Crowdmapping informal urban infrastructure to improve waste management

Map showing Geo-tagged survey responses, heat maps and trash maps overlaid on Open Street map/satellite images of Zanzibar islands.

Project Background

In Zanzibar, the high per capita generation of solid waste, along with the inappropriate disposal of the waste products, is a problem across all sectors of Zanzibar’s economy. It is estimated that about 60% of all solid waste produced in Zanzibar is not properly collected and sorted, leading to the accumulation of untreated and potentially toxic substances at unauthorized landfills and dumpsites (RGoZ, 2013). In this regard, tourism-oriented establishments, such as hotels and restaurants, contribute disproportionately to waste production, representing roughly 80% of all waste generated in Zanzibar (The Citizen, 2018).

Given the high resource requirements of the tourism sector and the rapid turnover of guests, hotels consume many disposable appliances, such as plastic bottles, food and kitchen materials, tissue paper and laundry products. Without sustainable practices, the resulting rubbish and sewage produced could harm both the terrestrial and marine ecosystems.

In this experiment, the team explored the possibility of a mechanism to attract bankable investments in recycling technologies in order to increase the efficiency of the solid waste management system in the region – An effort towards a circular economy that also contributing to the blue economy initiative. Recently the UNDP Accelerator lab, the state University of Zanzibar, Open Map Development organisation together with UNICEF conducted a virtual sense-making exercise to understand the context of solid waste ecosystems in Zanzibar including looking at the presence of solid waste management systems such as recycling plants, solid waste collectors and landfills, and the leadership around it. Its partners, OpenMap Development Tanzania and SUZA had participated in a similar initiative funded by the World Bank.

In this phase, the team intended to embark on testing the application of the collective intelligence approach to address the principal problem in solid waste management which is the ‘data gap’ using GIS tools. These unusual data sources can quickly gather information on hotspots, identify the required number of collection points and their locations, suggest waste recycling & sorting points, the volume of waste generated per source type, the number and types of potential clients, and waste composition and validate the current dumping site location.

The initiative will include an in-depth review of the existing datasets on solid waste management to explore ways of complimenting the previous project in achieving a desired collaborative impact. MSM management is not a one-man show, it requires a multidisciplinary approach from a range of stakeholders including developers, innovators, data scientists, community experts, etc.

Data Collection Methodology

The methodology entailed the following:

  • Developed quantitative questionnaire that assess the extent of improper waste management and uploaded them in the ODK (Open Data Kit) app platform
  • Upload questionnaire on Open Data Kit platform App
  • Install ODK app in data collectors’ phone (android/iPhone)
  • Tested/piloted the App
  • Data collection
  • Data analysis, Interpretation and visualization


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