The described situation was an opportunity for the nature based solutions (green wall creation) implementation. Particularly, based on the scientific data available from more than 160 Yerevan kindergartens specific one was identified and selected ensuring the maximum benefits for the kindergarten territory, its sounding and children’s health. The testing site - kindergarten was built in former Soviet Union period and did not underwent any reconstruction action. Due to its spatial location the kindergarten is experiencing a significant impact from the heavy traffic from street site and the its territory is open for the migration and accumulation of pollutants into the playground soil layer. The study showed that selected kindergarten soils are highly polluted (https://doi.org/10.1016/j.ecoenv.2017.04.013) and toxic elements pose a risk to children health. Therefore, it is a major challenge to reduce pollution level and prevent further penetration of pollutants into the N143 kindergarten territory regarding, which a nature-based solution was applied. The implementation of nature-based solution on the territory of Yerevan has more than 10 years of history. Particularly, according to the Yerevan Municipality request The Center for Ecological-Noosphere Studies (CENS, http://cens.am/) developed a “Target tree planting program” which was a unique and scientifically justified strategy for environmental pollution mitigation and prevention. The implementation of Yerevan’s “Target tree planting program” is still in the process. The creation of a green wall in the sounding of N143 kindergarten is a showcase of the way a particular nature-based solution could be implemented: the creation of a green wall, which took a short time and needed a very limited, care may than keep its function during years without any extra-costs. It is also an excellent example for the other kindergartens, schools and sport complexes where such kind of nature-based solution can be easily implemented. Potential impacts/benefits: The green wall in the sounding of N143 kindergarten may ensure sustainable environmental conditions including better air quality in the kindergarten territory. The care of the plant species (Virginia creeper (parthenocissus quiquefolia), Amur grape (vitis amurensis), monkshood vine (ampelopsis aconitifolia)) used for the green wall creation may serve as an excellent platform to teach kindergarten children to love and preserve the environment. The creation of green wall brings together the representatives of local Authorities (Municipality), scientists, NGOs and kindergarten staff and supported to increase the level of local environmental quality and public awareness of nature, to provide aesthetic and health benefits.

• Improve air quality
• Increase accessibility to green open spaces
• Increase amount of green open spaces for residents
• Increase awareness of NBS solution & their effectiveness and co benefits
• Increase population & infrastructures protected by NBS
• Increase social interaction
• Increase well-being
• Provision of health benefits
• Reducing wind speed

The main success factors of nature-based solution implementation were:

• availability of scientific data on the kindergartens areas,
• effective collaboration of local authorities, scientists and kindergarten staff,
• availability of funds
• time to search for additional funding for other problematic kindergartens and/or territories,
• availability to monitor kindergarten’s territory to reveal the extent of green wall pollution prevention capacity.

The main limiting factors were:

• the time it takes for the Municipality to sign cooperation agreement,
• the lack of financial support from Municipality site,
• lack of funds, which limited the implementation of nature-based solution only in one kindergarten.

https://oppla.eu/casestudy/18930