2.1. Water in Biophilic Design
Water has long been regarded as one of the most powerful elements in biophilic design, capable of having a profound impact on human sensory and emotional experiences [
14]. It is widely believed that water features can significantly reduce stress, improve mood, enhance cognitive function, and promote relaxation [
15]. On a sensory level, studies have shown that the flow of water and the rhythm of its sounds provide a space with natural stimulation that is continuously changing yet predictable. This quality can evoke the innate human “affinity for water,” reducing psychological tension, stabilizing emotions, and creating a meditative sense of relaxation [
16]. As Nevzati et al. pointed out, indoor water elements in educational buildings have been shown to reduce stress levels and improve users’ well-being. Their study found that, regardless of gender, users considered the water features at the building entrance to be beneficial [
17]. These water features enhanced the spatial appeal and, in an intangible way, created a “psychological buffer zone” that helped users transition their mental state when entering or leaving the building, thereby reducing fatigue and improving concentration [
18]. Meanwhile, water also plays an important role in environmental regulation. Yang et al. developed a numerical model that combines building energy consumption simulation with computational fluid dynamics to quantify the effects of waterfalls and ponds in public buildings. Their findings showed that water elements such as waterfalls significantly enhanced evaporative cooling in summer, while also improving thermal and humidity conditions and reducing energy consumption [
19]. This suggests that integrating water features with sustainable building strategies is feasible and provides a reference for future climate-adaptive design. In public and outdoor spaces, water features also possess a social–functional attribute. Mador explored the psychological impacts of biophilic design, emphasizing that the presence of water in architectural spaces can enhance residents’ well-being [
20]. At the same time, water features often serve as visual focal points and gathering spots in public areas, supporting functions such as leisure, education, socializing, and cultural activities. They can foster community interaction and a sense of place, thereby enhancing the vibrancy of the area [
21].
As a typical example of large-scale public facilities, sports venues present unique opportunities for the integration of water elements due to their spatial characteristics and usage requirements. In outdoor spectator areas and plaza spaces, fountains, water curtains, and misting systems not only create a sense of ceremony at the venue entrance, but also provide significant cooling and humidity regulation during hot weather [
22]. Some international event main stadiums incorporate interactive water features along major pedestrian thoroughfares [
23]. In the commercial and public amenity areas of a venue, water elements help create gathering nodes, extend visitors’ dwell time, and enhance the operational value of the facility [
24]. As advocated in today’s green building technologies, when combined with rainwater collection, storage, and recycling systems, water features in sports venues can achieve sustainable water supply while beautifying the environment, offering the environmentally friendly and clean attributes of resource reuse, and promoting the sustainable development of sports facilities [
25,
26].
2.2. Natural Design Features of Waterfront Sports Venues and Place Attachment
The natural design features of waterfront sports venues refer to a systematic design strategy that transforms aquatic environments into quantifiable experiential mediums through architectural–ecological synergy [
27]. These features embody an organic integration of built and natural environments, converting water elements into perceptible spatial experiences through methodical design approaches [
28,
29]. Rooted in the intersection of environmental psychology and ecological design theory, this design philosophy aims to create spatial environments with a profound sense of place. In this study, the natural design features manifest through three interrelated dimensions: Natural Visibility, achieved through architectural layout and interface design to ensure visual accessibility of water landscapes; Natural Integration, reflected in the harmonious unity of building materials, formal language, and aquatic environments; and Natural Interaction, facilitated through participatory methods.
Place attachment is defined as a multidimensional, affective–cognitive bond that individuals or groups form with particular physical environments [
30]. It is a comprehensive psychological process whereby a person develops a sense of identification, dependence, and belonging toward a physical space [
31]. This concept originated in psychology and is widely applied in fields such as architecture and urban planning [
32,
33]. Mainstream research believes that place attachment consists of two basic dimensions: place identity, which reflects the extent to which individuals incorporate places into their self-concept system; and place dependence, which measures the uniqueness and irreplaceability of places in meeting individuals’ functional needs [
34,
35]. In subsequent studies, some scholars expanded the dimensional system by adding Affective Attachment and Social Bonding [
36]. The development of place attachment demonstrates a clear temporal accumulation effect. As proposed in Scannell and Gifford’s tripartite framework (person–process–place), the strength of attachment follows a non-linear progression with duration of use: initially stimulated by novelty-seeking behavior, then consolidated through repeated engagement, and eventually sustained by emotional investment and sunk costs [
37]. This developmental pattern is particularly evident in waterfront sports venues [
38]. Early-stage users are typically drawn to the scenic waterside setting, where the visual appeal of the aquatic environment creates initial attraction [
39]. Through regular visits and exercise routines, this superficial interest gradually transforms into deeper functional and emotional connections [
40]. Ultimately, long-term users develop such strong place bonds that they remain attached even when the facilities become outdated or less competitive—a phenomenon demonstrating how place attachment evolves from casual preference to profound dependence. In recent years, place attachment has been regarded as an important mediating variable that influences a series of outcome variables such as user satisfaction, behavioral intentions, and environmentally responsible behavior. It has shown a significant influence in sports, tourism, and leisure venues related to the natural environment [
41,
42].
Environmental psychology research shows that humans have an innate affinity for water bodies. This “hydrophilicity” influences individuals’ perception of space and emotional responses through visual, interactive, and contextual integration [
43].
Therefore, focusing on the natural design characteristics of water areas, this article discusses three key dimensions: First, from the perspective of perception, natural visibility is the most direct way for users to experience the water environment. Empirical research has found that the visual accessibility of water bodies significantly influences users’ psychological responses and sense of place identity. This influence is not only determined by whether one “sees” the water body but is also closely related to perspective, viewing distance, and the continuity of the visual field. For example, Warzecha and Lime’s study in Canyonlands National Park found that visual experiences in natural environments (such as river landscapes) can significantly enhance emotional and functional attachment [
44]. In addition, in urban natural spaces, visual natural elements have been proven to enhance residents’ emotional connection to and frequency of use of the space. For example, Ryan’s study explored the impact of environmental experiences in urban natural areas on place attachment and found that visual contact with nature is a key factor in residents forming emotional connections to a space and influences their usage behavior and attitudes [
45]. Second, visual contact alone is not enough to form a deep emotional connection. Natural integration emphasizes the strength of the relationship between water bodies and architectural spaces and the manner of their integration. When water bodies are only used as decorative elements on the exterior of buildings, their impact is often limited to the aesthetic level. However, when water bodies are integrated into the interior spaces of buildings, they can enhance the sense of place on a cognitive level. Related studies have pointed out that the degree of integration between architecture and the natural environment significantly affects participants’ place loyalty and emotional attachment, which is particularly evident in sports or tourism scenarios. For example, a coastal study in East Tasmania by Jayakody et al. pointed out that the symbiosis between the natural environment and human activity space is a key source of place attachment. Participants emphasized that the “integrative experience” of the natural landscape is one of the main mechanisms for creating emotional connections [
46]. Furthermore, Daneshgarmoghaddam and Bahrainy’s research points out that the spatial integration of natural landscape elements (such as gardens and water bodies) with architecture enhances residents’ sense of identity and belonging to the space, and that the integrated experience improves the perception of environmental quality, which is an important factor influencing place attachment [
47]. Third, natural interaction reflects the process of deepening the experience from passive observation to active participation. In waterfront sports venues, water is not only a landscape element, but also a medium for participation. Its interactive design (such as wading paths, water-friendly platforms, activity areas, etc.) will significantly enhance users’ sense of participation and belonging. Research has shown that visitors engaging in interactive experiences in natural environments, such as water sports and water-based recreational activities, can help strengthen environmental attachment and behavioral intent [
48,
49]. A survey of 717 Scottish open water swimmers found that this natural form of interaction, which involves directly entering the water to engage in activities, not only enhances physical health but also significantly improves mental well-being, social connections, and emotional attachment to the aquatic environment [
50]. Based on this, this paper proposes the following hypotheses:
H1: Natural visibility positively affects place attachment to waterfront sports venues.
H2: Natural integration positively affects place attachment to waterfront sports venues.
H3: Natural interaction positively affects place attachment to waterfront sports venues.
2.3. The Mediating Role of Connectedness to Nature
Nature connectedness refers to the emotional, cognitive, and experiential connection between individuals and the natural environment as perceived by the individuals themselves. It is a core concept in fields such as environmental psychology, ecological architecture, and urban design. Scholars generally believe that nature connectedness is not just a static attitude, but rather a perceptual state that can be activated. Visual contact, physical participation, spatial integration, and emotional responses can all trigger nature connectedness [
51]. A high level of perceived connectedness to nature is closely related to an individual’s sense of well-being, resilience, and willingness to engage in sustainable behavior [
52]. In the field of architecture and spatial design, connectedness to nature is becoming an important way to guide users’ perception of places and the construction of emotions. Architectural scholars have concretized this into a perceptible design language, such as through the use of natural materials, facade openings, changes in light and shadow, guidance of sightlines, and the introduction of water features, to give users a genuine feeling of “natural participation” in the architectural space [
53]. As a typical natural built space intersection, the design and usage characteristics of waterfront sports venues make the perception of connectedness to nature more multidimensional and meaningful. On the one hand, water landscapes have high visual appeal and a calming effect, which helps to enhance the perceived value of the space. On the other hand, sports activities themselves are highly physical, allowing users to immerse themselves in a natural experience through interaction. The higher the degree of integration between architecture and water bodies, the easier it is for users to form a sense of dependence and emotional identification with the space during use. This “active connectedness to nature” has also been proven to be an important mechanism for promoting place attachment [
54].
Visual accessibility is the most direct channel for forming connectedness to nature. In terms of natural visibility, Li et al. conducted an experiment involving participants who could see at least three trees outside their windows and found that a green view outside the window can effectively enhance an individual’s level of connectedness to nature, and that this sense of connection further promotes their emotional state and sense of spatial identity, verifying the smooth logical chain from natural visual accessibility to connectedness to nature to psychological response [
55]. Compared to passive contact on a visual level, the degree of integration between architectural space and the natural environment may further influence the depth and sustainability of connectedness to nature. When natural landscapes are not only visual objects but are also incorporated into architectural structures, forming spatial interaction and integration, users are more likely to establish a stable and profound experience of connectedness to nature [
56]. As Duffy points out, when natural elements such as green walls, open spaces, and natural lighting are integrated into building structures, they can more directly promote connectedness to nature while improving health and well-being [
57]. Connectedness to nature does not only come from viewing or perception, but can also be continuously strengthened through physical participation and interaction with the natural environment. In waterfront sports venues, water activities and water-friendly paths provide users with opportunities for interaction with nature. This proactive experience of nature helps to enhance their sense of connectedness to nature and further transforms into emotional attachment to the place. As one study points out, providing water–enjoyable–space designs in urban waterfront spaces, such as shallow beaches, walkways, and water play areas, helps stimulate people’s sensory engagement and psychological satisfaction with water bodies, enhances emotional interaction with nature, and promotes the formation of place attachment [
58].
The dual-process theory states that human thinking and behavior are driven by two different processing systems. This theory was first proposed by psychologists to explain how humans make judgments and decisions when faced with complex information. Its core idea is that human cognition is not a single process, but rather two interacting systems: fast intuition and slow rationality [
59]. On the one hand, people rely on a fast, automated intuitive system to respond instantly to their surroundings (System 1); on the other hand, they also activate a slow, thoughtful rational system for more complex cognitive processing (System 2). This dual mechanism enables humans to respond quickly to environmental changes while also engaging in deep thinking [
60]. In the field of environmental psychology, this theory is particularly useful in explaining how people connect with the natural environment through different psychological pathways and form emotional attachments to specific places.
From a System 2 perspective, the formation of connectedness to nature often requires a gradual process. When individuals repeatedly encounter natural elements in a specific place, they gradually establish a psychological connection with the natural environment through conscious cognitive processing [
61]. Take waterfront sports venues as an example. Through continuous exercise, users will gradually recognize the positive impact of the aquatic environment on their exercise results and mental state. This rational understanding will promote the establishment of connectedness to nature. Based on this, this paper proposes the following hypotheses:
H4: Connectedness to nature mediates the effect of natural visibility on place attachment.
H5: Connectedness to nature mediates the effect of natural integration on place attachment.
H6: Connectedness to nature mediates the effect of natural interaction on place attachment.
2.4. The Mediating Role of Biological Affinity
Biological affinity refers to the innate attraction and emotional connection that humans have to natural life forms and ecosystems [
62]. This concept originates from the biophilia hypothesis proposed by Edward O. Wilson in 1984, which posits that humans have developed a deep psychological need for natural environments during the course of evolution. Its core tenet is that humans have an instinctive positive response to natural elements such as green plants, water bodies, and sunlight. This response is rapid and automatic, capable of eliciting emotional changes without conscious thought [
63].
Biological affinity plays a key role in the relationship between humans and the environment. In the process of forming natural elements and place attachment, in recent years, many studies have shown that visual, auditory, and physical contact with natural elements can stimulate biological affinity, thereby influencing people’s emotional attachment to specific places.
From the perspective of natural visibility, Mousighichi et al. surveyed 378 college students to assess how their visual, physical, and auditory connections with nature affected their place attachment and quality of life. The results showed that visual connectedness to nature (such as natural light, greenery, and natural views) was significantly associated with students’ sense of place dependence and physical health, while auditory connectedness to nature had a greater impact on place identity. This suggests that the visual accessibility of nature enhances people’s emotional connection and identification with a space by stimulating biological affinity [
64]. Similarly, Hung and Chang’s research shows that visual natural features stimulate positive emotions and are highly correlated with people’s identification with and fondness for a place [
65].
From the perspective of natural integration, a study organized focus groups to discuss community residents’ views on natural integration urban design in the context of a proposed biological affinity urban renewal project in Wales, UK. The results showed that community members expressed high expectations for the integration of nature into space in terms of the history, identity, and future vision of the site. The “structural integration” of nature helps to strengthen the identity of the place and stimulate “place emotions from a biological affinity perspective” [
66]. Gasaymeh’s research indicates that incorporating natural elements into public buildings can significantly enhance users’ emotional satisfaction and sense of attachment to the place [
67].
From the perspective of natural interaction, Cole theoretically explored how biological affinity strategies in green buildings affect users’ emotional attachment to a place, functional dependence, and sense of identity. Cole pointed out that biological affinity is not just aesthetics. Through the emotional interaction between nature and people, it promotes people to regard “natural buildings” as places where they have a sense of belonging and identity, thereby strengthening place attachment [
68]. Similarly, Cengiz and Boz studied how children’s physical interaction with nature in “biological affinity playgrounds” promotes environmental identification and emotional attachment. The study pointed out that children’s free play with natural materials such as water, soil, stones, and trees naturally stimulates a sense of “exploratory biological affinity,” which further guides their attachment to the playground [
69].
System 1 (intuition/emotion system) of the dual-process theory is a fast, automatic cognitive processing mode that relies on intuition, emotion, and instinctive reactions and can be completed without conscious effort [
61]. In other words, the natural elements in waterfront sports venues can directly evoke users’ instinctive biological affinity responses, because biological affinity is a natural human tendency toward nature [
70]. When users first enter the venue, the expansive view of the water immediately triggers visual pleasure. This positive emotional response to the water landscape is immediate and automatic, requiring no conscious thought whatsoever [
71].
Similarly, when architectural design seamlessly integrates with aquatic environments, users instinctively experience the comfort derived from this harmonious relationship. For instance, the design of waterfront platforms naturally draws people closer to the water. During use, if the venue provides opportunities for interaction with water, such as water sports facilities or waterfront recreation areas, this direct physical contact will further strengthen the instinctive connection between users and the natural environment. This instinctive response based on biological affinity forms the initial basis for users to establish an emotional connection with waterfront sports venues. In other words, the natural visibility features of the venue activate users’ instinctive preference for water, providing an emotional basis for the subsequent formation of place attachment; natural integration strengthens this emotional connection by satisfying users’ primal need for a harmonious environment; and natural interaction deepens positive feelings on an instinctive level through direct personal experience. Based on this, this paper proposes the following hypotheses (the proposed model diagram is shown in
Figure 1):
H7: Biological affinity mediates the relationship between natural visibility and place attachment.
H8: Biological affinity mediates the relationship between natural integration and place attachment.
H9: Biological affinity mediates the relationship between natural interaction and place attachment.