3.1. Textual Theme Structure and Sentiment Results
User comments from platforms including Weibo, Ctrip, Qunar, and Dianping were collected as corpus material. After deduplication and cleaning, a dataset comprising 1575 Chinese online comment texts about “Hanzheng Street” was compiled to construct the Hanzheng Street Urban Memory Text Corpus. Most of the comments use everyday language and show strong feelings. After analyzing the sentiment of all comments, the sentiment results show that 69.59% of the comments are positive, 25.84% are negative, and 4.57% are neutral (
Figure 5). Overall, the sentiment is mostly positive, but some negative feedback remains. An LDA model was used to extract themes from comments across multiple platforms. Theme coherence was measured with Gensim’s c_v metric. Coherence scores were compared for
K from 2 to 15. At
K = 5, coherence increased clearly, and the theme boundaries were clearer, so K was set to 5.
The extracted keywords were merged with their synonyms. Related comment snippets were checked by hand to make sure the theme keywords fit the context. Each theme was named by hand based on the checked theme keywords combinations and representative original comments. Theme names were discussed and checked internally to ensure they align with the intended meaning of the theme keywords. For example, the high-weight words in Theme 1 are mostly about clothes, wholesale market, cheap, small commodities, and daily life. This suggests a scene of buying and selling on the street. This matches the everyday shopping stories in the comments. For this reason, Theme 1 is called “Local Memories.” The other themes were named in the same way: first by looking at the high-weight words, and then by checking the comment context. Ultimately, five core memory structures were identified (
Table 6). To further compare the differences in sentiment across themes, the proportions of positive, neutral, and negative comments under each theme were calculated (
Figure 6).
The table shows that Local Memories and Urban Renewal are the main themes of discussion. The remaining three Themes together account for approximately 51% and point more directly to specific lived experiences and governance-related demands. The cross-analysis of sentiment and Themes indicates that the comments under People-Friendly and Fashion & Commerce contain relatively high proportions of positive sentiment, while negative evaluations in both Themes are around 20% (
Figure 6). This suggests that the public generally recognizes the district’s performance in terms of service quality and image renewal. Negative evaluations of Urban Renewal and Market & Transportation are both around 30%, which is above the average.
3.2. Problem Identification and Visualization Intervention
According to the translation criteria established in
Section 2.4, this research translated the major public demands extracted through the two-stage GPT-4o process as the basic materials for problematisation (see
Supplementary File S1 for detailed data). By using the human actor-theme intensity matrix to identify the behavioral subjects related to demand expression in the comments (
Figure 7), the results show that different public demands correspond to different types of human actors. The urban image elements indicated by the major public demands were then identified, and the relevant spatial objects were mapped onto the five elements of urban image.
Based on the demand extraction data generated by GPT-4o, five experts from relevant fields were invited to conduct two rounds of assessment to determine the final OPPs, and the expert information was recorded using anonymous codes (
Table 7). After reviewing the uniformly organized theme materials, the experts assessed the conflict relationships under each theme and proposed their own candidate OPPs (see
Supplementary File S1 for detailed data).
On this basis, this research summarized the candidate OPPs proposed by the experts and organized a second round of scoring for each OPP. After the scoring was completed, this research used the mean scores excluding self-evaluations as the basis for ranking the candidate results and adopted Kendall’s coefficient of concordance to test the consistency of expert scoring. The results show that the overall Kendall’s W for expert scoring was 0.557, with
p < 0.001, indicating a relatively good level of overall consistency in expert judgments (see
Supplementary File S1 for detailed data). Therefore, this research selected the candidate result with the highest mean score under each theme as the corresponding OPPs and further mapped it to the elements of urban image (
Table 8).
Although the spatial elements and problem emphases corresponding to each theme differ, they all point to the coordination among spatial function organization, improvement of street-block experience, and diverse public demands. Therefore, this research further consolidated them into a core issue: the alignment between Hanzheng Street’s current spatial functions and street-block experience and the public’s diverse everyday life and emotional needs.
The OPPs and core issue identified in the preceding analysis were then operationalized into specific spatial units. This research constructed a candidate scene library from 96 photographs taken during the field investigation, which were independently screened by two researchers according to a unified evaluation form (see
Supplementary File S1 for detailed data). According to the evaluation results, 34 of the 96 candidate photographs entered the redundancy screening stage, whereas the remaining 62 were excluded during the initial screening. The samples entering the next round showed a relatively high overall level of suitability. The samples entering redundancy screening were further compared for duplication, and where spatial characteristics, problem orientation, and observed content were highly similar, the more representative photograph was retained. After redundancy removal, 17 duplicate samples were excluded from the 34 photographs, resulting in 17 scene units for subsequent renewal generation and public evaluation.
This research reorganized the obtained data into an eight-slot template for direct input into GPT-4o, covering memory weights, spatial problems, renewal needs, and output constraints. The “Weighted Summary” aggregates the proportion of five thematic content categories and their corresponding sentiment distributions, determining priorities for “high-impact” and “high-priority mitigation” actions.
In this setup,
Ai is the comment proportion for the i theme.
Ni is the negative emotion proportion for that theme.
Nall stands for the overall negative emotion baseline.
K is the total number of themes. The formula below calculates the average theme proportion:
This research identifies 5 themes in total, and the
Nall value is 25.9% (
Figure 5). Therefore, the average theme proportion and the overall negative emotion baseline are written as:
The rules for determining memory weights are as follows:
If a theme has a higher percentage of comments than the average for themes, then the theme’s content in the prompt words will be prioritized.
If the negative sentiment pressure of a theme exceeds the overall average, it is given priority in the mitigation content of the prompt.
When both of the above conditions are met, the theme shows both high salience and strong problem pressure. It therefore serves in the prompt as both a key focus of expression and a priority target for mitigation.
The spatial problems and renewal demands are then translated into descriptive text, as shown in
Table 8. The prompt generation rules directly use the content from
Table 5. This structure is used to generate constrained prompts with the GPT-4o API, and it works with Stable Diffusion and scenario units to produce renewal renderings. First, GPT-4o is required to parse the current semantics of scene units and then make an objective description one by one according to the specified slot table. Then, based on the memory weights and instruction text, renewal text prompts were generated within the limits of the constraint slots. The scene unit first provides an objective description of the eight slots based on their current semantic state. Then it reads the memory weights and uses the constrained slots to generate a light, low-impact action text without adding more content. The final result is a description of the scenario unit now and a list of image-to-image prompts for Stable Diffusion. In this research, all instructions and prompts generated by calling the API will be archived and recorded (see
Supplementary File S1 for detailed data).
Input the generated prompts and their corresponding on-site scene unit photos into Stable Diffusion one by one. Seventeen updated renderings of Hanzheng Street were generated, with the same perspective and consistent scene meaning. Stable Diffusion’s underlying generative model uses the architecturerealmix_v11 architecture. ControlNet controlled the lines (Canny) and depth. This makes sure the generated images match the structure of the original photos. The key parameters used during the generation process were also recorded and archived in
Supplementary File S1. To show the before-and-after differences of the scenario units more clearly in the questionnaire, this research presents representative samples side by side (
Figure 8).
3.3. Acceptance and Feasibility Assessment
These were subsequently rewritten based on the five OPPs and the core issue obtained in the problematisation stage. The structured needs from different groups were rewritten into clear evaluation statements. This makes it easier for the public to rate and score them. The questionnaire survey was conducted through a combination of online distribution and on-site QR code invitations at Hanzheng Street (see
Supplementary File S1 for the detailed questionnaire). After excluding questionnaires with incomplete responses, obvious duplication, or abnormal scoring patterns, a total of 140 valid samples were ultimately obtained.
The internal consistency of the questionnaire was tested, and the Cronbach’s α coefficient was 0.946. The scale shows good reliability. The respondents’ familiarity with Hanzheng Street showed an even distribution (
Figure 9). The survey participants came from two groups: people who know Hanzheng Street well and some people from outside the area. People from different groups took part in this research. Doing so stops the results from leaning only toward keeping old memories. So it avoided overlooking Hanzheng Street’s future potential and its appeal to people who are new to it.
The public’s overall evaluation of the 17 renewal scenarios was at a high level (
Figure 10). Survey results show that the updated scenario improved clearly in every aspect. Average scores for the five parts were from 4.10 to 4.27. Also, the average score for the updated designs was 4.19. About 82.8% of the people gave a score of 4 or 5, showing that most people like the new plan for Hanzheng Street (
Figure 11). In the ratings for different renewal plans, clear paths and order got the highest scores. But local character and business appeal got lower scores. The scores for business appeal were very different in each plan. This means the public is very sensitive to the business vibe. Most of the lowest scores were in road-related scenarios. Properly defining road usage during renovation is therefore essential to prevent the streets from becoming overloaded with extra functions.
The highest ratings were most frequently observed in Q10 (
Figure 12), which represents an edge scenario where land and water meet. Evidently, the river scenery is a vital element of Hanzheng Street, meaning that proper renovation can significantly increase its attractiveness. Lowest ratings were mostly for the Q2 residential access roads (
Figure 13). It means the public is still not satisfied with the updates to these narrow streets. At the same time, daily travel and the quality of life for Hanzheng Street residents need to be made better. When updating, the main job of each road needs to be decided first. The plan should focus on this main use and limit other extra uses.
Compared with traditional methods, the framework proposed in this research demonstrates methodological differences across three stages (
Table 9). The main difference is that this research incorporates public experience throughout the early-stage renewal process, forming a continuous and efficient participatory method.