ENVIRONMENTAL SCIENCE
SOLUTION: Montclair State University Hydroclimatology Worksheet
SOLUTION: Montclair State University Hydroclimatology Worksheet.
EAES 531/332 – HYDROCLIMATOLOGY
Problem Set #3
(Due date: 04/19/2022)
Problem 1 (20 points): Philip’s Infiltration Equations
In a field measurement of infiltration over a pasture area using a ring infiltrometer, the
following recording was made: water level in the infiltrometer dropped 1.0 inch after the
first hour; dropped an additional 0.5 inch during the second hour. Note that infiltration
rate constantly changes with time, and evaporation is negligible. Assuming Philip’s
Equations apply, estimate the infiltration rate (in inches/hour) at the end of the third hour.
Problem 2 (20 points): Green-Ampt Infiltration Model
A rainstorm of constant intensity produces 1.6 cm of rainfall in two hours on a loam soil
(porosity η = 0.55, hydraulic conductivity K = 0.1 cm/hr, and wetting front soil suction
head ψ = 20 cm). The soil moisture content prior to the storm θi is 15%.
a) Compute the cumulative infiltration F and the infiltration rate f at t = 1 hour.
b) Calculate the cumulative infiltration F, infiltration rate f, and cumulative excess
rainfall (or surface runoff) at the end of the storm (i.e., at t = 2 hours)?
Problem 3 (20 points): SCS Method for Direct Runoff
a) Compute the runoff from a 7-in rainfall on a 1500-acre watershed that has
hydrologic soil groups that are 40 percent group A, 40 percent group B, and 20
percent group C interspersed throughout the watershed. The land use is 90 percent
residential area that is 30 percent impervious, and 10 percent paved roads with
curbs. Assume AMC II conditions.
b) What was the runoff for the same watershed and same rainfall before
development occurred? The land use prior to development was pasture and range
land in poor condition.
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attachment
Problem Set #3
(Due date: 04/19/2022)
Problem 1 (20 points): Philip’s Infiltration Equations
In a field measurement of infiltration over a pasture area using a ring infiltrometer, the
following recording was made: water level in the infiltrometer dropped 1.0 inch after the
first hour; dropped an additional 0.5 inch during the second hour. Note that infiltration
rate constantly changes with time, and evaporation is negligible. Assuming Philip’s
Equations apply, estimate the infiltration rate (in inches/hour) at the end of the third hour.
Problem 2 (20 points): Green-Ampt Infiltration Model
A rainstorm of constant intensity produces 1.6 cm of rainfall in two hours on a loam soil
(porosity η = 0.55, hydraulic conductivity K = 0.1 cm/hr, and wetting front soil suction
head ψ = 20 cm). The soil moisture content prior to the storm θi is 15%.
a) Compute the cumulative infiltration F and the infiltration rate f at t = 1 hour.
b) Calculate the cumulative infiltration F, infiltration rate f, and cumulative excess
rainfall (or surface runoff) at the end of the storm (i.e., at t = 2 hours)?
Problem 3 (20 points): SCS Method for Direct Runoff
a) Compute the runoff from a 7-in rainfall on a 1500-acre watershed that has
hydrologic soil groups that are 40 percent group A, 40 percent group B, and 20
percent group C interspersed throughout the watershed. The land use is 90 percent
residential area that is 30 percent impervious, and 10 percent paved roads with
curbs. Assume AMC II conditions.
b) What was the runoff for the same watershed and same rainfall before
development occurred? The land use prior to development was pasture and range
land in poor condition.
Purchase answer to see full
attachment
SOLUTION: Montclair State University Hydroclimatology Worksheet