Catchment Flash Flood Guidance

The figure shows hourly threshold runoff estimates computed on the basis of global data. Threshold runoff in this case is the volume of hourly rainfall over the delineated watersheds that is just enough to cause bankfull flows at the outlet of the draining stream. Combined with current soil moisture conditions, threshold runoff provides the basis for estimating flash flood guidance (FFG). The above estimates of threshold runoff are based on watershed analysis with 1-km global digital terrain elevation data, GIS delineation of streams, and nominal values of regional stream cross-sectional properties.

Central America Mitigation Initiative (CAMI)
Regional Operational Flash Flood Guidance