ESA title

FloodSENS: Smart Sensing of Floods

Data Segment
  • Data Analytics, Insights & Applications
FloodSENS aims to create an algorithm that efficiently reconstructs flooded areas under partial cloud cover in optical satellite images, using Machine Learning and auxiliary high-resolution data from drones, digital elevation models, and water flow algorithms. This activity is being developed by the Luxembourg-based company RSS-Hydro and in partnership with ESA’s InCubed program.
Objectives of the Product

Floods are one of the most devastating natural disasters, accounting for the highest insured and uninsured losses annually, as well as costing many lives. With climate change possibly intensifying the hydrological cycle, the frequency and magnitude of extreme hydro-meteorological events, and therefore the risk of floods, are projected to continue to increase. This will be of devastating consequences, as it would put a greater strain on humanitarian response efforts and future financial risk of the global (re)insurance market.

Earth Observation data-based solutions currently provide a more advanced alternative to traditional ground-based flood monitoring methods or computer models, namely the ability to cover wider areas, frequent revisit times, abundant open access data and long historic image archives. However, there are still important challenges left unaddressed that compromise the quality and reliability of the data, such as the persistent cloud cover during floods, latency issues and the problem of getting abundant high-definition images under less favorable weather conditions and at night.

FloodSENS overcomes these issues by developing a flood mapping application that is capable of integrating a wider range of EO datasets and drone data using Machine Learning. This novel application being developed to market, seeks to efficiently reconstruct flooded areas under partial cloud cover in satellite images, thus creating far more reliable flood risk assessments and flood mapping during emergencies.


Customers and their Needs

FloodSENS is especially important for disaster response agencies at regional, national, and international level, who are keen to utilize the proliferation of open satellite data for flood mapping during emergencies. Additionally, in the insurance and re-insurance markets, stakeholders are interested in EO data to map the flood hazard of high-impact events and on a historical basis to understand risk exposure and the changing nature of it.

In the case of the flood disaster response markets, customers often have to deal with optical satellite imagery that is partly covered by clouds during flood events, where the data resolution is too low to allow for local scale flood analysis and they often lack resources to deal with complex EO image analysis. This inevitably compromises the humanitarian relief efforts as it leads to incomplete estimation of flood areas and thus misrepresentation of the real impact of the flood. The (re)insurance market struggles mainly with assessing the extent of flooding for high impact events, as well as understanding the potential flood risk exposure at a local-scale. This is due to many factors, including those referred to above, along with high costs in conducting on-site inspections, using incomplete EO data archives to build historical records and prediction models, and often lack of EO specialists.


Targeted customer/users countries

FloodSENS is targeting both the humanitarian and disaster relief organizations, as well as the global (re)insurance market, with the aim of having the application work in diverse environments worldwide.

At an initial stage, as representatives of their respective customer markets, FloodSENS will have as partners and testing customers the United Nations World Food Programme (UN WFP), the National Disasters Management Institute of Mozambique (INGC) and Willis Re (re)insurance broker through Willis Towers Watson (WTW).


Product description

FloodSENS consists of a fully automated Machine Learning-based flood mapping algorithm, whose main characteristics include:

  • Ability to reconstruct flooding below clouds in optical satellite images of floods
  • Ability to reconstruct flooding at higher resolution than the image resolution

The schematic below, illustrates the FloodSENS algorithm structure, the overall architecture, and the key submodules.

The main modules that make up the full package of the development FloodSENS product are:

  • FloodSENS software Module: dealing with image & auxiliary data pre-processing & adaptation, ML model training and prediction
  • Service Validation Process: validation of processed flood maps with its project partners.
  • Business Development/Deployment using WASDI Module: the FloodSENS app will be deployed on WASDI, a multi-cloud EO processing platform, for on-demand and user-friendly execution of FloodSENS by customers worldwide.

FloodSENS seeks to resolve some of the biggest challenges in utilizing EO data for flood mapping, namely the cloud cover in images and low resolution. In fact, no mapping app exists on the market that scales between drone and optical satellite imagery, while overcoming the major limitations of optical EO imagery during floods.

This is exactly what the innovation of FloodSENS is addressing by using a machine learning algorithm to reconstruct flooding under clouds in partially clouded optical satellite images. The final map output will not only have an accurate reconstructed flood map, but is also of higher spatial resolution than the original satellite flood image.


Added Value

The added value of FloodSENS centers around two major innovations:

  1. The ability to reconstruct flood area under clouds in optical satellite images. This allows to valorize flood images with high cloud cover and can identify potentially missing flood areas. It also builds a more accurate and reliable historical record of flooded areas.
  2. Add custom map features via agile development with specific  customers/users. This can include flood depth mapping capability, explicit map uncertainty representation, customer-led map creation and visualization., so map data are also much easier to interpret by non-experts.

In fact, for both Europe and the wider world, future Earth Observation-based and ML-powered apps would add considerable value to the existing products of the free Copernicus Emergency Management Service (EMS) and beyond. RSS-Hydro’s FloodSENS will place itself at the intersection of these two fields (EO technologies and AI/ML application tools) being at the forefront of future EO-enabled innovative solutions, to make a difference in allowing a much more effective disaster response.

The first half of 2019 was a devastating period for many countries in southeast Africa. After Cyclone Idai at the start of the year destroyed many places, particularly the port city of Beira, Cyclone Kenneth ravaged northern Mozambique. Entire villages were destroyed and almost one million people were at risk in the area. This partial cloud-free subset of a Sentinel-2 image of May 3 2019 shows large areas under water in Pemba, regional capital of Cabo Delgado state, which experienced more than 2 m of rain and flooding. FloodSENS will render more optical imagery like this one usable during floods by reconstructing flooded areas under cloudy skies.

Current Status

Development work and iterative testing on several testcases, located in different parts of the globe (e.g. Mozambique, Balaton region, Greece, Bremen) are ongoing. RSS-Hydro uses Open Street Map (OSM) data as reference data, and also selected official Sentinel-1 SAR-based flood maps from the Copernicus EMS. The team has now tested a number of use cases and have a robust plan forward. Furthermore, RSS-Hydro has completed the automation of all data pre-processing and training steps and is now also able to fully utilize the Azure platform for development and inference. We have built a first deployable FloodSENS version for WASDI, which is not publicly released yet. WASDI is the online cloud computing platform that allows location-specific inference as well as validation by our end-user partners. The next steps now are to test the FloodSENS architecture for transferability and to continue working on customer-led flood use cases. Together with our partner end-users, we are developing user success stories to get a better understanding of possible sector-specific added values of FloodSENS.

Prime Contractor Company
RSS-Hydro
Luxembourg Flag Luxembourg
Contractor Project Manager
Name
Guy Schumann
Address
100, route de Volmerange, L-3593 Dudelange Luxembourg
Contacts

gschumann@rss-hydro.lu

+352 206005 6301

ESA Technical Officer
Name
Bertrand Le Saux
Contacts

Bertrand.Le.Saux@esa.int

Current activities