CFM CFM Hydrology & Hydraulics

Question 1

The '100-year flood' is best described as a flood that has a:

Accepted Answer

1% chance of being equaled or exceeded in any given year

Answer

Recurrence interval of exactly 100 years

Answer

1% chance of occurring once per century

Answer

100-year return period with no annual variation

Question 2

Which hydrologic method is most commonly used in FEMA flood studies to estimate peak discharge for small urban watersheds?

Accepted Answer

TR-55 (SCS Curve Number Method)

Answer

Manning's Equation

Answer

Rational Method

Answer

Muskingum Routing

Question 3

In hydraulic analysis, Manning's Equation is used to calculate:

Accepted Answer

Open-channel flow velocity and discharge

Answer

Rainfall runoff volume

Answer

Sediment transport rates

Answer

Time of concentration

Question 4

The HEC-RAS software model is primarily used in flood studies to perform:

Accepted Answer

One-dimensional steady and unsteady open-channel hydraulic analysis

Answer

Rainfall-runoff simulation

Answer

Two-dimensional groundwater modeling

Answer

Coastal wave height prediction

Question 5

What does the 'regulatory floodway' represent in a hydraulic study?

Accepted Answer

The channel and adjacent floodplain reserved to carry base flood flows without increasing BFE by more than 1 foot

Answer

The entire 100-year floodplain

Answer

The area between the 10-year and 100-year flood boundaries

Answer

The area subject to wave action

Question 6

Which parameter in the SCS Curve Number method most directly reflects soil type and land use?

Accepted Answer

Curve Number (CN)

Answer

Time of concentration (Tc)

Answer

Lag time

Answer

Hydraulic radius