Using satellite imagery to enhance data in solid waste management

August 3, 2020

A pile of waste in a landfill at Buhongwa ward in Mwanza city. Photo by UNDP Tanzania

Elon Musk — 'The first step is to establish that something is possible then probability will occur'

When you hear the word ‘satellite’,what comes into your mind? moon landing? Star Wars? Curiosity or Apollo missions?-of course these words have almost become synonymous with space and its technologies and most definitely with satellite as a Geographic Information Systems technology which has  become an essential tool for monitoring long and short term land use practices as a result of human activities on the Earth’s surface. Indeed, not so common in our slice of the world but we are undoubtedly observing an upsurge of its usage to address various 21st century fast-paced developmental challenges such as climate change and its effects.

Perhaps you are also asking yourself, how then is this related to solid waste? Well, in  this  blog - a sequel to our  previous work on Design Thinking, we explored how the City of Mwanza in Tanzania intended to use new sources of data to inform its solid waste management operations-  that allowed the Accelerator Lab in Tanzania to think of  setting  the stage for experimentation on using innumerable and novel  4.0 related technologies such as satellite imagery. The idea behind was to find out on how the technology can enable actors in the solid waste value chain to utilize these novel sources of data that have probably never been used before to improve solid waste management. Ultimately, through a partnership model the lab programme aims at testing and scaling these innovative solutions to influence development programming, government policy or spinoffs into independent ventures.

The problem

A recent report by the world bank estimates that  cities around the world  generated as high as 2.01 Bilion tones a year, this was equivalent to 0.74kg kgs per person per day.  Due to high rates of solid waste generation, an annual increase of 70% to 3.40bilion tones in 2050 is expected.  In sub-Saharan Africa, it is estimated that over 90% of produced waste is often disposed on unregulated dumps or openly burnt. Improper waste management can lead to stern health and environmental hazards. When waste is not properly managed it contributes to global climate change through methane generation, serves a breeding ground for vectors and can even promote urban violence. As elucidated in our recent blog on design thinking, the city of Mwanza ( Where this project is undertaken) produced around 350tonnes of waste a day (almost 70% is organic), there is less investment in circularity and use of technology in the system. To conduct this experiment, we selected Buhongwa ward- a semi urban, peripheral location with high rural-urban migration rate, furthermore, the ward has a rough population of thirty thousand inhabitants and hosts the largest vegetable market in the region. Solid waste management structure in this ward is relatively informal with less or no investment in refuse collection or recycling. The ward also houses the largest sanitary landfill in the region, waste re-use and scavenging activities are evident.

How did we approach the assignment?

The UNDP accelerator lab partnered with Open Map Development Tanzania- a  non-profit based in Tanzania that uses various GIS technologies to create innovative solutions for various developmental challenges, furthermore, we  engaged  volunteer students  from Ardhi University. The students’ role in the assignment was to conduct virtual digitization (mapathon)- an approach used  due to travel restrictions as a result of COVID 19 pandemic eruption.

The following steps were undertaken; 1) creation of  a task on the open street map platform to divide the pilot area into several squares for mapping 2)open imagery sources such as Bing and Maxar were used 3)mapped images were reviewed and validated by a GIS expert 4)data was finally uploaded on the OpenStreetMap platform.

Digitisation of roads, waterways, ward boundaries and possible trash sites. Photo by OpenStreetMap

As a result of this virtual exercise the team was able to map 26,255 buildings, roads, waterways, and possible trash sites were identified as seen on figure 2 above. All maps can be seen accessed for free on the Open Street Map platform. This information will be complemented by a physical validation of all mapped structures and a mini survey to understand the community practices related to solid waste management in the ward. Indeed, the exercise produced a new set of data that never existed before; as the city’s head of Environment and Sanitation Department puts it;

‘we were not aware that this ward has so many buildings, we usually relied on large scale surveys which are protracted and expensive, this information will also be useful to our revenue collection department’ - Mr. D. Kamenya,2020


Post-mapathon outlook of the area as it appears on OpenStreetMap Platform

Next steps

Towards completion of this assignment the team will embark on, rapid validation of buildings, waterways and trash sites identified. Technically, the team will conduct a mini survey by using ODK collect app to understand;1) the community perceptions towards waste management and 2) conduct trash mapping.

It is anticipated that towards the end of this phase we will produce; 1) heat maps which shows the extent of illegal dumping  2) produce waste route wasting analysis report – a narrative which will allow aggregators to efficiently plan waste collection points positioning and 3) develop  an interactive map on OSM platform which will allow  crowdsourcing of further geospatial information related to the ward.

Looking on a bigger picture, outputs of this assignment will complement efforts by Tanzania country office to; 1) strategical support the city of Mwanza in attracting long and short term investments in its diverse resource endowments- and most importantly in this case pulling investors in circularity business and 2) to enable the city council to scale out the project to other wards for the purposes of improving its service delivery and potentially reach its goal of becoming a smart city in the near future and finally a virtual webinar will be organized to share results with a wider innovation ecosystem audience.

Drawing inspiration from Elon’s quote above, use of satellite imagery is quite a new phenomenon across most of the sub-Saharan countries, however we are optimistic that by presenting use cases such as this will enable municipalities, waste management companies ( aggregators), policy makers, statisticians and development experts in general  to find value on presented information and ultimately utilize it on a wider scale. We will wait to see that ‘probability’ emerge or perhaps we are seeing it already?

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For more information about UNDP Accelerator LabProgramme visit: 

By Peter Nyanda, Team Lead and Head of Exploration and Ghati Horombe, Head of Solutions Mapping, UNDP accelerator Lab, Tanzania