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Community mapping for flood resilience

Local community members living in slums create highly accurate maps of the most flood-prone areas of the city by using OpenStreatMap.

Photo of Jonston Weston
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Community mapping for flood resilience is the GIS based system where by local community members living in slums create highly accurate maps of the most flood-prone areas of the city using OpenStreetMap. It is a web system to create a free and open map of the entire world, built entirely by volunteers surveying with GPS, digitizing aerial imagery, and collecting and liberating existing public sources of geographic data. The system produces realistic natural hazard impact scenarios, maps and identifies areas which are mostly vulnerable to flood hazard, which will help for better planning, preparedness and response. The communities in slum are then trained to update the status of their environment even during disasters. The response team can use the information for better allocation of resources which will be needed during response phase. By so doing the level of impacts and disruption will be minimized and hence the level of resilience will be high. The Community mapping gives the opportunities to the community to map(participate) the infrastructures such as roads, drainage, sanitation and water supply by describing their status and identify their levels of vulnerability to hazard and hence being able to develop coping and strategies that will increase the level of resilience in their community.


The community members living in slums will be the first beneficiaries as they will be owning the system. Also the Government will use the data from OpenStreatMap provided by the community as the baseline information during preparedness and response plan. The government can use the data to plan for the resources that will help during disaster


The idea takes into account of urban slums and climate change because, the people living in slums are the most who are vulnerable to climate change induced disasters since such as floods, the settlement have insufficient infrastructures such as roads, sanitation, water supply, drainage and solid waste management. The climate change has attributed the flood occurrence in most of the cities but since these areas are more vulnerable they are hit harder. Therefore the idea provides for the sharing of information by using web based system and data is free and can be accessed by any one at any time. The information then can be used to improve the infrastructures and social services.


  • Yes, for one year or less


  • I’ve worked in a sector related to my idea for at least two years


  • Yes


I am working with Tanzania Youth Environmental Network(TAYEN) it is a Non Governmental Organization founded at the University of Dar es Salaam aiming at bringing Youth together to address issues related to environment including climate Change.


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Photo of Edward Anderson

Jonston - great idea to propose this and good to see that you are continuing to champion this through your networks of youth and university.

Comments: indeed is the ongoing evolution of the original proof of concept called 'ramani tandale' in 2011 in which Jonston was a star community mapper. It was after the devastating floods of Dec 2011 in Dar es Salaam that the community mapping began to really focus and develop a methodology for urban flood issues, but it is still not a well known project or methodology and its evolving all the time.

The challenge is a sequence of inter-connected issues: informal and unplanned settlements in watershed areas aggravate drainage, lack of waste collection services or poor drains maintenance also exacerbate the flood risk, and already poor communities are left with limited resources to deal with flood waters that are often contaminated with secondary hazards such as mosquito or water borne disease. The current ramani huria work is also supporting the local authorities effects to map and manage the current cholera outbreak.

In my view this idea is addressing several key challenges at once. First the mapping is producing critical local information on exposure in informal areas - both of vulnerable groups and on critical community infrastructure. Second, the mapping campaigns are working via interdisciplinary and heterogeneous groups of students, community members, red cross volunteers and local authorities - its building the ecosystem of stakeholders and capacities around the data. And finally, the participatory approach is also engaging local leaders in the conversations around risk management so that the process itself results in more than just a map.

Here is a video that was done for one of the local workshops:

Nice idea Jonston - hope that you can get support to scale up and mainstream this approach.

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