Flood Mapping

Since 2015, Ramani Huria has been tackling the issue of flooding in Dar es Salaam to reduce flooding and encourage sustainable water resource management. Now in the second phase of the project, Ramani Huria 2.0 is focusing on mapping the most flood prone Wards of Dar Es Salaam, such as Kigogo and Hananasif Wards, to produce flood extent information which will later be used to inform decision making and flood mitigation plans. The Ramani Huria team begin the community mapping process by introducing themselves to the ward officers, explaining the project and providing an introductory letter addressed Subward officials. Next, the team are introduced to the Wajumbe local leaders who operate at the most granular level of administration system that exists in Dar es Salaam.

This week we visited the field team this week to see the amazing work that is being done by the team.We were excited to meet one of the community members who has been involved in mapping since 2015 when Ramani Huria 1.0 was implemented.

“I participated in Ramani Huria 1.0 when we were using field papers and GPS devices to move around to collect information. It was time consuming and you may have lost data during the process, but now that we’re using smartphones to collect data it’s quicker and you’re not likely to lose data in the process” – Hafidhi Hamza, Community Member

   

LEFT PHOTO; Interview with Community Mapper from Ramani Huria 1.0

RIGHT PHOTO; Drainage blockage caused by littering behind a resident’s house in Kigogo Ward

The data collected from Ramani Huria is helping inform decision makers at all levels of society on flood mitigation measures to tackle current pain points. Already, based on the printed maps produced from Ramani Huria 1.0, local people are establishing waste management initiatives to clean blocked drains and educate residents on the detrimental impact of littering. As population increases and the level of waste produced multiplies, maps such as those produced by the Ramani Huria team are imperative to raising awareness of flood causes, mitigation measures and response plans. The Ramani Huria team initially started to use OpenMapKit for data collection and mapped Hananasif ward and part of Kigogo ward. The team then realised that it is more difficult to analyse data collected in polygon format, especially when producing heat maps you need the data to be collected as points, so the team immediately switched to using Open Data Kit (ODK). ODK allows them to collect data points and fill out the survey to establish the trend of flooding in this particular ward.

The data collection process was conducted in the following manner –

Ten cell leaders (Wajumbe) would select a community member who owned a smartphone so that:

1. The phone could be installed with Open Data Kit (ODK) Collect.
2. They could make sure that the survey form is downloaded from the server; www.turkus.net (the survey is written in Swahili to avoid language barriers and is user friendly).
3. The GPS accuracy of the device could be checked (usually less than 4 meters).
4. A community member could be trained by the Ramani Huria team on how to collect data using ODK
5. ODK questions will be elaborated to community members to make sure they collect the desired information.

After making sure that community members are equipped with the data collection skills needed, field work commences. A community member is provided with scratch cards (to buy internet packages) and a power bank.

 

PHOTOS; Community member and Mjumbe conduct ODK flood extent surveys with local residents

[symple_testimonial by=”” fade_in=”false”] “Ramani Huria 2.0 is far better than RH1 because in this phase we conduct community surveys and a community member is asked questions such as if the residents of a particular house had experienced flooding or not. This can provide reliable and documented information to the government” – Hafidhi Hamza, Community Member[/symple_testimonial]

The field team then demonstrated how they analyse field data to make sure that everything has been covered before moving on to the next ward. Data is visualized according to Mjumbe leaders area of jurisdiction and within each cluster you can determine if all of the survey questions have been covered.

The team are also able to visualize clearly respondents answers to questions about the history of flooding in their area. Respondents are asked questions such as, “have you ever experienced flooding?”, “how deep was the flood water?”, “have you moved settlement because of flooding?”, “what do you think caused the flooding?”.

The team create a new dataset for each year flooding is reported so that flood impact can easily be visualized by year.

PHOTO; ODK survey form questioning the depth of flooding

Maps like the one above demonstrate clearly areas prone for flooding. Already, the impact of Ramani Huria 1.0 can be seen. Community members explained how the RH 1.0 maps have been used to inform community cleanup initiatives to remove waste from blocked drains. The addition of Mjumbe boundaries and more accurate, detailed flood data from ODK from Ramani Huria 2.0 will continue to inform and advise community members and government officials on focus areas for flood mitigation planning.