Population density = the average number of people living in each square kilometre.
This has been calculated using population data for each sub-ward (obtained from the Dar es Salaam municipalities), and then dividing the population of each sub-ward by the area (km2). The categories of LOW DENSITY, MEDIUM DENSITY and HIGH DENSITY are classified using tertile distribution, where each of the three groups contain one third of the total population of Dar es Salaam.
Population density is useful for determining the level of demand for solutions.
High Density - over 15,750 people per km2
Medium Density - 5,950 - 15,749 people per km2
Low Density - Below 5,949 people per km2
Accessibility = Distance from vehicular access roads (+/- 50m)
The distance of 50 metres has been selected as the reasonable distance to provide sanitation services to areas NOT-SERVED by centralised infrastructure, by using a truck (E.g. FSM pit-latrine emptying via vacuum truck, solid waste collection via truck, water supply via tanker).
Road access is a useful for shortlisting options based on solution logistics.
NOTE: The area boundary of this category has been restricted to include only “urban” areas of Dar es Salaam, as “peri-urban” areas have different accessibility challenges.
The boundary of urban areas has been taken from the “Tanzania: Urban Extents” Map (source map can be found in our downloads section), which illustrate the shape and area of urbanised spaces. Urbanised localities are defined as places with 5,000 or more inhabitants that are delineated by stable night-time lights. For poorly lit areas, alternate sources are used to estimate the extent of cities.
The road network has been downloaded from the Open Street Map Project via the Geofabrik server. This data may be incomplete and only represents the roads which have been mapped by the Open Street Map community. The “paths and walk ways” have been removed from the larger road file before analysis.
In addition to the selected characteristics of Density, Accessibility and Income – context-specific local data is essential for selecting the most suitable solutions for specific areas, E.g. Flood prone or high ground water areas will require certain solutions.
Overlaying additional local data will also help identify areas requiring immediate intervention.
The layers showing cholera, flood prone and high ground water areas have been provided by SanMap.org. More details of the data collection methodology can be found at their website.
The Water Supply Network, Sewer Network and Waste Water Treatment Pond locations are provided by DAWASA.
Household income is useful for shortlisting options based on solution affordability or users’ ability to pay for services.
As household income levels in Dar es Salaam are so varied – and accurate income data is difficult to obtain – it was not possible to overlay this category onto the map. Assumptions at such a large scale are not helpful, because when we take a closer look at each ward, it is common to find a range of different income levels at sub-ward and even at household level. Additionally, socio-economic conditions throughout the city are constantly changing, at a pace too fast to keep up with.
Therefore you are required to self-select the most realistic income category for your area of interest (low-income, medium-income and high-income).
Survey completed May 2015 for further information please contact DAWASA
No/Limited Road Access
Cholera & Flood Prone
High Ground Water
Water Supply Network
Wastewater Treatment Ponds