Improving the sense of citizens’ happiness in cold regions during the COVID-19 pandemic blockade through plant color planning — Taking the Harbin Institute of Technology Community as an example.

Harbin is one of the earliest China's cities that conducted color planning. Due to the influence of the cold geographical environment and the culture of immigrants, the urban color has become a cultural phenomenon deeply rooted in the hearts of the local people. Harbin, as one of the most famous gateway cities in China's "One Belt One Road" project, its position in Asia is becoming more and more important. Compared with international metropolises with excellent color planning such as Turin and Paris, Harbin has the potential to develop into a similar city, thererfore research on color planning in Harbin requires greater attention. In particular, Harbin was the center of the pandemic in the first half of 2020 in China. During the lockdown phase of the COVID-19, Plant color landscape was the most common view outside the community window. People had a deeper understanding of the creation of its color atmosphere. In addition, for most of the communities in cold regions such as the Harbin Institute of Technology (HIT) Community, the optimization of the color landscape is essential to improve the sense of the indoor happiness of the residents in the university (especially during the lockdown period due to the pandemic). Although plants are an important part of the sustainable color creation of the community environment, the current researches mostly start from architectural colors and less on plant colors. This article takes the plant landscape in the entrance area of HIT Community as the research object, draws on the perspective of resources dual-evaluation, and comprehensively evaluates the feasibility and necessity of the Community's plant color planning from the perspective of the supply and demand of Community plant colors. On the plant color supply side: select colorful flora that is well adapted to the climate environment of Harbin, use the AHP method to comprehensively evaluate its aesthetics, ecology, impact on residents’ feelings and culture. The color plant clusters with higher scores are selected as the plant resources for color planning. On the demand-side: through the investigation of the plants’ color in the entrance area of the college, it is found that the current campus plant color creation still has the following problems: 1.There is no comprehensive consideration mechanism for the color characteristics of campus community plants; 2. The color plant varieties are less used, the color is relatively single, the style is dark, and the color system is not rich enough; 3. The color landscape management is extensive, the overall effect is not satisfactory, 4. The planting of plants has less consideration for the health and emotional well-being of residents, and there is an urgent need for plant color planning. In the end, this article combines the campus landscape improvement project of HIT Community. Innovatively, use the subject control method to optimize the plant color landscape, improve the recovery effect of plant color landscape on the well-being of the residents in cold regions. It verified the feasibility of plant color planning in cold region communities, and provide practical reference and theoretical support for subsequent research.