Resilience Scanner

Community-Based Open-Source Flood Risk Mapping Platform

Solution Overview

Ramani Huria, meaning "Open Map" in Swahili, is a community-based mapping initiative launched in 2015 to create comprehensive and accurate maps of Dar es Salaam, with particular focus on the most flood-prone areas.[6] This approach trains university students and local community members to create highly accurate maps of the city's most vulnerable neighborhoods using open-source tools.[2] The initiative addresses critical data gaps by enabling communities formerly "off the map" to generate vital, accurate, and timely risk information for decision-makers.[11]

Technical Components

The mapping initiative uses open-source tools including Open Data Kit (ODK) and Open Map Kit (OMK) for data collection, which are easy to learn and can be used by anyone with an Android smartphone.[4] For map production, the project employs QGIS and Java OpenStreetMap (JOSM), which are also open-source software.[4] The technology incorporates GPS-enabled mobile apps, drones, and unmanned aerial vehicles to capture aerial and street-level imagery.[9][11] GPS accuracy of devices used by community mappers is checked to ensure it is usually less than 4 meters.[8] Students collect critical data directly from community members using forms on smartphones (Open Data Kit) to precisely identify the extent of flooding within each city ward.[5] The initiative initially used OpenMapKit for data collection in Hananasif ward and part of Kigogo ward, then switched to Open Data Kit (ODK) because polygon format data is more difficult to analyze, especially when producing heat maps that require data collected as points.[8] Unmanned aerial vehicles or drones produce digital maps to assess flood-prone areas, take preventative measures to mitigate flooding impact before the rainy season, and identify appropriate upgrades to informal settlements.[10] The project trained local pilots and worked with regulatory authorities to obtain permits, developing and flying a locally made bamboo drone to capture images whenever needed.[15] Survey drones that cost a few thousand dollars can be deployed even when it's cloudy, replacing chartered flights that previously cost tens of thousands of dollars.[15][11]

Implementation Details

Since 2015, the project mapped 49 out of 90 wards in Dar es Salaam, equivalent to approximately 50% of the city, comprising about 450,000 buildings and 1,700 schools.[4] The initiative, funded by the World Bank and implemented by Humanitarian OpenStreetMap Team (HOT), managed to map three-quarters of one of Africa's megacities between 2015 and 2020.[15][7] The first phase, which began in 2015, trained more than 150 students to create detailed maps of the city.[15] A second phase started in 2017 to capture even more detailed and critical exposure and flood hazard information on the most at-risk neighborhoods, giving communities tools to build flood resilience themselves.[3][1] This second phase combined exposure data and flood hazard data to conduct risk analysis of potential future disasters.[1] Using aerial and street-level imagery, GPS-enabled mobile apps, and drones, the project mapped 29 wards (home to 1.3 million citizens) and 1,254 kilometers of waterways and 3,396 kilometers of roads.[9] Nearly 500 university students mapped a total of 228 sub-wards within 7 weeks to create a community asset and threat inventory, which is a collection of action maps, reports and open data for disaster management.[4] Students mapped an area covering a total of 35 wards, home to the majority of Dar es Salaam's population.[5] The initiative is a partnership between the World Bank, the Humanitarian OpenStreetMap Team (HOT), Ardhi University in Dar es Salaam, and the city's municipal authorities.[6] OpenMap Development Tanzania (OMDTZ) is the primary local organization with the team carrying out activities.[4] The project is supported by the UK Department for International Development (DFID) in partnership with Humanitarian OpenStreetMap Team, Tanzania Red Cross, Ardhi University, and the City of Dar es Salaam.[14] The initiative is implemented in the frame of the "Building Climate Resilience in Tanzania Water Sector" project funded by the ACP-EU NDRR Program.[2] Under a Memorandum of Understanding between GFDRR, the World Bank, the UK's aid-funded Urban Resilience Programme, and Tanzania's Ardhi University, the second phase trained about 300 Urban Planning and Geomatics students to capture community knowledge and help document the rapidly changing city more accurately.[5]

The project trained nearly 1,000 students and local leaders to teach their communities how to collect data and play a part in flood mitigation programs.[3] More than 1,000 students and 300 community members have been involved in the project.[15] Specifically, 470 university students were trained to work on data collection and map production via the asset and threats project, and more than 300 Red Cross members were involved in the mapping.[4] The training was conducted by fifteen student supervisors from Ardhi University, who prior to leading the training received three months of instruction with the initiative.[17] Under the guidance of consultants from the Humanitarian OpenStreetMap Team and ten other Tanzanian students from the project's pilot who became trainers, Ardhi students conducted the mapping work.[5] The three days of training for new students included an introduction to OpenStreetMap (a free editable map of the world) and mapping tools such as field papers and the GPS Unit (eTrex 30), used to record tracks and waypoints.[17] Training was given in JOSM software, an open-source offline editing tool of OpenStreetMap.[17] The training included use of the OSM Tracker (an open-source Android phone application available in the Google Play Store) which does the same work as the GPS Unit for data collection but has a more user-friendly interface.[17] Following the training session, the initiative successfully activated one hundred fifty new active OpenStreetMap users from two universities.[17] The training took the form of 43 sessions with varying target audiences that covered topics including Java OpenStreetMap, InaSAFE, QGIS, data quality and quantity, and general map creation.[13]

The team uses community mapping techniques to engage with local leaders and teach community inhabitants free, open-source data collection tools from their smartphones.[1] The community mapping process begins by introducing the team to ward officers, explaining the project and providing an introductory letter addressed to Subward officials, then being introduced to the Wajumbe local leaders who operate at the most granular level of administration system that exists in Dar es Salaam.[8] Ten cell leaders (Wajumbe) select a community member who owns a smartphone so that the phone can be installed with Open Data Kit (ODK) Collect and they can download the survey form from the server www.turkus.net, with the survey written in Swahili to avoid language barriers.[8] A community member conducting data collection is provided with scratch cards to buy internet packages and a power bank.[8] The trained students worked with communities living in informal settlements to carry out ground surveys to add different layers of data to the map - including drainage, infrastructure, and assets.[15] The mapping teams consist of students from Ardhi University and local community members, known as "mappers", with students bringing technical skills and enthusiasm while community members provide essential local knowledge and context.[6] By empowering students and local communities to do the mapping, the initiative was able to collect data at a much larger scale and at a much cheaper price than would have been possible with traditional surveyors.[15] Community members in 21 wards collaborated to deliver the same information at a fraction of the price, accounting for 1.3 million of the city's 5.5 million residents.[11]

The second phase focused on mapping the most flood-prone Wards such as Kigogo and Hananasif Wards to produce flood extent information which would later be used to inform decision making and flood mitigation plans.[8] Six wards were selected from seventeen flood-prone wards for community mapping, including Mabibo, Mburahati, Makurumla, Makumbusho Msasani and Keko.[17] In community surveys, respondents are asked questions such as "have you ever experienced flooding?", "how deep was the flood water?", "have you moved settlement because of flooding?", and "what do you think caused the flooding?".[8] The team creates a new dataset for each year flooding is reported so that flood impact can easily be visualized by year.[8] A community member who participated in the first phase stated that they used field papers and GPS devices to collect information which was time consuming and could result in data loss, but now with smartphones the data collection is quicker and less likely to lose data.[8] For the second phase – which began in 2017 – map data was collected with mobile phone applications, such as Open Data Kit and Open Map Kit.[15] Beyond drainage networks, students mapped health care services, toilets, water sources and various other elements of urban infrastructure to provide more information that can guide the Tanzanian government—from the local to national levels—in their efforts to improve flood resilience and service delivery across the city.[5]

Benefits and Impacts

The initiative enabled the collection of over 750,000 building footprints; 120 kilometers of imagery and surface models; 2,091 kilometers of roads; and tens of thousands of points of interest such as toilets, water points, schools and other critical infrastructure.[13] Over 100 community members and 165 students of local universities were engaged in creating data and facilitating knowledge transfer on community-based flood and disaster issues.[13] The World Bank's Tanzania Urban Resilience Program (TURP) used the data to develop detailed flood models for Dar es Salaam, with building footprint data combined with information on elevation and drainage systems allowing for the creation of highly accurate inundation maps that show which specific buildings and areas are likely to be affected by flooding of different magnitudes.[6] The community mapped data supports flood modeling on a level of detail that is currently inaccessible in many data-scarce environments.[12] The data collected enables people across all levels of society to improve flood mitigation plans and raise awareness and resiliency to natural threats.[1] The maps provide valuable information about likely flood risk in vulnerable neighborhoods and reflect the knowledge of those most directly affected.[9] Community members are now better informed about the risks in flood-prone areas, are able to access up-to-date community-based maps to get a better sense of the extent and impact of a flood, and know who to contact in order to coordinate response actions.[14] The addition of Mjumbe boundaries and more accurate, detailed flood data from ODK from the second phase continues to inform and advise community members and government officials on focus areas for flood mitigation planning.[8]

The project created data used in government risk assessments.[3] At a later stage, the data collected and edited in OpenStreetMap will be used in InaSAFE (an open-source software used in QGIS) to help model disaster scenarios and will provide information to assist in allowing for better planning and response to floods by government authorities/offices.[17] The raw data produced is fed into publicly accessible tools such as OpenStreetMap and InaSAFE, two "wiki" sites for the cartography and disaster relief communities.[11] Sourcing information from OpenStreetMap and InaSAFE, authorities can identify areas at greatest risk of flooding and simulate disaster scenarios.[11] Residents can locate latent water accumulation zones with drone-led aerial surveys of local topography.[11] Residents can now know ahead of time which structures in their neighborhood stand to be impacted most in the event of disaster, and make a credible case for more resources when disaster strikes again.[11] The project created the most detailed and comprehensive map of Dar es Salaam in existence, with this open dataset available for use by government agencies, NGOs, researchers, and the private sector to support a wide range of development and resilience-building activities.[6] All data generated by this project is freely and publicly available and subsequently integrated into various governmental organizations, such as the National Bureau of Statistics and the Department for Disaster Management.[16] The Dar es Salaam Multi-Agency Emergency Response Team (DarMAERT) uses the atlas to support field response during disasters, which was created back in 2018.[7]

Based on the printed maps produced from the first phase, local people are establishing waste management initiatives to clean blocked drains and educate residents on the detrimental impact of littering.[8] Community members explained how the first phase maps have been used to inform community cleanup initiatives to remove waste from blocked drains.[8] The mapping contributes to better urban planning, better drainage and maintenance, and better community waste management.[2] Green WastePro LTD – a trash collection company in Dar es Salaam – worked with the team to develop a dataset to enable tracking and locating of their clients for better service and revenue, with the company's revenue increasing significantly as they started using the datasets as a result of the training and support received.[15] The project is harnessing the power of community to help local authorities like Ward Executive Officers better allocate resources – be it to repair a clogged water pipe or remove waste build-up from a flood-prone area – more effectively and cheaply than ever before.[11] The data will further be used to inform other initiatives by the Bank's urban resilience umbrella team in Tanzania—its vast portfolio includes participatory climate risk plans and emergency planning for disaster response.[5]

The initiative has been training students in Dar es Salaam and equipping them with industrial and technical skills for the 21st Century while generating vital high-precision, low-cost data for flood prediction and preparedness.[1] The skills acquired by mappers are widely applicable to a number of areas, contributing to their ability to diversify their livelihood options and adapt to change.[14] Volunteers are making direct contributions to the safety of their communities and gaining new skills along the way.[11] Building on the inclusive and participatory model to resilience-building, TURP supported the Resilience Academy, which was first launched in 2019, and has since enabled 1,400 young Tanzanians to develop skills in data collection, community engagement, and mapping.[9] A GFDRR-funded pilot supported Resilience Academy participants to produce detailed tree-cover maps of Dar es Salaam that have helped urban planners identify inequities in canopy coverage across the city.[9] The project addressed sustainability by building local capacity at Ardhi University, creating a cohort of trained students and faculty who can continue the mapping work.[6] Edward Anderson, Senior Technology & Innovation Specialist at the World Bank and manager of GFDRR's support of the initiative, says "We're not delivering risk maps to clients, we are building up capacity and institutions to do maps better and forever."[11] Francis Ghesquiere, Head of GFDRR, explains "Tanzanians are taking the lead on Ramani Huria, which not only ensures its sustainability, but also paves the way for the next generation of disaster risk managers, computer scientists, and cartographers."[11]

Climate Adaptation Relevance

Dar es Salaam is vulnerable to floods, rising sea-levels, coastal erosion, water scarcity, and outbreaks of diseases, with the city of an estimated 6,368,000 people particularly vulnerable to climate change effects, caused among other things by poor planning and infrastructure, construction in hazardous lands and riparian areas.[15] Severe flooding in December 2011 - January 2012 displaced at least 10,000 people and caused 40 deaths.[1] Heavy rains in April 2014 led to widespread flooding and infrastructure damage.[1] In Dar es Salaam, floods in 2009, 2011, and 2014 caused injury and loss of life, while also severely impacting diverse sectors including transportation, energy, and social infrastructures such as schools and health facilities.[16] The city is home to nearly 5 million inhabitants, many of whom face the likelihood of flooding during Tanzania's two rainy seasons (in March/April and November).[5] In the unplanned and informal settlements that abound in Dar es Salaam, flooding causes heavy losses in livelihoods and infrastructure, with flooded homes and roads causing at least nine casualties in one month.[14] Around 70% of city residents live in informal settlements, and urbanization is largely unplanned.[1] An estimated 70-80 percent of residents live in unplanned settlements.[16] Buguruni kwa Mkanda and Tandale are among Dar es Salaam's countless unplanned, under-resourced, and largely unmapped informal settlements that sprawl across 80% of the city and suffer most when disaster strikes.[11] Tanzania is the most flood-affected country in East Africa, and city governments across the country are underprepared to meet the challenges of urbanization, including the increased vulnerability to climate-related hazards.[16]

Business Analysis

The use of free and open-source software and local devices (students trained on smartphones) means that everything needed to continue the project and keep data updated as the city changes is already available in the community.[14] The project demonstrated how low-cost tools such as OpenStreetMap, drones and in-situ sensors can be scaled and provide a platform for innovation.[13] Data acquisition based on community mapping can be affordable, comprehensible, quality assured and open source, making it applicable in resource-strained contexts.[12] The community mapping approach is appropriate for datasets that do not require extensive training, such as flood extent surveys where it is possible to cross-validate the quality of reports given a suitable number and density of data points.[12] More technically advanced features such as dimensions of urban drainage system elements still require trained mappers to create data of sufficient quality.[12] The approach proposed is based on proactive engagement of the local community that is trained to collect high quantities of flood-related data which allows for extensive flood model development and validation in an affordable way.[12] The framework for urban flood modeling with community mapped data was demonstrated and validated on a case study in Dar es Salaam, Tanzania.[12] The hypothesis was tested by developing a hydrodynamic model including detailed schematization of a community mapped drainage network and comparing the simulated flood depth with citizen's reports on flood depth for models run with and without the community mapped drainage network.[12]

The World Bank is the main financier of the project, and Humanitarian OpenStreetMap Team (HOT) is the primary organization managing projects.[4] The initiative is supported by the World Bank through its Global Facility for Disaster Risk and Recovery (GFDRR) and its partners.[11] GFDRR supported the initiative, a community-mapping project that trained university students and local community members to create open-source maps of Dar es Salaam's most flood-prone areas.[9] Stakeholders include the Commission of Science and Technology (COSTECH), Dar es Salaam City Council, Global Facility for Disaster Reduction and Recovery (GFDRR), and the Red Cross.[4] The World Bank has formed a partnership with the UK Department for International Development (DFID) and established the Tanzania Urban Resilience Program (TURP) in response to flooding issues.[16] The Humanitarian OpenStreetMap Team with its local partner OpenMap Development Tanzania has been contracted to build upon datasets collected during the first and second phases that started in 2015 and 2017 respectively.[16] HOT and OMDTZ led a series of short urban mapping campaigns over a 6-month period starting in July 2020 that included verification and update of OpenStreetMap (OSM) data for COVID-19 hotspot analysis, remote digitization of buildings, and community flood history mapping.[16]

Building on the foundation of the initiative, the Zuia Mafuriko project was initiated to specifically leverage this newly available data for flood resilience and early action, meaning "Stop Floods" in Swahili, implemented by the Tanzanian Red Cross Society (TRCS) in collaboration with the Climate Centre and the World Bank.[6] The Zuia Mafuriko project focuses on two flood-prone wards: Tandale and Mwananyamala, which were selected based on their high vulnerability to flooding and the availability of detailed community-mapped data from the project.[6] Consultancy contract for community upgrading in Tandale and Msimbazi Basin was signed in June 2019.[18] The innovative, citizen-based participatory approach has already started to spread to other cities (such as Stone Town, Zanzibar) which have adopted the participatory mapping methods pioneered by the initiative.[13] The project was showcased during the Africa Open Data Conference from September 2–5, 2016, which included over 450 participants from African governments.[13] At the event, copies of the Risk Profile Atlas were disseminated and an agreement made to form committees on harmonizing data across Dar es Salaam, providing a foundation for a national framework of urban open data sharing.[13] Ten additional workshops were delivered in collaboration with CSOs and universities—particularly the Tanzanian Red Cross Society, one of the key implementing partners—to establish community-led emergency response mechanisms in urban areas.[13] The project was shortlisted for the "City to City Barcelona FAD Award" in 2018.[4] One of Humanitarian OpenStreetMap Team's biggest multi-year projects wrapped up in 2019.[3] All datasets, maps, tools, learning materials and documentation of the project are being transferred to the Resilience Academy, who will be carrying the project forward.[15] OMDTZ has been enriching OpenStreetMap through anticipatory actions and mapathons where volunteers update maps in collaboration with partners like dLab and CartONG.[7] OMDTZ received funding from the Zayed Sustainability Prize with focus on working with communities and youth to update data, test new mapping methods, and push for digital tools that save lives when every second counts.[7] The use of 360-degree imagery via Mapillary has enabled AI to detect features like traffic signs that are later added to OpenStreetMap.[7] Much of the Atlas data was collected between 2015 and 2020, and rapid urban growth has left some areas unmapped or outdated.[7]

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