**2. Related work**

The system in the present study was developed by integrating plural systems such as Web-GIS, SNS as well as the registration system of walking information into a single system. Therefore, the present study is related to three study fields, namely, (A) studies regarding walkability, (B) studies regarding activity support system developed by GIS, and (C) studies regarding social media GIS.

In A studies regarding walkability, as this topic attracts attention just in recent years, there were few preceding studies until now. Cerin et al. [5] examined the factorial and criterion validity of the neighborhood environment walkability scale (NEWS) and developed an abbreviated version (NEWS-A). Kondo et al. [6] investigated the actual association between physical activity (PA) and neighborhood environments (NE) focused on either objectively measuring the NE or the residents' perception of NE in Japan. Inoue et al. [7] conducted a questionnaire survey to investigate the relationship between living environment and walking, just targeting Japanese.

In B studies regarding activity support system developed by GIS, Ishizuka et al. [8] proposed a similarity search method for the movement tracking data of tourists obtained from their location data and its text information. Kurata [9] developed an automatic generation system for sightseeing courses using Web-GIS and genetic algorithm (GA). Kawamura [10] proposed the use of standard tags related to sightseeing on SNS and set up a Website to organize tourism information of Hokkaido on the Internet. Sasaki et al. [11] gathered information concerning local resources and developed a system that supports the sightseeing activities of each user. Fujitsuka et al. [12] used the pattern mining method, which lists and extracts the time series action when touring sightseeing spots, and developed an outing plan recommendation system. Ueda et al. [13] generated post-activity information from the sightseeing activities of the users and developed a tourism support system, which shares such information as prior information for other users. Okuzono et al. [14] took into consideration the preferences of several people using photos, and proposed a system that recommends sightseeing spots.

Fujita et al. [15] developed a navigation system using augmented reality (AR), Web-GIS, and social media, in order to support sightseeing activities during normal occasions and evacuation in case of a disaster. Zhou et al. [16] develop a sightseeing spot recommendation system using AR, Web-GIS, and SNS. Based on these results, Mizutani et al. [17] developed a sightseeing spot recommendation system taking into account the change in circumstances of users. Abe et al. [18] developed a tourism information system with language-barrier-free interfaces, mainly targeting foreign visitors. Mizushima et al. [19] proposed a service data model in design support system for sightseeing tours, based on tourists' three types of requests (geographical, time, and meaning information). Yamamoto [20] developed sightseeing navigation system, using 2D and 3D digital maps of the Web-GIS, and just targeting foreign visitors.

In C studies regarding social media GIS, Yanagisawa et al. [21] as well as Nakahara et al. [22] developed an information sharing GIS, using Web-GIS, SNS, and Wiki, with the purpose of storing and sharing information of the local community. Yamada et al. [23] and Okuma et al. [24] developed a social media GIS, which strengthened the social media function of the information sharing GIS mentioned above. Based on such systems developed from preceding studies, Murakoshi et al. [25] and Yamamoto et al. [26] developed a social media GIS supporting the continuous use of disaster information during normal occasions and in case of a disaster. In addition, based on these social media GIS, Ikeda et al. [27] developed a social recommendation GIS to accumulate sightseeing spot information and recommend sightseeing spot according to the preference of each user.

Among the preceding studies in related fields as listed above, B and C support the tour planning and accumulating and sharing of spot information for activity support. Additionally, the existing system developed in B and C is not suitable to support walking. Against the abovementioned preceding studies, the present study demonstrates the originality to develop a walking support system, by integrating Web-GIS as a base system, an SNS, and a registration system of walking information, and targeting many generations. Furthermore, referring to Inoue et al. [7] in A, the present study shows the usefulness to provide important geospatial information from the viewpoint of walkability to users, and support them to select their suitable walking courses in response to their preferences, aptitudes, and situations.
