Ramani Huria, "Open Map" in Swahili, is a HOT Tanzania project focused on mapping Dar es Salaam to inform flood prevention plans.
Dar es Salaam is one of the fastest growing cities in Africa, with an annual population growth of over 5.7%. In 2002 there were approximately 2.5 million inhabitants, increasing to 4.4 million in 2012, and currently estimated at over 5.5 million. The population is expected to exceed 10 million by 2040, making Dar es Salaam a megacity. Urbanization is largely unplanned, and around 70% of city residents live in informal settlements. The poorest citizens who settle in these areas not only have less access to basic services, but are also the most exposed to natural hazards.
Severe flooding in December 2011 - January 2012 displaced at least 10,000 people in Dar es Salaam and caused 40 deaths. Heavy rains in April 2014 also led to widespread flooding and infrastructure damage. Climate change is expected to exacerbate these trends, as Tanzania’s coastal region is likely to experience heavier, more concentrated rainfall events. Increasing frequency of floods, landslides, and other hazards is expected to impact the most fragile, unplanned parts of the city.
In 2015 HOT began an initiative to mapping infrastructure data in various parts of Dar es Salaam. Now in its second phase, Ramani Huria 2.0, which began in 2017, is combining exposure data and flood hazard data to conduct risk analysis of potential future disasters. The team are using community mapping techniques to engage with local leaders and teach community inhabitants free, open source data collection tools from their smartphones. The data collected is enabling people across all levels of society to improve flood mitigation plans and raise awareness and resiliency to natural threats.