X hits on this document

PDF document

Parameter Sensitivity in Hydrologic Modeling - page 109 / 163

356 views

0 shares

0 downloads

0 comments

109 / 163

Analytical calculation of the gradient involves plugging in each of the parameters derived from each level of parameter extraction into the SCS lag equation, shown in Equation 5.4, while holding the other parameters constant.

tlag (min) =

Lw

C N 9 1 0 0 0 7 . 0 8 31.67 . 0 s

Equation 5.4

In Equation 5.4, Lw is longest flow path in units of feet, and slope is expressed as a percentage. Curve number is symbolized by CN, and tlag is the lag

time in minutes.

Table 5.5

These numbers are the mean

outlines the base values calculated

values used for these calculations. for Area 2, as shown previously in

Table 5.2 and Table 5.4.

Table 5.5: Parameter Base Values

Parameter Base

Value

LFP

3.12 Miles

Slope

1.45 %

CN

89

5.2.1.1 Longest Flow Path

To evaluate changes in SCS lag time that result from changes in the longest flow path, the curve number and average slope were held constant while

99

Document info
Document views356
Page views356
Page last viewedSun Dec 04 02:40:51 UTC 2016
Pages163
Paragraphs3546
Words25756

Comments