研究論文

Roof-top Gardening (RTG) in Capital Cities of Nepal and Japan
Building Resilience to Climate Change
Tuladhar, Astha

Visiting Researcher, the Sacred Heart Institute for Sustainable Futures

Bushell, Brenda

Former faculty member, the Sacred Heart Institute for Sustainable Futuresprioritized in Kathmandu also due to the risk from seismic
Background

activity (Gautam et al., 2017) which can serve as space fordisaster relief. Free open spaces have become so scarce inBy 2050, the UN forecasts the world population to reach

Kathmandu that even river bank encroachment poses a new

9.7 billion; 68% of that population is expected to live in cit-problem (Tamrakar & Parajuli, 2019). Supplying food to Kath-ies and the fastest urbanization is expected to occur in low or

mandu is often obstructed by natural calamities like floods

middle-income countries. To make our future cities sustain-and landslides that damage road connectivity, resulting inable, there is an urgent need to develop strategies targeted tosudden rises in food prices.

withstand the effects of climate change, environmental deg-

On the other hand, Tokyo, the capital city of Japanradation, and high energy demand. Such inter-related prob-

since 1868, is known as one of the most densely populat-lems resulting from rapid urbanization can be addressed by

ed cities of the world, and spreads across an area of 2,191

diversifying land-use in urban areas for better productivity.

square kilometers. Tokyo has public parks in 82 locations

In this report, we focused on rooftop space which is often

totaling 2,030 hectares which also serve as disaster refuge

under-utilized but has much potential to boost productivity.

sites, the significance of which was recognized since theBy selecting the capital cities of Nepal and Japan we aim

Great Kanto Earthquake of Tokyo in 1923 and as Masuda

to compare the context and conditions in a developing and(2014) mentioned, landscape architecture plays an importanta developed country. This comparative approach, is usefulrole in disaster-prevention, response and social resiliency.

to gain new perspectives on building resilience to climate

In the report by Tran & Murata (2019, 2020), green infra-change and can be applied further in other developed or de-structure like rooftop gardens in Tokyo, are associated withveloping countries.

usage, space affordance as well as image of identity. Kimura

Kathmandu, the capital city of Nepal with 32 wards,et al., (2004) cautions that cultural and social aspects mayspreads across an area of 49.45 km². It is one of the fastest

discourage rooftop gardening in Tokyo as membership tourbanizing cities in Asia. Nepal was among the ten countries

gardening clubs is often required due to difficulty in access-most affected by extreme weather events over the 2000–

ing roof space. According to the world population review,2019 period according to the Global Climate Risk Index

Tokyo’s population decreased to almost 14 million in 2021

(Eckstein et al., 2021). World population review reported thatand the aging of population signals the need for local social

Kathmandu’s population reached 1,521,000 in 2022 which

engagements like gardening.

is an increase of 3.33% from 2021. Built-up areas in Kath-By comparing the varying lifestyles, resource availabil-mandu Valley are expected to increase further to 352 km² byity, cultural aspects and other contrasting urban contexts of2050, effectively doubling the equivalent 2018 figure (Mestathese two cities, we can gain further insight to build futureet al., 2022) which means drastic loss of farmlands and urban

cities resilient to climate change and natural hazards.

greenery. Creation of public parks and open space must be50

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Sustainable Futures Vol.2 2022

Differences, similarities and future directions for RTGs inof beer gardens is a seasonal thing. Such beer gardens on

Kathmandu and Tokyo

roof areas are either temporary or permanent set-ups sometimes adorned only with fake plants if any. To save the cost

1. Building architecture: In Kathmandu, RTGs exist onof maintenance, renting decorative container plants for fixedprivately owned residential homes, whereas, in Tokyo,

time periods can become new start-up businesses in both cit-

they exist mostly on public buildings like mansions, officeies.

buildings etc. Privately owned homes in Tokyo usually haveslanted tiled roofs, not terrace-style roofs like in Kathman-

4. Easing access to gardening space: In Kathmandu, roof-

du where private gardening is possible. Changes in buildingtop gardens on private homes are maintained by home-own-architecture can provide more roof space in both private anders themselves or in some cases hired gardeners. Residents

public building structures in these cities.

who rent rooms located on the lower floors of these homes
usually have no access to roof space for gardening purposes

2. Roof space utilization: In Kathmandu, the basic purpose(Tuladhar, 2019). In Tokyo, residential mansions keep theirof RTGs is diverse. Roof space is used for growing edible androofs locked for security reasons. Home ownership is expen-

ornamental plants, recycling organic kitchen waste, harvest-

sive in cities, so private rooftop gardening is not so com-

ing rainwater, placing water supply poly-tanks, solar water

mon in Tokyo where rooftop gardens on public buildings

heaters and solar panels to generate electricity. In Tokyo,

are maintained by hired professional horticultural service

slanted roofs of private homes are used to place solar pan-providers. In general, growing edible vegetation on private

els to generate electricity for sale and home consumption.

property is somewhat of a luxury in cities, however the num-

Edible plants are uncommon on roofs in Tokyo, however,ber of RTGs is growing in Kathmandu. Reasons vary, but theexceptions like the “garlic chive (Allium tuberosum) house”

majority of gardeners want to avoid buying vegetables withbuilt by Terunobu Fujimori, a Japanese architect and archi-pesticides, save on their grocery bills, and most importantly,

tectural historian (Seo, 2019) in Kanagawa prefecture gained

be self-sustainable and not be affected by food shortages andmuch attention. The Ginza Bee Project is another example

inflation. Gardening facilities for the general public must be-of harvesting honey from bee boxes placed on rooftops.

come the next public asset like public libraries that are run

Otherwise, Tokyo’s public buildings are used for car park-on government tax in both cities. Incorporating such garden-

ing or have park-like gardens created for recreational pur-ing facilities in the town-planning strategies would benefit

poses rather than growing edible vegetation. The greenery

populated cities, and could be encouraged by tax deduction

on roofs reduces the heat island effect and saves energy on

for greenery creators, individuals or enterprises.

air conditioners (Bass & Baskaran, 2003). To further increase
and utilize roof space, building design and materials used for

5. Facilitating the trend of RTGs: In Kathmandu, formally

rooftop gardens must be reconsidered for heat absorption inregistered paid membership-based gardening clubs specifi-

both cities, thus categorizing rooftop gardens according tocally for rooftop gardening do not exist yet, however freeobjectives, be it commercial, social, educational, therapeutic

online social media groups dedicated to rooftop gardeningor ecological, as mentioned by Nasr et al.（2017）.

have become popular platforms for gardener-to-gardener interaction, problem-solving and learning. In Tokyo, free plat-

3. Economical, ecological and educative: In Kathmandu,

forms providing advice on gardening are rare, often due torestaurants on rooftops have become an example of commer-

the concept that social media is unsafe, risky or because its

cializing the roof space and increasing its real estate value.

aging population are not driven to the internet. Internet-lit-

By extending their seating capacity on rooftops, restaurants

eracy and smart phone ownership alone, can inspire amateur

grow ornamental plants to attract customers as well as polli-gardeners in core cities, and residents in Kathmandu seem tonators like birds and bees which enhances the biotope effectbenefit largely by the use of internet. Kathmandu residents

as well. If the names and features of plants are displayed

often organize and join trainings and educational programs(like in a botanical garden), the experience can becomeon RTGs backed by the metropolitan office or non-govern-

educational, too. In Kathmandu, plant names displayed inmental organizations without having to pay an expensive

local languages would gain much public interest because ofmembership fee or participate in obligatory meetings. They

its linguistically diverse population. In Tokyo, popularity

are often introducing new growing methods by posting vid-51

Roof-top Gardening (RTG) in Capital cities of Nepal and Japan : Building Resilience to Climate Change

eos online. In Tokyo, gardening clubs, societies and organi-in green infrastructure building that best fit the city residents’zations run on membership fees and individuals who afford

life-style and culture and how it can help them withstand thethe time and membership join for social interaction rathereffects of climate change.

than for hands-on gardening experience or skill.
Acknowledgment: We would like to extend our gratitude
6. Need-based green infrastructure: In Tokyo, stable foodto Dr. Sunil Babu Shrestha, the vice-chancellor of NAST

supply chain, convenient online food delivery systems, busy

(Nepal Academy of Science and Technology), Dr. Ohayake

and long working hours and most importantly living away

Yui Assistant Professor at the Faculty of Engineering andfrom family members in one-room apartments, detaches

Design, Kagawa University and Ms. Gauri Jayswal, MSc.

residents from the natural experience of growing food andstudent at the Central Department of Environmental Science,

connecting with nature. The yearning for greenery is proven

Tribhuvan University, Nepal for their valuable contribution

by the usage of verandas and walls as Tokyo residents growfor this paper.

“green curtains” (Braiterman, 2011) on verandas by growing
climbers like ivy, morning glories or vegetables of the cucurbitaceae family like cucumbers, bitter gourds and etc.
Known as the “breathing walls” (Koyama et al., 2015) indoor

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Conclusion
In a world where cities are branding themselves basedon the level and quality of their green spaces, preservationof a city’s unique characteristics of biodiversity and local
identity remains the key point, whether it be Kathmandu orTokyo. In our globalized world today, it has become mucheasier to share and learn from each other and notice how
wonderfully human civilizations of the past developed
unique ways to tackle common problems. At a time whenclimate change affects us all in varying degrees, the key tosustainability lies in understanding that, to solve commonproblems, simply applying the same solution methods, may
or may not work to the same extent every time. Every city
is unique in its history, culture and its residents’ life-styles.
Rooftop gardens and other green infrastructures can bringnew changes to urban life-style and cityscape and vice-versa. By comparing the context of developing and developed
countries, we could list many unexplored ideas and possibilities in both cities. Further studies are required to find details52グローバル共生

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