In Pursuit of Greener Cities: GeoData for Urban Landscape Development Opportunities in Dar Es Salaam
By Aisha Hamisi
Efforts to achieve sustainable urban development in Dar es Salaam by identifying opportunities for public landscaping and urban forestry projects that can create benefits in urban environments
Dar es Salaam is Tanzania’s largest city and one of Africa’s fastest-growing cities in Africa, with a population of over 6 million people. Dar es Salaam has an estimated 70% of its urban population living in unplanned settlements. From 2002 to 2012, the average annual population growth rate was 5.8 percent. By 2030, it is expected to be a megacity with a population of more than 10 million people.
With this rate of urban growth, there are always demands for infrastructure, service provision, proper urban planning, and so on, which is difficult for authorities to keep up with the pace of growth, especially when data is limited to make informed decisions. Dar es Salaam’s rapid urban growth is accompanied by issues of uncontrolled urban planning, which leads to poor drainage systems, waste management challenges, water pollution, poor landscape management, and so on.
Through the Tanzania Urban Resilience Program, the World Bank in Tanzania has been supporting efforts to fill the existing data gaps that limit accurate assessment of challenges and informed decisions; this also includes the collection of geospatial data for different purposes. Open Map Development Tanzania, in collaboration with Resilience Academy, worked with university students to support data collection to inform opportunities and suitability of urban greening, Sustainable Urban Drainage Systems (SuDS), and open space development across Dar es Salaam through World Bank funding.
Student mappers were trained to gather various ground truthing data from samples of six specified areas of land uses as listed below, in order to acquire data that will inform the identification of opportunities for urban greening and landscape development.
- Residential areas: The information collected on residential includes the structure of buildings and their uses i.e if the building is commercial-residential. Other architectural details include the roofing type such as flat, gable, mono-pitch, or double-pitch, and the material i.e iron sheet, thatch, stone, wood, textiles, and concrete, and the structure’s state. This information is to understand the details of the settlement structure and its composition.
- Open Spaces: The information collected in open spaces includes location, ownership (public/private), current use, services available in the vicinity, and so on. A total of 121 open spaces were collected. The analysis of data collected indicates that 31% of open spaces are used as urban farmland, followed by brownfields (26%), landfills (13%), gardens (12%), recreation grounds (6%), cemeteries (5%), parking (4%), forestry (3%), and commercial (1%). This suggests that, despite the fact that grass is the most common surface, agriculture and brownfields make the soil more exposed to erosion. The analysis can be used by urban planners to assess and make decisions about the revised urban landscape design and used for a greener city.
- Boreholes: The information gathered includes the coordinates of the boreholes, the region, the district, and the ward and sub ward. And the image of the boreholes can be used as proof to further explain who the borehole’s owner is.
- Highway and natural drains; Information on road type, use, and condition i.e good, Intermediate, or bad. This data is essential when analyzing or proposing the uses of open spaces as the accessibility of the space plays a greater role in what uses will be conducive.
- The extent of littering: This was based on the observation of the situation i.e students observed if the letter is few, many, or heavily littered with significant accumulation of waste, the type of litter found in the area (biodegradable waste, like food flowers), general waste (like food wrappers, paper), plastic waste (nylon), hazardous waste (medical, solvent bottles), and construction waste (demolition waste).
- Tributaries; the tributaries were surveyed in the lower, middle, and high portions of the rivers to understand the direction of the drain, its status, and if it has a tendency to overflow or not, students were required to go along the tributaries and also seek information from the residents along the channel to be able to record the reliable data. Understanding the status of these river channels helps to analyze the situation of flooding in the area, tree planting actions, etc.
The project provided 20 university students with digital geospatial knowledge and skills; the ability to conduct field data collection, the use of open mobile data collection tools, the ability to interact with community members, and most importantly, how data can inform urban greening and space management efforts.
“Before this industrial training, I always assumed that urban greening projects only involved planting trees in city open spaces, but there is a lot more to it, such as sustainable urban drainage systems, and open space development, I am proud to be a part of this.” Glory Dinesh, Student; Ardhi University.
The data collected will aid in determining which areas will be prioritized for the start of urban greening projects. Urban greening does more than just improve the appearance of towns and cities; it transforms them into environments that benefit both people and nature. Creating new green spaces reduces air pollution, floods, and provides new habitats for local wildlife while also bringing communities together. Also, it creates fantastic opportunities to drive economic growth, help businesses thrive, and boost tourism in the city.