Sel Riski How Is It Calculated?
Flood risk estimation sits at the intersection of meteorology, hydrology, and civil engineering. Total rainfall volume, precipitation intensity per hour, and soil permeability determine whether water infiltrates or creates flash runoff.
This calculator analyzes Precipitation Rate (in/hr or mm/hr) and the Runoff Coefficient. Impervious pavement produces runoff coefficients up to 0.95, whereas absorbent forest soils stay near 0.20.
Rainfall exceeding 2 inches (50 mm) per hour signals acute flash flood emergencies. Cumulative runoff over 2 inches quickly overwhelms drainage basins.
This tool helps homeowners, contractors, and municipal personnel take proactive drainage precautions before heavy storms hit.