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Dicken's formula for finding discharge is
Q=C⋅A3/5
Q=C⋅A3/4
Q=C⋅A4/5
none of the above
Q=C⋅A3/4
Dicken's formula is an empirical formula used to estimate the maximum flood discharge from a catchment area. It relates the peak flood discharge (Q) to the catchment area (A) using a constant (CD) that varies based on the geographical and climatic characteristics of the region.
Dicken's formula is an empirical formula used to estimate the maximum flood discharge from a catchment area. It relates the peak flood discharge (Q) to the catchment area (A) using a constant (CD) that varies based on the geographical and climatic characteristics of the region.
Q=CD⋅A3/4 — Dicken's formula for peak discharge estimation
The formula assumes that the peak discharge is proportional to a power of the catchment area. This relationship accounts for the fact that as the catchment size increases, the intensity and duration of rainfall causing peak discharge do not increase linearly, leading to the exponent being less than 1.
Dicken's formula is primarily used for basins in North and Central India.
The constant CD (Dicken's constant) depends on the rainfall intensity, soil type, and catchment characteristics.
It is an empirical method, meaning it is based on historical data rather than derived from physical fluid dynamics laws.
Other similar empirical formulas include Ryves formula (Q=C⋅A2/3) and Inglis formula.
Simple to apply
Requires minimal meteorological data
Regional specificity (limited accuracy outside North India)
Does not account for complex watershed parameters
Estimation of peak flood for small to medium drainage basins
Design of highway culverts and small bridges
Dicken's formula: Q=CD⋅A3/4
Ryves formula: Q=CR⋅A2/3
Inglis formula: Q=A+10.4124⋅A
Option A (A3/5) and C (A4/5) are incorrect exponents for this specific empirical relation.
B is correct — Dicken's formula for finding flood discharge is represented as Q=C⋅A3/4.
Always remember the exponents: Dicken uses 3/4, Ryves uses 2/3. Examiners frequently test the variation in these empirical coefficients.