ECO-DRR - River Flood frequency

EcoDRR global classification scheme based on spatial combination of ecosystem coverage and natural hazard physical exposure.

The physical exposure data-set shows the product of hazard frequency and people exposed to this hazard in the same 100 square kilometer cell.

For a specific natural hazard, a 0.01 degree resolution raster is generated, showing hazard annual frequency weighted with portion of pixel potentially affected.

The original flood hazard model includes various return period. The annual frequency is a sum of all frequencies obtained from these return periods layers.

Sources:

The dataset uses a probabilistic approach for modelling riverine flood of major river basins around the globe. This has been possible after compiling a global database of stream-flow data, merging different sources and gathering more than 8000 stations over the globe in order to calculate the range of possible discharges from very low to the maximum possible scales at different locations along the rivers. The calculated discharges were introduced in the river sections to model water levels downstream. This procedure allowed for the determination of stochastic event-sets of riverine floods from which hazard maps for several return periods (25, 50, 100, 200, 500, 1000 years) were obtained. The hazard maps are developed at 1kmx1km resolution and have been validated against satellite flood footprints from Dartmouth Flood Observatory archive.

This product was designed by UNEP/GRID-Europe and CIMA Research Foundation for the Global Assessment Report on Risk Reduction (GAR). It was modeled using global data. Credit: UNEP/GRID-Europe and CIMA Research Foundation.