Gallery · GIS analysis
Where water always returns.
The European Joint Research Centre classified every Landsat pixel on the planet, image by image, from 1984 to 2021: water or land. The result is a frequency map — from pink (occasional water) to blue (permanent water) — revealing the genuinely flood-prone areas around Cotonou, Lake Nokoué and the lower Ouémé valley.
Data: JRC Global Surface Water (Pekel et al., Nature 2016) — European Commission, Landsat 30 m, 1984-2021. Basemap: © OpenStreetMap, © CARTO.
From history to zoning
History
38 years of Landsat imagery, pixel by pixel: the JRC computes how often each 30 m footprint was detected as water — floods included.
Zoning
Regularly flooded areas stand out from permanent water bodies: a direct input for land-use plans, risk studies and siting decisions.
Modelling
To go from evidence to forecast, OHM WORKS surveys drone DTMs at under 5 cm vertical accuracy: fine runoff and flood simulation at neighbourhood or plot scale.
A flood-risk study for your area?
Municipalities, developers, insurers: we combine satellite history and centimetre-grade drone DTMs to precisely map flood hazard on your sites. Let's talk.