Heal the Earth via the heavens

Clay Technology magazine
15 Feb 2018

Khai Trung Le talks to Professor Stephen Luby about the use of satellite imagery to help change harmful brick manufacture in Bangladesh.

Many brick kilns in South Asia are not only a significant contributor to climate change but represent a health risk to operators and local communities. However, a collaboration led by Stanford University, USA, looks to combine satellite surveillance, bespoke algorithms and local engagement to help combat the impact of harmful brick production. 

Kilns in Bangladesh can output as much as 48,000kg of carbon monoxide in one season, with airborne particulates averaging more than 90 times World Health Organisation-recommended levels.

Stephen Luby, Professor of Medicine at Stanford University, told Clay Technology, ‘The primary approach is to identify infrared signatures using publicly available satellites.’ The project uses images from the Sentinel 1 satellite launched by the European Space Agency in 2015. Using these images and GPS locations of kilns found by ground teams, a model was developed by Stanford electrical engineering graduate student Abhilash Sunder Raj that can identify kilns from footage taken from space.

The model’s algorithm adjusts for seasonality – kilns do not operate in the rainy season between November and March – and false positives from fires and furnaces, based on parameters including size and surrounding areas. 

Even at this early stage, the model has been able to find kilns missed by ground teams. One outcome of the project will be a website where users can pinpoint kilns that violate ordinance on proximity to communities and design standards, as well as access information on how kiln owners can make their operations more efficient. Luby said, ‘It won’t just be an outdated report nobody sees.’

Flights of inspiration

Luby was first drawn to the idea of satellite coverage while flying 30,000 feet over India, observing brick kilns at ground level. He said, ‘If I can do this sitting in a plane, we must be able to detect kilns by remote satellite as well.’

He approached Howard Zebker, Stanford Professor of Electrical Engineering and Geophysics, for his experience developing space-borne radar systems and remote sensing data, and Dr Francis Fukuyama, Senior Fellow at the Stanford Freeman Spogli Institute for International Studies, for his expertise in governance issues and to help formulate a politically effective message. 

Other collaborators include clean energy research and advisory firm Greentech Knowledge Solutions, India, and the International Centre for Diarrheal Diseases Research, Bangladesh, which has supported the university’s research on the health impact of kilns for five years. 

Of how the project might improve local conditions, Luby said, ‘There is room for more policy improvement in Bangladesh. But like most weak states, the biggest gap in Bangladesh is not in the written policy but in implementation. We have engaged with the Bangladesh Rural Advancement Committee to assist in catalysing transformation in the sector.’ 

Three areas will be prioritised – the physical upgrade of kilns to improve efficiency and reduce pollution, developing an approach to mining clay that minimises the impact on agricultural productivity and supporting the livelihoods of brick kiln workers.

Professor Luby continued, ‘At scale, social impact investors could help overcome the capital constraints of traditional kiln owners. We convened partners in Bangladesh in January 2018, and have outlined an approach for going forward.’

Since first announcing the project in August 2017, the team has continued to refine the algorithm, as well as work with stakeholders in Bangladesh to map strategies to incentivise kiln upgrades. Luby said, ‘We anticipate that once we have the algorithm working in Bangladesh, it will be able to identify kilns across South Asia. Our vision is to transform brick manufacturing across the region.’