Drones helping to understand flood risk in Tanzania

The Tanzania Urban Resilience Program is using an innovative combination of Light Detection and Range (LiDAR) UAV (or drone) surveying and bathometric surveying to support flood modelling within the flood-prone Msimbazi river basin. Outputs will be used to guide river upgrades that will improve Dar es Salaam’s resilience to flooding.

#EndPoverty

[WorldBank]

Video Transcript

Frederick Mbuya, Uhuru Labs Drone Consultant: We are standing on the exit of the Msimbazi Basin which dumps out in to the ocean. During heavy rains a lot of the water is supposed to come out of the Msimbazi, out of the basin and empty out into the ocean, but for various reasons; being mangroves, solid waste and other things it is not happening. It gets backed up, we have heavy rains, and we have very serious floods around the basin of Msimbazi.

Mussa Natty, Former Municipal Director – Urban Specialist: The poor people that live within the Msimbazi valley are the ones who are the most vulnerable.

Caption:

To make the city more resilient to flooding, better data of the river basin was needed.

Deogratias Minja, World Bank Urban Planning Consultant: We want to solve this problem of flooding, so we try to come up with a good solution. We are doing what we call bathymetric surveys, in order to get exactly the profile of the river.

Frederick Mbuya, Uhuru Labs Drone Consultant: We here in Tanzania have built up an excellent knowledge base on the use of drones, and it is really great for getting your surface model, which actually means what we capture is the top of buildings, and the top of vegetation, we don’t actually go all the way to the ground.

Caption:

To create better flood models the team needed more accurate data.

Deogratias Minja, World Bank Urban Planning Consultant: 3D models of the valley without any tree, any building or anything.

Frederick Mbuya, Uhuru Labs Drone Consultant: The golden standard is to use LIDAR, which penetrates all the vegetation and gives us the actual ground depth. There are very few people around the world who are using drone mounted LIDAR systems, so that is what we are doing today, we have brought in our colleagues from the Netherlands. We went out, we found experts, they are here now doing it, but one thing we do very carefully is shadow them, and make sure we learn as much as possible about it.

Roeland de Zeeuw, Shore Monitoring & Research: LIDAR is just laser beams, sent out and is recorded back again. You know exactly where that building is, or where that tree is relative to your sensor. We just remove them all and then we have the digital terrain model, and what measures have to be taken, to make this area more resilient.

Caption:

Teams also surveyed the river by boat

and on foot to get accurate river depth levels

Deogratias Minja, World Bank Urban Planning Consultant: With this technology you can get the terrain of the river.

Frederick Mbuya, Uhuru Labs Drone Consultant: That allows us to plug it in to a computer, and say, “Ok, let’s say we have X amount of rainfall, and the tide is at this level. What exactly is going to happen?” And the only way to do that is with an accurate surface model.

Deogratias Minja, World Bank Urban Planning Consultant: It will give you a clear answer, how does the water pass through to the sea. That is the kind of calculation we need to understand in order to come up with a good solution. To be sustainable for the urban resilience of Dar es Salaam.

Mussa Natty, Former Municipal Director – Urban Specialist: For us this will give us something that is very, very sustainable, on the decision-making and management of the area, and also future land use planning.

Caption:

Urban resilience for a greener Tanzania
Urban resilience for a stronger Tanzania
Urban resilience for a safer Tanzania
Urban resilience for Tanzania

Logos:

Tanzania Urban Resilience Programme

World Bank Group

[naheemadebisi]

Good. Capacity building in Geospatial Technology in Africa will help in increasing the environmental monitoring tasks and the adaptability of the continent to disaster