Objective Promoting the construction of all-age-friendly cities is an important measure to practice high-quality development. Citizens can engage in long-term, numerous and diverse outdoor activities in urban comprehensive parks. Promoting all-age friendliness of urban comprehensive parks is an important aspect of effectively implementing the construction of all-age-friendly cities. The construction of all-age-friendly urban comprehensive parks can provide all-age people with open spaces which have comfortable and vibrant environments, and can also create intergenerational activities and promote the physical and mental health of all people. At present, the degree of all-age friendliness of urban comprehensive parks is relatively low. There still exist problems such as unbalanced distribution of activity quantity, activity type, and activity space among different age groups, as well as significant differences in activity quality. The purpose of this research is to provide a scientific basis for the construction of all-age-friendly urban comprehensive parks by exploring the evaluation method for all-age friendliness of urban comprehensive parks.

Methods This research constructs a quantitative evaluation method for the all-age friendliness of comprehensive parks from the two dimensions of crowd activity and physical space. First of all, the evaluation model and method for all-age friendliness of crowd activities in comprehensive parks based on activity characterization are constructed. Next, the evaluation indicator system and method for all-age friendliness of physical space based on the relationship between the needs of all-age people and the elements of park planning and design are constructed. The evaluation system for all-age friendliness of crowd activities and that for all-age friendliness of physical space complement each other. As a result, a relatively complete evaluation method for all-age friendliness of comprehensive parks is constructed.

Results At the level of crowd activities, this research constructs the evaluation indicators and measurement methods. This research takes four representative comprehensive parks in Xiamen as examples for empirical research. Based on the evaluation of crowd activities in the four parks, it is found that there are differences in the all-age friendliness of different types of comprehensive parks: 1) Haiwan Park has the highest degree of all-age friendliness, but its elderly friendliness is relatively poor; 2) Zhongshan Park in the old urban area attracts more citizens, is more inclusive towards the elderly and children, and has a relatively high degree of all-age friendliness; 3) Nanhu Park has a relatively high degree of all-age friendliness, but the proportion of its activity types is imbalanced; 4) the complex terrain of Jinbang Park in mountainous areas limits the setting of activity venues, resulting in the lowest degree of all-age friendliness, manifested by the low degree of friendliness of age structure and activity space distribution of the activity crowd. In addition, there are also significant differences in activity friendliness among different age groups in the parks: 1) The parks have the highest degree of activity friendliness to the elderly group with the proportion of elderly people closest to the ideal value, the highest degree of friendliness of spatial distribution, and relatively high degree of friendliness of activity type and activity quality; 2) the parks have a relatively high degree of activity friendliness to the children group, which is marked by higher degree of friendliness of activity type and activity quality, but there is a large variation in other indicators among different parks; 3) the parks have a relatively low degree of activity friendliness to the middle-aged group, because there is a large difference between the proportion of the actual number and that of the ideal number of middle-aged people, and the degree of friendliness of activity space distribution and activity quality are both relatively low; 4) the parks have the lowest degree of activity friendliness to the youth group, as all indicators except for the activity type are at a relatively low level.

Conclusion The research results on all-age friendliness of crowd activity and that of physical space are basically consistent. The indicators regarding crowd activity and those regarding physical space complement, couple with, and verify each other. The synergy of the two can effectively evaluate the all-age friendliness of comprehensive parks. This method provides a new approach for evaluating the all-age friendliness of urban public spaces and provides a scientific basis for the planning, construction, and management of urban comprehensive parks. The all-age friendliness evaluation of urban comprehensive parks should not only focus on external indicators such as the number, type and area of activities for different age groups, but also comprehensively consider internal indicators such as activity quality. It is suggested to optimize the planning of urban comprehensive parks in terms of functional layout, access system, spatial site, diverse land sense and evaluation mechanism in the future, apply the evaluation indicator system for all-age friendliness to implement the evaluation of planning and design schemes, built environment, etc., and coordinate innovative implementation mechanisms for urban renewal, quality improvement actions and other projects to effectively promote the construction of all-age-friendly parks and achieve high-quality urban development.