4.1. Summary of Key Findings
This study examined the relationships among spatial perception, perceived restorativeness, environmental sensitivity, and residents’ well-being along the Nanjing Yangtze Riverfront. By operationalizing spatial perception as a multidimensional construct, this study contributes to research on urban blue–green infrastructure and well-being, offering an integrative person–environment perspective consistent with restorative environment theories.
SEM results indicated that spatial perception was positively associated with perceived restorativeness (H1: β = 0.320, p < 0.001), and perceived restorativeness was positively associated with residents’ well-being (H2: β = 0.540, p < 0.001). Given the cross-sectional, single-source self-report design, these estimates are interpreted as associations consistent with the proposed restorative process, rather than definitive causal effects. Mediation analysis further supported partial mediation (H3), with an indirect effect of β = 0.173 (95% bootstrap CI [0.105, 0.259]) accounting for 41.69% of the total effect. Moderation analysis revealed a statistically significant positive interaction (H4: β = 0.799, p < 0.001), indicating that the spatial perception–restorativeness association was stronger among individuals with higher environmental sensitivity, consistent with the hypothesized direction. The model accounted for a moderate proportion of variance in well-being (R2 = 0.434); however, this level of explained variance should be interpreted cautiously in light of potential shared-method variance and conceptual proximity among self-report constructs, despite the measurement diagnostics conducted to assess discriminant validity and common method bias.
Before examining the theoretical implications in detail, it is important to situate these findings within the broader context of blue–green infrastructure research and acknowledge the cultural and geographic specificity of the Nanjing riverfront setting. Urban riverfront regeneration in China often involves the concurrent pursuit of ecological restoration, cultural heritage preservation, and rapid urban development within relatively compressed timeframes. The Nanjing Yangtze Riverfront exemplifies this pattern, with segments integrating industrial heritage (e.g., Pukou), natural/geological features (e.g., Qixia), and contemporary recreational infrastructure (e.g., Jianye) within a single metropolitan waterfront system. This context may shape the salience and interpretation of specific spatial qualities.
The prominence of aesthetic perception as the strongest predictor of restorativeness (β = 0.265) may partly reflect context-dependent aesthetic norms and planning practices that influence how residents evaluate curated riverfront environments. Conversely, the comparatively modest association between safety perception and restorativeness (β = 0.204) may indicate that safety concerns are less salient for everyday riverfront use in this context; however, this interpretation remains context-specific and would benefit from corroboration using objective indicators (e.g., safety incident records, lighting/visibility audits, or perceived safety heterogeneity across segments). The segment-level variation further highlights that “urban riverfront” is not a uniform category but comprises diverse typologies with potentially distinct restorative affordances. The strong performance of both culturally embedded segments and naturalistic segments suggests that cultural meaning-making and ecological authenticity may both contribute to restorative appraisals—potentially through partially distinct pathways—rather than functioning as mutually exclusive sources of restorative potential. Overall, the findings are best interpreted as evidence of general relational patterns within a specific socio-cultural setting, and direct transferability to other geographic and cultural contexts should be treated cautiously.
4.2. Theoretical Implications
4.2.1. Spatial Perception and Perceived Restorativeness (H1)
The positive association between spatial perception and perceived restorativeness is consistent with core propositions in environmental psychology that emphasize perceptual appraisal as a key pathway through which environmental characteristics relate to psychological outcomes [
4,
5]. In the present model, the standardized association was moderate (
β = 0.320), indicating that spatial perception explains approximately 10.2% of variance in perceived restorativeness. Riverfront environments that combine water, vegetation, and open views may plausibly enhance restorative appraisals. The magnitude of this coefficient is within the typical range observed in environmental psychology research and is less likely to be inflated by shared-method variance compared to higher estimates sometimes reported in single-source studies. Accordingly, the estimate is interpreted as evidence of a meaningful positive association consistent with theoretical expectations [
14,
15,
44].
At the dimensional level, Aesthetic Perception showed the largest standardized association with perceived restorativeness (
β = 0.265), followed by Accessibility Perception (
β = 0.221) and Safety Perception (
β = 0.204). These patterns are broadly consistent with Attention Restoration Theory (ART) [
11], which posits that restorative environments support recovery through qualities that attract effortless attention and provide an interpretable, supportive setting. The prominence of aesthetic perception aligns with ART’s emphasis on fascination, whereby visually engaging scenes facilitate “soft fascination” and thereby support recovery of directed attention [
11,
12]. The associations of accessibility and safety with restorativeness are also theoretically plausible: environments that are easy to approach and navigate, and that are perceived as secure and comfortable, may strengthen perceived compatibility (fit with intended activities) and the experience of extent (the sense of coherent scope), thereby supporting restorative appraisal [
11,
45].
The findings are also compatible with Stress Reduction Theory (SRT) [
13], which highlights rapid affective and physiological responses to natural settings. From an SRT perspective, favorable spatial attributes in riverfront landscapes may promote positive affect and reduce stress-related arousal, which can manifest as higher perceived restorativeness [
13,
46]. Taken together, the results support the practical value of integrating ART and SRT in a unified framework, as suggested in prior scholarship [
14,
27], while underscoring the importance of interpreting the strength of associations in light of measurement and design characteristics.
4.2.2. Perceived Restorativeness and Well-Being (H2)
The positive associations between perceived restorativeness and residents’ well-being across all four outcome dimensions (stress reduction, mood enhancement, place attachment, and life satisfaction) are consistent with prior work demonstrating the psychological benefits associated with restorative environments [
5,
6,
8]. In the present study, perceived restorativeness showed a substantial positive association with overall well-being (
β = 0.540,
p < 0.001). Given the conceptual proximity among self-report well-being indicators and the cross-sectional single-source design, this coefficient is interpreted as indicating a meaningful linkage between restorative appraisal and well-being facets [
17,
18,
47].
The comparatively strong linkage with place attachment is theoretically plausible and aligns with perspectives emphasizing that psychologically beneficial environments can foster meaningful person–place bonds that are themselves implicated in well-being [
19,
20,
21]. Prior studies have shown close connections between restorative experiences and place-based relationships (including potential reciprocal dynamics) [
17]. Extending this literature, the current model positions place attachment as a salient well-being-related outcome associated with perceived restorativeness within an integrated framework, while underscoring the need for longitudinal or multi-source designs to clarify temporal ordering and causal direction.
4.2.3. Mediation Effect of Perceived Restorativeness (H3)
The mediation results support perceived restorativeness as a partial mediator linking spatial perception to well-being (indirect effect = 0.173; proportion mediated = 41.69%), which is consistent with integrative models emphasizing perceptual appraisal and restorative processing as key pathways from environmental experience to psychological outcomes [
14,
17,
31]. The presence of partial mediation suggests that restorative appraisal constitutes an important—but not exclusive—mechanism through which spatial environmental perceptions relate to well-being, implying that additional pathways (e.g., affective responses, activity engagement, social interaction, or place-related meanings) may also contribute. This interpretation aligns with prior evidence that perceived restorativeness can transmit the influence of environmental features to mental health-related outcomes in other settings [
44].
The observed mediated proportion (41.69%) is broadly comparable to values reported in related studies on urban nature contexts, while not necessarily implying direct cross-study equivalence due to differences in settings, measures, and model specifications. For example, Peschardt and Stigsdotter [
48] reported mediation proportions above 40% in an urban park context. One plausible implication is that riverfront environments may involve additional experiential components beyond those typically captured by conventional restorative constructs. In particular, water-related features could introduce sensory and symbolic cues—such as visual dynamics, acoustic qualities, and culturally embedded meanings—that may shape well-being through complementary pathways [
9,
49]. These possibilities remain inferential in the present study and warrant targeted measurement and longitudinal or multi-source designs to clarify mechanisms and temporal ordering.
A fundamental limitation of the mediation analysis is the cross-sectional design. While the hypothesized perception–restorativeness–well-being sequence is theoretically grounded in ART and SRT and receives statistical support in the present data, temporal ordering cannot be verified from cross-sectional data alone. Reverse or reciprocal pathways are also plausible: individuals with higher baseline well-being may appraise environments more favorably, leading to higher perceived restorativeness and more positive spatial perceptions, and place-related meanings may co-evolve with well-being through repeated visits and accumulated experiences. Accordingly, the mediation results should be interpreted as evidence of theoretically consistent associations and a plausible explanatory mechanism rather than definitive proof of causal directionality.
4.2.4. Moderation Effect of Environmental Sensitivity (H4)
The moderation analysis indicated that environmental sensitivity significantly moderated the spatial perception–restorativeness association (β = 0.799, p < 0.001), with a substantial effect size (R2 = 0.655). Consistent with the hypothesized strengthening effect, the positive coefficient suggests an amplification pattern, whereby the positive association between spatial perception and perceived restorativeness becomes stronger at higher levels of environmental sensitivity. This finding supports environmental sensitivity as a meaningful boundary condition that enhances the perception–restoration pathway.
Simple-slopes analysis revealed a notable pattern: at high environmental sensitivity (+1 SD), spatial perception was strongly positively associated with perceived restorativeness (β = 0.936, p < 0.001), whereas at low environmental sensitivity (−1 SD), the association was negative (β = −0.529, p < 0.001). This crossover interaction suggests that environmental sensitivity fundamentally shapes how individuals translate spatial perceptions into restorative appraisals. For highly sensitive individuals, favorable spatial qualities substantially enhance restorative experiences; for less sensitive individuals, spatial perception alone may be insufficient or even inversely related to restorativeness, possibly because highly structured or ‘over-designed’ environments may paradoxically increase cognitive load for individuals who prefer low-arousal or more ‘wild’ natural settings, rather than providing the expected restoration.
This finding aligns with theoretical perspectives suggesting that environmentally sensitive individuals are more attuned to and responsive to environmental stimuli, including both positive and negative qualities [
23,
31]. From an Attention Restoration Theory perspective, highly sensitive individuals may more readily perceive and benefit from the fascination, extent, and compatibility qualities embedded in well-designed riverfront spaces [
11,
12]. From a practical standpoint, this result suggests that spatial-design improvements may produce particularly strong restorative gains for environmentally sensitive users, while less sensitive individuals may require complementary interventions (e.g., programmatic activities, social facilitation, or multisensory engagement) to achieve comparable restorative outcomes [
4,
6].
From a building science perspective, this necessitates the creation of ‘Quiet Zones’ or sensory-friendly micro-spaces within riverfront parks. Prioritizing the needs of these sensitive groups is not merely a design preference but a matter of social sustainability and environmental justice, ensuring that urban infrastructure supports the mental health of all residents, including neurodiverse populations. From an urban resilience perspective, this necessitates a move toward “Neuro-inclusive Design.” Riverfronts should incorporate “Sensory Refuges”—sub-spaces with low-density planting, acoustic buffering from city noise, and non-reflective materials. By designing for the most sensitive 20% of the population, we inherently create more comfortable environments for the remaining 80%. This aligns with the broader goals of Social Sustainability within the Buildings framework, ensuring that blue–green infrastructure serves as an equitable public health resource rather than a source of sensory overload.
Beyond the design implications discussed above, the crossover pattern requires deeper theoretical interpretation. The negative slope at low environmental sensitivity challenges conventional restorative environment theory and suggests that spatial perception alone may be insufficient or counterproductive for individuals with low environmental attunement. From a cognitive load perspective, highly structured or visually complex riverfront environments may impose processing demands exceeding the cognitive resources or motivation of low-sensitivity individuals. For these users, elaborate spatial design elements intended to enhance aesthetic appeal may paradoxically increase perceptual burden rather than facilitate restoration, particularly if they prefer simpler, less visually demanding natural settings. Alternatively, the negative association may reflect preference-mismatch effects. Low-sensitivity individuals may prioritize functional attributes over perceptual-aesthetic qualities. When spatial perception emphasizes visual aesthetic dimensions without addressing functional needs, these users may experience reduced satisfaction and lower restorative appraisal. While the interaction was tested using mean-centered continuous variables appropriate for linear interactions, this approach may not fully capture threshold effects or nonlinear relationships across the full sensitivity spectrum that could further clarify this unexpected pattern.
4.2.5. Differentiated Spatial Perception Characteristics of Riverfront Segments
The one-way ANOVA results reveal significant spatial heterogeneity in residents’ perceptions and well-being outcomes across the six riverfront segments. Based on the mean scores (M), the segments can be categorized into three distinct performance tiers:
S5 (Pukou Segment): Data indicate that S5 (Pukou Segment) ranks highest in both spatial perception (M = 3.862) and environmental sensitivity (M = 3.825). This underscores the unique appeal of the ‘Industrial Heritage + Natural Wetland’ model. The Pukou segment preserves historically significant industrial cultural landscapes while integrating them with ecological wetlands through recent urban renewal. This synergy provides high visual complexity and a sense of cultural belonging. Additionally, the large area of waterfront exposure in this segment, with expansive river views, likely contributes to its high scores in spatial perception and perceived restorativeness, enhancing the sense of fascination and extent. Such an ‘interwoven’ spatial character reinforces the restorative qualities of the riverfront environment, aligning with Attention Restoration Theory’s emphasis on visual engagement and ‘soft fascination’.
S3 (Gulou Segment): This segment, featuring the Muyan Riverside Scenic Area, demonstrates the strongest impact on restorativeness (M = 3.820). This performance can be attributed to its profound cultural heritage and excellent accessibility in the city center, facilitating a seamless transition between the ‘fast-paced city’ and ‘slow-paced nature,’ thus providing an ideal psychological buffer for residents.
- 2.
Balanced Restorative Zones: S2 (Jianye) and S4 (Qixia)
These two segments exhibit stable restorative functions with relatively similar mean scores across dimensions (M≈3.6–3.7).
S2 (Jianye Segment): Leveraging high green coverage and sophisticated infrastructure—including the Yuzui Wetland Park and Green Expo Park—this segment shows the highest well-being score (M = 3.809), functioning as a mature ‘urban living room’ that effectively meets the recreational needs of high-intensity workers.
S4 (Qixia Segment): The segment likely performs better in perceived restorativeness (M = 3.799) due to the presence of landscape environments like Yanziji Park, which allow for close interaction with water.
This suggests that primordial natural landscapes possess significant physiological advantages in alleviating attention fatigue.
- 3.
Potential Improvement Zones: S1 (Jiangning–Yuhua) and S6 (Luhe)
These segments show relatively lower scores across most indicators (M ≈ 3.4–3.5).
S1 (Jiangning–Yuhua Segment): Despite its rich ecological resources, its functional orientation toward ecological protection may lead to lower perceived accessibility and insufficient facilities. This potentially restricts deep interactive experiences for general residents.
S6 (Luhe Segment): This segment recorded the lowest scores in spatial perception (M = 3.518) and environmental sensitivity (M = 3.421). This is primarily limited by its peripheral geographic location and homogenous landscape functions. Although it possesses a natural foundation, the lack of social interaction elements and convenient transportation support means that while it satisfies the Being Away dimension, its effect on overall subjective well-being remains weak.
4.3. Practical Implications
The findings translate into several actionable implications for riverfront planning, design, and management. Importantly, the results should be read as priorities for enhancing perceived restorative quality rather than as deterministic design rules, because restorative outcomes are shaped jointly by physical form, use patterns, and users’ subjective appraisal.
Aesthetic perception showed the largest standardized association with perceived restorativeness (
β = 0.265), indicating that visual quality is not a “decorative add-on” but a functional driver of restorative appraisal in riverfront settings [
25,
29,
50]. In practice, this implies focusing on a view-based design logic: (i) identify and protect key sightlines to water, skyline, vegetation mosaics, and landmark elements; (ii) organize a coherent “visual sequence” along the promenade (foreground–midground–background layering), reducing abrupt visual clutter; and (iii) curate plant structure, seasonal change, and material palettes to strengthen legibility and scenic continuity. Beyond static beauty, designers can enhance “dynamic aesthetics” through water-edge detailing, planting that responds to wind/light, and designed micro-vistas that periodically reward walking and slow exploration, thereby increasing the likelihood that users experience soft fascination and restorative appraisal.
- 2.
Treat accessibility as both spatial connectivity and experiential usability.
Accessibility perception (
β = 0.221) emphasizes that restorative potential depends on how easily residents can reach, understand, and comfortably use riverfront spaces, not merely whether blue–green elements exist [
30,
51]. Design strategies can be operationalized at three levels: (i) network level—continuous walking/cycling loops with minimized “break points,” clear connections to surrounding neighborhoods, and integration with public transport stops; (ii) site level—multiple entry points, barrier-free routes, readable junctions, and consistent wayfinding that supports first-time visitors and older adults; (iii) experience level—micro-scale comfort that sustains longer stays (shade, seating variety, rest nodes, and clear activity zoning), which can indirectly strengthen perceived restoration by allowing users to engage without friction. In management terms, maintaining route continuity during construction or seasonal flooding and communicating detours clearly can help preserve perceived accessibility even when physical conditions fluctuate.
- 3.
Make perceived safety a baseline condition for restoration, combining design and management.
Safety perception (
β = 0.204) highlights that users are unlikely to benefit restoratively if they feel uncertain or threatened, even in visually attractive environments [
52]. Riverfront interventions should therefore address both objective and subjective safety: lighting continuity, avoidance of hidden corners, improving sightlines at vegetation edges, and maintenance that signals stewardship. At the same time, perceived safety can be strengthened through legible spatial organization (clear routes, identifiable nodes) and “natural surveillance” opportunities supported by appropriate activity distribution. Operational measures—such as routine cleaning, rapid repair of damaged facilities, and visible but non-intrusive management presence—often have outsized effects on perceived safety relative to cost.
- 4.
Use spatial scale and boundary design as context-sensitive refinements rather than single-point fixes.
Although spatial scale (β = 0.155) and boundary perception (β = 0.168) were significant, their smaller coefficients suggest they may function as enabling conditions that interact with other qualities (e.g., aesthetics and safety) and depend on site morphology. Rather than attempting large-scale reconstruction, design teams can adopt incremental tactics: modulating enclosure and openness through planting height gradients, creating transitional “soft edges” between water and path where feasible, clarifying the boundary between movement corridors and stay areas, and avoiding abrupt edge conditions that reduce comfort. These refinements can improve spatial clarity and comfort without major structural change.
- 5.
Apply a people-centered lens: restorative gains may differ across user groups, so pair “universal design” with targeted interventions.
The moderation results suggest that users differ in how strongly spatial perception translates into restorative appraisal [
4,
22]. Given the small interaction magnitude, the implication is not to segment the public rigidly, but to recognize modest heterogeneity and design for broad benefit. For more environmentally sensitive users who are particularly responsive to spatial quality design improvements in aesthetics, accessibility, and safety, may yield substantial restorative gains. For less sensitive users, clear entry sequences, comfortable activity settings, and highly legible scenic routes, along with complementary programmatic interventions, may be especially important in eliciting restorative appraisal. For more sensitive users, design and management may need to reduce multisensory irritants (e.g., crowding hotspots, thermal discomfort) and support quieter micro-settings, which may complement the spatial perception attributes captured here.
- 6.
Combine physical upgrades with programming that increases nature connection and inclusive participation.
Because well-being outcomes emerge from repeated exposure and meaningful engagement, programmatic strategies can amplify design investments. Community events, interpretive signage, and low-threshold activities that encourage residents to notice seasonal and ecological changes may help broaden restorative benefits, especially for those less predisposed to engage with nature [
6,
53]. Such “soft interventions” are often scalable and can be iterated quickly, providing an implementation pathway alongside capital-intensive waterfront upgrades.
4.5. Methodological Contributions
This study incorporated several methodological checks intended to strengthen measurement quality and to address concerns commonly raised in self-report, cross-sectional research on restorative environments. First, discriminant validity was evaluated using the heterotrait–monotrait ratio (HTMT) in addition to the traditional Fornell–Larcker criterion, providing a more stringent assessment when constructs are theoretically adjacent [
43]. As shown in
Table 11, some HTMT values exceeded the conservative 0.85 heuristic but remained below 0.90, which is frequently used as a practical upper bound for conceptually related constructs. Taken together, the HTMT pattern suggests that the constructs are closely associated yet remain sufficiently distinguishable for hypothesis testing. At the same time, the elevated HTMT values indicate partial overlap, and therefore the results are interpreted with appropriate caution—placing emphasis on effect sizes, consistency across analyses, and theoretical plausibility rather than relying solely on statistical significance.
Second, common method bias was assessed using complementary procedures recommended in the literature [
40]. To provide a more rigorous diagnostic, we further applied an unmeasured latent method construct (ULMC) approach. The ULMC results were more reassuring: the average substantive loading substantially exceeded the average method loading, yielding a substantive-to-method ratio of 4.15:1, well above the recommended 2:1 guideline. Together, these checks suggest that although common method variance cannot be fully ruled out in a single-wave self-report design, it is unlikely to be the sole explanation for the observed relationships. Accordingly, the findings are presented as correlational evidence and should be further validated using multi-source and/or longitudinal designs.
4.6. Limitations and Future Research Directions
The perception–restorativeness–wellbeing framework proposed and tested in this study is best suited to specific types of contexts and populations. The model’s applicability is likely strongest in urban blue–green infrastructure settings where: residents have regular, voluntary access to waterfront environments and discretion over visit timing and duration; environmental quality varies sufficiently across sites or temporal conditions to enable perceptual differentiation; the cultural context supports recreational use of waterfront spaces as legitimate health-supporting resources; and basic safety and accessibility thresholds are met. The model may have limited applicability in contexts where these conditions do not hold—for instance, in settings where severe environmental hazards, such as extreme pollution or natural disasters, override perceptual–restorative considerations, in compulsory exposure situations where agency is constrained, or in highly homogeneous environments where spatial quality shows insufficient variance. Additionally, the model emphasizes active engagement with spatial-perceptual qualities and may be less applicable to populations with limited mobility or cognitive capacity to process environmental cues, for whom other restorative mechanisms, such as social interaction or auditory stimuli, may be more salient. The Nanjing study context represents conditions favorable for the proposed model, where the cultural heritage and strong community engagement with the riverfront have shaped residents’ interaction with the environment. Generalization to other riverfront contexts should consider these contextual preconditions and the potential for cultural variation in the salience of specific spatial dimensions and pathways to well-being. For example, in other cultural settings, the emphasis on aesthetic and natural elements may differ, and recreational activities may be less integrated into the urban design, limiting the model’s general applicability.
Several considerations delimit the scope of the present findings and suggest directions for further research. First, the cross-sectional design supports inference about associations rather than temporal ordering. While the proposed perception—restorativeness—well-being pathway is theory-consistent, alternative or reciprocal relationships cannot be ruled out. Future longitudinal or panel designs would be valuable for clarifying temporal dynamics and strengthening causal interpretation [
54].
Second, although this study employed a hybrid sampling strategy that included on-site paper-based questionnaires (21.78%) to mitigate digital bias and improve the inclusion of elderly residents, the use of convenience and snowball sampling still limits population-level representativeness. While the demographic profile (
Table 2) aligns with typical urban park user patterns in Nanjing, future studies should employ stratified or quota-based sampling to further enhance generalizability across diverse socio-economic groups.
Third, the study relies primarily on self-reported measures. Although multiple measurement diagnostics (e.g., HTMT, ULMC) were applied to address common method bias, future research could enhance robustness by triangulating self-reports with objective environmental assessments (e.g., GIS-based greenness indices or site audits) and physiological indicators of stress recovery [
40,
55].
Fourth, the empirical setting is a single city. Because riverfront meanings and cultural practices can vary significantly, comparative multi-city research would help test the boundary conditions and assess the transferability of the proposed model to different geographic and cultural contexts [
49,
56].
Finally, while the current spatial perception instrument focuses on visual–spatial dimensions, future research could broaden the framework to include multisensory aspects (e.g., acoustic comfort and thermal environment) and time-varying factors (e.g., seasonal changes), potentially revealing more complex mechanisms underlying the riverfront restorative experience [
15,
57].