Community Mapping Urban Risks in Mwanza

In late 2020 and early 2021, Spatial Collective (SC) carried out the Community Mapping of Urban Risks in Mwanza under the broad framework of the Tanzania Urban Resilience Program (TURP). To complete the project, the company partnered with the Humanitarian OpenStreetMap Team (HOT) and OpenMap Development Tanzania (OMDTZ). This assignment intended to showcase how locally accessible, low-cost technologies can support resilience building and urban development planning through the production of high-quality spatial information. Specifically, the assignment’s goal was to train university students and government authorities in community mapping by coordinating several community mapping engagements in pre-selected wards in Mwanza and producing up-to-date, open, and accurate data on exposure to floods and rockfalls.

Seventy-nine students from the Institute of Rural Development Planning (IRDP) and the Saint Augustine University of Tanzania (SAUT) participated in a two-month-long industrial training program. During this period, they learned about the theoretical and practical aspects of community mapping. By putting theory to practice, they, together with hundreds of community members, collected a series of disaster-related data touching on flood-prone areas, historical rockfall incidents, urban exposure, and drainage infrastructure. The work focused on two municipalities: Nyamagana and Ilemela.

Students participating in the training

Using a mixed-method approach which consisted of digitizing the satellite imagery, mobile and GPS field data collection, community consultations, and stakeholder meetings, the students collected more than 300,000 buildings using satellite imagery, 15,000 locations of flood-prone areas, 800 locations exposed to rockfalls, and more than 80,000 points on urban exposure. In addition, more than 1,500 drain segments with 177 km of drainage lines, 3,113 drainage-related points, and 1,328 elevation points were mapped using a combination of mobile phones and Do It Yourself Real-Time Kinematic (DIY RTK) GPS.

A sample of the data collected

After several months of fieldwork, the students gained fundamental knowledge in setting up community mapping projects and producing datasets that benefit Mwanza’s local authorities and other stakeholders in infrastructure improvement projects. Finally, the project highlighted the potential of pairing innovative technologies with local capacity to provide stakeholders with timely and accurate information.