Rooftop agriculture on the roof of the world

When the Covid-19 pandemic disrupted food supply, Bijaya Manandhar, did not anticipate that her life would be ruined upside down.

Her hometown of Banepa has seen the city expand rapidly, obliterating much of the surrounding fertile plains. So the 52-year-old just went back to her ancestral livelihood — not on terrace farms, but on her rooftop terrace.

“The food on my plate now comes from my roof,” says Manandhar proudly. “We had to regain our food self-sufficiency during the pandemic so we had no other option but to grow vegetables in our roof garden.”

Manandhar is part of an initiative Kausi Kheti and Karesabari Kranti (Rooftop Farming and Gardening Revolution) which has an online membership of 52,000.

More than half the world’s population now lives in urban areas, and 80% of all food produced globally is consumed in cities. In future, the socio-economic and environmental sustainability of food systems will largely be determined by the diet of urban and peri-urban inhabitants. 

In Nepal, the urban population has spiked dramatically from 3.6% in 1991 to 6.5% in 2001, and is now 21%. Most of the migration took place during the conflict, and later families moved to urban areas for jobs. Kathmandu Valley, with an estimated population of 2.54 million, is growing at 6.5% per year, as one of the fastest-growing metropolitan areas in South Asia.

A survey in August 2020 found that one in every five households in Nepal during the pandemic did not have enough food to meet daily calorie requirements. 

Manandhar remembers as a child helping her family during the seasonal farming cycle, planting, weeding, harvesting. But there are now tall houses where her family farm once was. 

“The land is no longer for planting crops now, they now plant buildings there,” she says, gesturing at the houses from her rooftop.

Once known for its succulent vegetables that supplied the market in Kathmandu, Banepa is now the site for a research project by the Geomatics Engineering Society of the nearby Kathmandu University to study the scope for rooftop farming in the municipality. 

The study mapped roof spaces suitable for farming using OpenStreetMap to create geospatial data. This was a pioneering study, and could be upscaled nationwide if successful.

“Our research not only tries to shed light on the trends and benefits of rooftop farming, but creates a baseline survey, database and information to be used in the future,” explains Rehana Shrestha, Doctoral Researcher at Universität Bremen and adviser to the urban rooftop farming project in Banepa.

While the idea of rooftop farming is quite common and widely practised, the data regarding buildings, houses, and people practicing it in any peri-urban areas were thus far unavailable. That is why the open source OpenStreetMap (OSM) came in handy, as a platform to identify buildings with suitable roofs. The researchers still needed high-resolution imagery to map out Banepa’s buildings and roofs in detail. 

“We initially identified buildings, studied their types and shapes,” says Sushma Ghimire, a geospatial analyst. “Then we identified flat roofs and their types and created a database of the six wards in the municipality. Using OpenStreetMap, we have digitised every building footprint.” 

The research and database in Banepa could serve as a way forward in urban agricultural planning and policy-making that newly-elected local governments could implement. Locals like Bijaya Manandhar are on the frontlines of this research, since it is her expertise in farming that will make or break the experiment.  

The project has the full support of Banepa’s newly-elected municipal officials, who have allocated a budget line for urban farming. Deputy Mayor Bimala Sapkota says: “To help rooftop farmers we will also distribute compost bins to turn kitchen waste into fertiliser and also train them in rainwater harvesting techniques.”

The OSM and geospatial data have also helped identify areas with water shortage by presenting a detailed overview of roofs and water tanks available in houses spread across different wards: for instance, the maps have shown an absence of rooftop tanks in Ward 7, indicating water scarcity. 

At Kanthu Tole, farmers use plastic bags, pots and styrofoam as containers to grow food on, and Narayan Thapa of the Geometrics Engineering Society says farmers can also experiment with vertical farming to increase the area under cultivation. 

Researcher Rehana Shrestha is confident that the project will infuse a new passion for rooftop farming, especially among younger members of households.

“Projects like this provide opportunities for the empowerment of youth, cultivating a generation of young leaders, to create resilient communities,” she says. “And with climate-induced disasters, urban farming is more necessary than ever.” 

Read more: Four years later, Nepal’s farmers rise from the rubble, Lisa Choegyal