pandemic; 2.
It then surveys the cues in UGC about three tourism cities posted on social media to identify the cues that most resonated with the public before and during the pandemic.
In Section 2, this paper reviews relevant literature and introduces theories related to city-related features, urban communities, and city-related UGC. In Section 3, it outlines our hypotheses on the effects of the frequent use of constructive cues in city-related UGC before and during the pandemic on the interactivity of social media posts. These hypotheses allow us to evaluate the influence of information cues on post interactivity. In Section 4, it outlines our research process and methodologies. Section 5 details our analysis results. In Section 6, this paper provides a conclusion and suggestions on the management of city-related UGC.

City-Related Features and Urban Communities
Recent evidence shows that, with the rise of the Internet, users have become a vital part of image formation. They not only spread city image to their family and friends via word of mouth, but also use a variety of media platforms to interact with others, which is extremely helpful to spread positive city information. The advent of Web 2.0 and the rise of social media have further redefined the information distributors of digital media. Different from traditional offline media, a variety of travel information circulates over the Internet and on social media platforms. These platforms allow users to share their personal experiences and spread their perceived sustainable city image, as well as encourage users to interact with one another in many ways, such as through travel blogs, message boards, or in-app messengers. However, the rise of the Internet has weakened the influence of traditional media, while strengthening the influence of online social media.
CI reflects or captures the features of a city. These features can be regarded as the characteristics of the city. When people notice meaningful city features, they become invested in the city. This investment consequently translates to revisitation willingness. By analyzing city features, it can determine how these features impact visitation willingness and compare the tourism popularity of different cities. Cities can also promote their features to attract potential visitors and predict tourist preferences and recommendation willingness. Given that people's preferences greatly influence their recommendation willingness, key features become an important indicator of public behavior.
People use social media for entertainment and to enrich themselves. Some rely on the convenience of social media platforms to gain emotional support and recognition [9], while others are motivated by the desire to share content, connect with others, express themselves, or achieve personal goals [10]. Past studies on city promotion found that strong emotional cues [11], such as surprise or pleasure, were better at gaining public recognition. Other studies found that presenting the right information facilitated the development of common beliefs within social communities, mentioning that the mediating effects of information on behaviors and interactions increase concurrently with the functionality and emotional stimulus [12].

CI and UGC
With the prevalence of social media today, city planners are gradually shifting their promotional strategies. Planners now try to create a sustainable city image in line with people's experiences to express authenticity and personality. This shift has exposed the strategic value of UGC in forming CI and the benefits of using UGC to adjust or redesign CI. Statistics on social media show a spike in the growth of travel-related posts in recent years, turning researchers to social media for the collection of first-hand data. Social media posts have become evidence of people's travel decisions and their perceptions of the cities they visited. They have also been used to compare seasonal trends through time and space or to adjust existing plans to prevent over-promoting regional images. Social media posts have also been used in the meta-analyses of markets to design more accurate strategies to attract domestic and international travelers.
A previous study that analyzed the consistency between CI and city features found that the urban value conveyed by Mexico City was correlated to the information posted by the public. Marine-Roig (2017) compared official city images of Peru and those posted by the public and found significant differences between the two sets of images. People were more interested in the details of everyday life, while official images focused on promoting Peru's heritage. UGC reflects people's preferences and perceptions. Subsequently, people tend to prefer posting content on a universal platform, where they are able to convey their thoughts without having to learn new features.
The importance of social media manifests itself in its influence on people's emotions and experiences and in the ability to co-create city experiences [13,14]. In terms of CI design, Hjalager (2010) found an increased willingness among cities to strengthen their management of city-related UGC and formulate plans that support the promotion of city features and CI, including service development [15], experiential design [16], and event creation plans [17]. The development of UGC facilitates the formation of CI [18,19].
UGC has many advantages, including data diversity and public engagement [8]. Existing studies on UGC largely focus on content functionality or emotional exchange. The user-generated content (UGC) of urban knowledge represents a type of people-centered information exchange and a comprehensive presentation of people's extensive experiences in a collaborative environment. Originating from a people-oriented interactive environment of social media, UGC promotes multi-dimensional information interaction while adding value to the characteristics of cities through the activation of information technology. There are no known studies that focus on recent events and how positive cues serve as incentives for user involvement. Key features are an important indicator of public behavior. Existing studies on CI cannot fully explain the relationships between the key features of cities and public behaviors. More experiences and evidence are required to validate the effectiveness of city information to promp public perception and involvement. Therefore, this paper examines the UGC posted on social media to identify key information cues relating to sustainable tourism cities.
In terms of UGC research, researchers have used keyword analysis to explore the multidimensionality of political texts and public policies, or to understand extreme differences before and after the German political policy intervention. Other new applications of UGC analytics include crisis identification in cities or decision-making evidence of relevant governments. Additional applications are in-depth analyses of the intervening factors in citizens' welfare distribution, and the use of UGC to control research topics in public administration for policies that meet public needs. Additionally, to promote the rise and recovery of the urban economy and tourism, the disclosure of key elements of UGC, including symbolic elements that contain user-generated content, the online travel image of the destination, and the online image of the smart tourist destination, further benefits the refinement and alignment of urban elements.
The rapid development of social media and the Internet has promoted the rapid growth of UGC. This growth also affects a series of processes that take place before, during, and after a trip. In the tourism industry, the UGC of cities serves two main purposes: first, to offer information, and second, to provide a platform for people to make recommendations about cities, share ideas, and express travel intentions. In recent years, the online image of destinations has been mainly based on Twitter, Facebook, other social media travel booking platforms, online travel agencies (OTA), or information about attractions, hotels, or restaurants that represent the destination. Reviews and information published via online platforms are the foundation of UGC. When people actively, enthusiastically, and voluntarily express opinions, their comments represent the influence of the wisdom of the crowd. UGC is defined as community messages generated by non-experts. It can be regarded as a key indicator of successful interactive content, which is the main reason UGC is receiving more attention in communities.

Research Hypotheses
The driving force behind CI is the reason for its influence on public behavior [20,21]. People's travel behavior is driven by internal motivation, such as desire and demand, combined the formation of city perceptions through external stimuli [22], or by internal factors, such as human desire, reputation, and social interaction, combined with tangible resources, such as beaches, entertainment facilities, or cultural attractions [23]. Therefore, it is necessary to understand city perceptions in order to effectively promote cities. Increasing people's knowledge about humanizing cities can help to enhance the perception of cities and improve travel intentions. Therefore, the exclusive value of the main impression of a city in network communities can be regarded as an indispensable element of a city. Market segregation, product development, and promotional plans are useful tools for promoting cities [24]. CI can be used to categorize public traits and open targeted dialogues with different groups of people. Previous empirical studies found that CI is a key factor influencing public involvement [25,26]. The types of city perceptions and rationale for selecting specific CIs can be determined by examining public behaviors [27][28][29].

City Perception and UGC Cues
Each CI is unique and contains distinct regional characteristics and imagery. They are often linked to people's attitudes [30], values [31], and beliefs [28,32]. CI influences pubic behavior [27], loyalty [33], satisfaction, and recommendation willingness [26,34], leading to different travel motivations [28]. Although UGC continues to provide essential clues about cities frequently, the disruption caused by the COVID-19 pandemic is bound to have an impact on the interactions of community posts. Therefore, this paper hypothesizes that the frequent use of city-related cues in UGC before the pandemic affected the interactivity of social media posts. The hypotheses formulated in this study are as follows: Hypothesis 1. Before the pandemic, user-generated posts that frequently and actively provided city-related cues affected the public's post interactivity. Hypothesis 1a. Before the pandemic, user-generated posts that frequently and actively provided city-related cues affected post likes.
Hypothesis 1b. Before the pandemic, user-generated posts that frequently and actively provided city-related cues affected post comments.

Negative Intervention and UGC Cues
In sociology, negative intervention is often used to describe disruptions in the decisionmaking process. Based on negative interventions, causality tools can be used to determine the adjustment conditions and carry out reform [35]. Subsequently, crisis management [36] and risk management [37][38][39] influence the relationship between CI and negative interventions [40]. For example, pandemic fear, terrorism, and protests negatively impact CI. Perceived risk and anxiety from lack of information and disease outbreak also impact CI. Negative interventions critically impact prevention conditions during a crisis. For example, negative interventions related to flu risk greatly influence prevention awareness among overseas travelers [20]. Moreover, the lack of information concerning disease or flu increases the public's perceived risk and anxiety and greatly influences travel behaviors [41,42]. According to the above studies, surveying the performance characteristics of personal messages helps to understand whether people's travel habits contain prevention measures and to reduce the effects of negative interventions on cities.
The COVID-19 pandemic greatly reduced the number of travelers in 2020, devastating the tourism industry. Therefore, this paper hypothesizes that the frequent use of city-related cues in UGC during the pandemic affected the interactivity of social media posts. The hypotheses formulated in this study are as follows: Hypothesis 2. During the pandemic, user-generated posts that frequently and actively provided city-related cues affected the public's post interactivity.

Hypothesis 2a.
During the pandemic, user-generated posts that frequently and actively provided city-related cues affected post likes.
Hypothesis 2b. During the pandemic, user-generated posts that frequently and actively provided city-related cues affected post comments.

Selecting UGC on Instagram
To elucidate the interactivity of city-related UGC before and during the pandemic, this paper employed a content mining approach to collect UGC on social media for analysis and evaluation. It subsequently formulated effective inferences based on the data [43]. Past studies on CI largely analyzed data from Facebook and Twitter [18,44]. This study selected Instagram, which has a higher volume of visual content. Therefore, the platform is uniquely positioned to market cities and is the preferred social media platform for CIrelated organizations to connect with the world [45]. The research framework comprised three steps. In Step 1, this paper collected UGC data from Instagram. In Step 2, it coded the unstructured text data and established code categories. In Step 3, this paper extracted and coded the key clues and assessed the reliability of these clues based on context, theme, and expert opinions.
This study extracted useful information from UGC to determine city-related clues and characteristics before and during the pandemic [46]. Instagram was chosen as the source of the research data. Since its launch in October 2010, Instagram has provided its users with instantaneous information. Users also share snippets of their lives on the platform, leading Instagram to become one of the most popular social media platforms in the world. Given that Instagram is generally recognized as an image-sharing platform, it has become a target platform for text-focused social media research. Instagram users typically attach images, videos, or hashtags to their posts. These attachments help to create and expand communities and prompt discussions.

Data Collection
This study first investigated city rankings in surveys conducted by different institutions in 2019. Due to the expansion of the study scope to include the comparison of cities in Eurasia, cities in France, Spain, and the United States, as compiled and ranked by the United Nations World Tourism Organization, were not selected. Instead, Hong Kong, Bangkok, and London were included in the study as they were the top city destinations published by Euromonitor International, an organization with more regional coverage. It is hoped that this study provides a direct comparison regarding various information, needs, or ideas about Eurasia cities with diverse cultures or urban characteristics. According to the Top 100 City Destinations: 2019 Edition published by British market survey company Euromonitor International, the three most popular tourism cities were Hong Kong, Bangkok, and London. Therefore, this paper performed a textual analysis of Instagram posts involving these cities to examine the message design and social interactivity of related posts [46]. This paper collected the data using Instagram's application programing interface and then sorted the UGC based on content, type, time, likes, share, and comments.

Keywords and Interactivity Analysis
Instagram posts are extremely casual, often containing punctuation errors, spelling errors, abbreviations, and emojis. This paper preprocessed the content by deleting links, people's names, and strange symbols to minimize the impact of these factors on the analysis results. It selected keywords concerning CI information or describing the features and types of CI. The purpose of this semantic analysis was to identify word characteristics, determine how often specific words were used by employing a standard natural language parser, and determine the semantic similarities between words and word categories [47]. The analysis results were then verified by an expert in the field without conflicts of interest. The preprocessed data enabled us to compare the thematic categories and words of the posts based on their similarities and evaluate whether the cities conveyed certain values and strategies [48]. This paper discarded irrelevant keywords before discussing and selecting the CIs and clues based on the semantic analysis results. Finally, it conducted a regression analysis on the one hundred most frequently used keywords to determine their influences of post interactivity.

Reliability and Validity
For reliability and validity analysis of the data, principal component factor analysis was performed to test the factor validity of the scale. The factor characteristic value of the pre-pandemic UGC cues had a total variance of 60.537% and a KMO value of 0.642. The factor characteristic value of the pre-pandemic UGC cues had a total variance of 69.561% and a KMO value of 0.63. The expected load factor for all items is >0.5, indicating good convergence and discriminant validity. In addition, the reliability test produced a Cronbach's alpha of 0.773 for the pre-pandemic UGC cues and 0.725 for the pre-pandemic UGC cues. Each of these results shows good reliability.

Hypothesis Testing and Data Verification
The results for Hypothesis 1 (before the pandemic, user-generated posts that frequently and actively provided city-related cues affected the public's post interactivity) achieved Sustainability 2021, 13, 14046 7 of 20 statistical significance (β = −0.031, p < 0.000). Therefore, H1 was supported. The results for Hypothesis 2 (during the pandemic, user-generated posts that frequently and actively provided city-related cues affected the public's post interactivity) achieved statistical significance (β = −0.031, p < 0.000) (Tables 1 and 2). Table 1. Summary of hypotheses.

ID Hypothesis Hypothesis Verification
Hypothesis 1 Before the pandemic, user-generated posts that frequently and actively provided city-related cues affected the public's post interactivity. Established

Hypothesis 1a
Before the pandemic, user-generated posts that frequently and actively provided city-related cues affected post likes. Established Hypothesis 1b Before the pandemic, user-generated posts that frequently and actively provided city-related cues affected post comments. Not established Hypothesis 2 During the pandemic, user-generated posts that frequently and actively provided city-related cues affected the public's post interactivity. Established

Hypothesis 2a
During the pandemic, user-generated posts that frequently and actively provided city-related cues affected post likes. Established

Hypothesis 2b
During the pandemic, user-generated posts that frequently and actively provided city-related cues affected post comments. Established The results for Hypothesis 1a (before the pandemic, user-generated posts that frequently and actively provided city-related cues affected post likes) achieved statistical significance (β = −0.031, p < 0.000). Therefore, Hypothesis 1a was supported. However, the results for Hypothesis 1b (before the pandemic, user-generated posts that frequently and actively provided city-related cues affected post comments) failed to achieve statistical significance (β = 0.003, p < 0.229). Therefore, Hypothesis 1b was rejected. The results for Hypothesis 2a (during the pandemic, user-generated posts that frequently and actively provided city-related cues affected post likes; β = −0.032, p < 0.000) and Hypothesis 2b (during the pandemic, user-generated posts that frequently and actively provided cityrelated cues affected post comments; β = −0.008, p < 0.001) achieved statistical significance. Therefore, both hypotheses were supported.

Cue Characteristics of City-Related UGC
The results show that the organization of content on social media pages exerts a significant influence on the responses of users to the content and their behavioral participation. The results of the various verification tests are presented below.

Hong Kong
This paper analyzed the posts concerning Hong Kong and found that the UGC contained three distinct keyword groups, namely (1) politics-related keywords, (2) pandemicrelated keywords, and (3) calls to action, which had higher interactivity. For the pre-pandemic posts, those with more likes contained travel-related keywords, such as "tour" and "show", and politics-related keywords, such as "protest" and "people", Posts containing politics-related keywords, such as "police" and "protest", gained more comments. Posts containing calls to action, such as "post", "link", and "like", gained more user interaction. By contrast, posts solely containing travel information or general passive information, such as "food", "fashion", "shop", and "award", were informative, but were less able to prompt user interaction.

Hong Kong
This paper analyzed the posts concerning Hong Kong and found that the UGC contained three distinct keyword groups, namely (1) politics-related keywords, (2) pandemicrelated keywords, and (3) calls to action, which had higher interactivity. For the prepandemic posts, those with more likes contained travel-related keywords, such as "tour" and "show", and politics-related keywords, such as "protest" and "people", Posts containing politics-related keywords, such as "police" and "protest", gained more comments. Posts containing calls to action, such as "post", "link", and "like", gained more user interaction. By contrast, posts solely containing travel information or general passive information, such as "food", "fashion", "shop", and "award", were informative, but were less able to prompt user interaction.
For the peri-pandemic posts, those that gained more likes contained pandemic-related keywords, such as "coronavirus" and "avail", or calls to action, such as "share" and "link". Similarly, those that gained more comments contained pandemic-related keywords, such as "coronavirus" and "COVID-19". Due to Hong Kong's political situation, posts containing politics-related keywords, such as "people" and "country", also gained higher user interaction, and those containing calls to action, such as "link", "share", "post", and "friend", gained more comments. By contrast, posts pandemic containing general information published during the pandemic and that contained keywords, such as "artist", "design", "hkig", "gallery", "fashion", "restaurant", and "culture", were unable to attract users' attention.

London
This paper analyzed the posts concerning London and found that the UGC contained three distinct keyword groups, namely (1) calls to action, (2) keywords prompting positive emotions or national image, and (3) purely informative travel-related keywords. For the pre-pandemic posts, posts with more likes and comments contained keywords that expressed the features of the city, such as "story", "thisislondon", and "film", or calls to action, such as "follow", "tag", "friend", and "post". By comparison, posts that only contained travel-related or city-related keywords, such as "design", "fashion", "travel", "art", "music", and "food", were less able to resonate with the audience, gaining fewer likes and comments.
For the peri-pandemic posts, posts with more likes contained keywords that prompted positive emotions or feelings, such as "thank", "feel", "together", and "hope", or those that highlighted national image, such as "British", and "England". Posts with more comments contained calls to action, such as "follow", "tag", and "post". By comparison, posts containing only city-related or travel-related keywords, such as "fashion", "travel", "design", "live", "U.K.", "food", and "music", were unable to prompt user demand, consequently gaining fewer likes and comments.

Bangkok
This paper analyzed the posts concerning Bangkok and found that the UGC contained three distinct keyword groups, namely (1) keywords highlighting regional images, (2) keywords prompting positive emotions, (3) and pandemic-related keywords. For the pre-pandemic posts, posts with more likes contained keywords that prompted positive emotion, such as "thank" and "champion". In particular, those that contained keywords about city or regional images, such as "zen", "place", and "temple", were able to attract user attention. By comparison, posts that contained only travel-related keywords, such as "Thailand", "Asia", "hotel", "center", "art", and "amazingthailand", were less able to gain user interest.
For the pre-pandemic posts, posts with more comments contained pandemic-related keywords, such as "follow" and "die". By comparison, posts containing travel-related keywords, such as "food", "central", "travel", "delivery", and "hotel", were less likely to prompt users to comment or like. These observations reiterate our hypothesis that travel-related cues are unable to gain public attention during a pandemic.

Hypothesis Verification
The findings of this study showed that UGC interactivity decreased in various countries during the pandemic. Only content containing pandemic-related keywords gained public attention. By comparison, pre-pandemic city-related UGC containing keywords that prompted positive emotions, those that highlighted local features, and calls to action gained more attention than other UGC [49]. These findings highlight the importance of social involvement in interactivity research [50]. Subsequently, the study of the key behaviors of public involvement can help researchers to understand underlying messages [51,52]. The findings of this study also indicated that, by using social media to promote cities, promoters are able to expand influence through participation [53]. Finally, based on our observations, it is confirmed that the public's city demands are closely associated with community involvement [54].
Posts that contain positive and active keywords are more likely to gain emotional and interactive recognition. The narratives of UGC, which can include cultural, natural, recreational, entertainment, historical, and accommodation dimensions and themes, or attractive, emotional, and cognitive elements [55], significantly influence CI [56]. City researchers can review the attractive elements of UGC [19] to elucidate how UGC shapes and alters CI. Categorizing CI perceptions can also help researchers to uncover content cues [57] and images [58]. Past studies on UGC largely focused on functionality and emotional exchange. Few studies have centered on the relevance of UGC in current events or how positive content cues prompt user involvement [59,60]. To achieve successful CI communication and attract public affirmation and recognition, city promoters should strive to convey a consistent and active CI. Visual elements are an essential part of the clear projection of a sustainable city image, and they give meaning to symbolic signs and present the multifaceted characteristics of the city with the use of various informational symbols. They aim to guide people in tourism decision making, and they also positively impact the perception of the city.

Discussion
Sustainable city communication generally requires public involvement, such as liking, sharing, or commenting on social media posts [61]. Social media can serve as a communication tool between cities and the public. It can enhance city interaction and public trust [62,63] and change people's impression of the city. Therefore, city promoters can take advantage of UGC on social media and the sharing economy to achieve their marketing goals [64]. Given that UGC serves a key function in expressing and enhancing overall public perception [17], it is more important to understand the positive and negative effects of UGC on CI [65,66].
Interactive platforms are built on sharing experiences and to provide users with resources that they need or desire. Social media is gradually replacing traditional media as more users are shifting to social media platforms for their authenticity and personalized features. Raising city awareness prompts travelers to stay in the city longer or participate in local events. It also creates opportunities for interaction and helps travelers to establish a deeper connection with and understanding of the city. Therefore, different backgrounds must be taken into account when planning and creating a presence on social media by combining image management and social media marketing.
According to the literature about information analysis, cities are often characterized by their diverse aspects of culture, food, and entertainment. Whether the information is an adjustment message of UGC or about improving the real-life experience in urban dialogue, it can be translated into the diverse value of UGC marketing. Many Internet users rely on social media to communicate and express their concerns, opinions, beliefs, and genuine perceptions about new things. For example, during the pandemic, the number of tweets with hashtags such as #coronavirus, #COVID-19, or #COVID on Twitter increased exponentially. This phenomenon led to social media platforms, such as Twitter, Facebook, YouTube, and TikTok, to handle misinformation about COVID-19 with a high degree of caution. A high volume of tweets containing panic and worrying information may cause public fear, which in turn affects trust in the government. If such issues persist without the implementation of necessary preventive measures, public distress and fear may increase. Therefore, it is particularly necessary to observe COVID-19-related social media messages to understand people's feelings and opinions during the pandemic.
Under the influence of the pandemic, urban organizations have tried to create new ways of interacting with the public through social media platforms, changing the reactive approach of traditional communication tools. For example, images and text resources on Instagram or recordings and content production using IGTV were adopted to enhance the public's active participation and sharing of their stories. In fact, as the pandemic wanes, it is not difficult to detect that managers, creators, or tourism industries have obtained a lot of interesting results through UGC research. This phenomenon indicates that making full use of UGC can effectively create sustainable value for cities.

Limitations of the Research and Suggestions
Sustainable cues in social media posts can be converted to heuristic information that highlights the characteristics of the commenters. Therefore, this paper recommends analyzing the cues in people's comments or reviews of UGC in the future to assess the credibility of information provided by new and experienced users, and commenters' professional knowledge would greatly affect their comments [67]. Many studies emphasized city personality and focused on city features [68,69]. Therefore, this paper recommends comparing users from different regions or cultures, such as the CI perceptions of people living in the West compared to those living in the East, to determine the differences in demand of information among different groups.