Weather

What is the primary purpose of sizing drainage structures and water impoundments?

• To increase soil permeability

• To manage runoff

• To promote groundwater recharge

• To prevent soil erosion

What does a hydrograph plot?

• Soil moisture content over time

• Runoff rate for a watershed versus time

• Atmospheric pressure variations

• Groundwater table depth changes

What characteristic of a watershed influences the time lapse from the start of rainfall until the peak rate of runoff occurs?

• Annual precipitation

• Soil type

• Drainage area

• Atmospheric pressure

How does the shape of a hydrograph vary with different rainfall events?

• It remains constant

• It becomes linear

• It varies depending on the watershed characteristic

• It becomes exponential

What does the rational method equation determine?

• Total precipitation volume

• Peak flow rate

• Soil moisture content

• Groundwater recharge rate

What organization provides actual values for specific watersheds to be used in calculations?

• National Weather Service

• National Resource Conservation Service

• Environmental Protection Agency

• Federal Emergency Management Agency

What influences the confidence in the output of the rational method?

• Soil pH levels

• Watershed size and variability

• Wind direction

• Atmospheric humidity levels

What factors affect the shape of the hydrograph?

• Annual rainfall intensity

• Soil pH variations

• Drainage area size

• Watershed characteristics

What is one use of the peak rate of runoff?

• Determining soil moisture content

• Sizing drainage structures and water impoundments

• Calculating groundwater recharge rates

• Estimating evapotranspiration rates

What does the runoff coefficient indicate about a watershed?

• Rate of sedimentation

• Proportion of impervious surfaces

• Rate of evaporation

• Depth of groundwater