A 6-hour Unit Hydrograph (UH) of a catchment is triangular

A 6-hour Unit Hydrograph (UH) of a catchment is triangular in shape with a total time base of 36 hours and a peak discharge of 18 m³ /s. The area of the catchment (in sq. km) is

Volume of run off = Area of hydrograph

=	1	× 18 × (36 × 60 × 60) = 1166400 m²
	2

Depth of run off = 1 cm =	1	m
	100

Area of catchment

=	Volume of run off	×	1
	Depth of run off		(1000)²

=	1166400	×	1	≈ 117 km²
	1/100		(1000)²