University of Central Florida
Civil and Environmental Engineering
CWR4101 Hydrology Laboratory 5D
Estimation of Infiltration
OBJECTIVE
-
A. To understand the use of a spreadsheet in Hydrology
-
B. To effectively estimate infiltration and excess
EQUIPMENT
Computer with spreadsheet software.
PROCEDURE
-
Using the NRCS Curve Number Method calculate the excess hydrograph for
a residential watershed with 30% impervious area and 70% pervious area
if the pervious area has a good sod cover with scattered trees. Use an
NRCS Type II storm that has a return period of 5 years, a duration of 12
hours and occurs in Orange County, Florida. Assume a hydrologic soil class
of D. Use a spreadsheet to generate solutions using:
-
the composite curve number method;
-
separate routing.
-
Also, estimate the Horton Infiltration Parameters assuming the NRCS infiltration
is representative of the watershed. Use the infiltration from the separate
routing.
Cum. P
(non-dim)
0.000
0.002
0.005
0.008
0.011
0.014
0.017
0.020
0.023
0.026
0.029
0.032
0.035
0.038
0.041
0.044
0.048
0.052
0.056
0.060
0.064
0.068
0.072
0.076
0.080
0.085
0.090
0.095
0.100
0.105
0.110
0.115
0.120
0.126
0.133
0.140
0.147
0.155
0.163
0.172
0.181
0.191
0.203
0.218
0.236
0.257
0.283
0.387
0.663
0.707
0.735
0.758
0.776
0.791
0.804
0.815
0.825
0.834
0.842
0.849
0.856
0.863
0.869
0.875
0.881
0.887
0.893
0.898
0.903
0.908
0.913
0.918
0.922
0.926
0.930
0.934
0.938
0.942
0.946
0.950
0.953
0.956
0.959
0.962
0.965
0.968
0.971
0.974
0.977
0.980
0.983
0.986
0.989
0.992
0.995
0.998
1.000
OUTPUT Your Output should contain the following;
- A spreadsheet with the solution to the CCN routing
- A spreadsheet with the solution to the separate routing
- A plot of infiltration rate vs. time for both routings on the same graph
- A plot of cummulative infiltration vs. time for both routings on the same
graph
- The estimates for fo, fc, and K
- A plot of infiltration rate vs. time for both separate routing and Horton's
equation on the same graph