EO-based hazard flooding maps - South Sudan, 2012-2024

Field Name
Description

Use Case Name

Flooding and health care service disruption in South Sudan.

Dataset Name

EO-based hazard flooding maps. 

Dataset Description

The dataset covers the period 2012–2024 and provides hazard flooding maps derived from VIIRS data at 375 m/pixel, where each pixel represents the fraction of water coverage. The maps cover an area of interest (AOI) of 189.856 km2  (almost 30% of total South Sudan surface). A hydrologically conditioned Digital Elevation Model (HydroDEM) combined with the HAND algorithm was used to generate binary flood maps at 90 m/pixel resolution. Each product represents a five-day composite, capturing temporal dynamics of flooded areas. The provided hazard maps have two layers: flood frequency (how often a pixel was flooded in a year) and flood duration (how many days it was inundated that year). 

Temporal Domain
2012-2024

Spatial Domain
South Sudan (bounding box ranging from longitude 28.5942ºE to 4.8367ºE and latitude 31.8383ºN to 9.6283ºN, in EPSG:4326).

Key Variables/Indicators
Flood frequency: how often a pixel was flooded in a year. Flood duration: number of days a pixel was flooded in a year.

Data Format
GeoTIFF

Souce Data
VIIRS, HydroDEM

Limitations/Assumptions

VIIRS’ moderate spatial resolution (375 m/pixel) restricts its ability to capture small or narrow inundated areas, especially in urban or complex terrains. As an optical–infrared instrument, VIIRS cannot penetrate clouds, making flood detection difficult during cloudy or rainy periods when floods are most likely to occur. Mixed land–water pixels further introduce uncertainty, particularly along flood boundaries or in vegetated regions.