My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
FLOOD03276
CWCB
>
Floodplain Documents
>
Backfile
>
3001-4000
>
FLOOD03276
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
1/25/2010 6:26:48 PM
Creation date
10/4/2006 11:37:18 PM
Metadata
Fields
Template:
Floodplain Documents
County
Statewide
Basin
Statewide
Title
Hydrologic Engineering Methods for Water Resources Development Volume 4
Date
10/1/1973
Prepared For
US
Prepared By
US Army Corps of Engineers
Floodplain - Doc Type
Educational/Technical/Reference Information
There are no annotations on this page.
Document management portal powered by Laserfiche WebLink 9 © 1998-2015
Laserfiche.
All rights reserved.
/
74
PDF
Print
Pages to print
Enter page numbers and/or page ranges separated by commas. For example, 1,3,5-12.
After downloading, print the document using a PDF reader (e.g. Adobe Reader).
Show annotations
View images
View plain text
<br />sampling errors usually result because of the preponderance of stations <br /> <br /> <br />at low elevation. Their average usually represents less precipitation <br /> <br /> <br />than occurs on the basin as a whole. In such regions, an isohyetal map <br /> <br /> <br />can still be employed to advantage if the effect of topography is taken <br /> <br />into consideration in locating isohyetal lines. <br /> <br /> <br />Where average annual precipitation varies appreciably over a basin <br /> <br /> <br />and storm preeipitation usually reflects such variation (as in mountainous <br /> <br /> <br />regions), an adjustment by use of long-term averages can be made. The <br /> <br /> <br />average storm precipitation for a basin is determined by multiplying the <br /> <br /> <br />weighted storm precipitation ,at each station by the ratio of the average <br /> <br /> <br />annual precipitation of the basin to the weighted average annual precipi- <br /> <br /> <br />tation at that station. The long-term average for the basin is determined <br /> <br /> <br />by one of the methods previously discussed, using all stations having <br /> <br />appreciable record. Where average annual precipitation is not a goo~ indi- <br /> <br /> <br />cator of the areal variation of storm precipitation, average precipitation <br /> <br /> <br />for the rainy season, average storm precipitation, or storm precipitation <br />. <br /> <br />amounts exceeded with a specified frequency (such as once in 10 years) can <br /> <br /> <br />be used for this adjustment. The principal advantage of this type of adjust- <br /> <br /> <br />ment is that some information on normal area patterns is obtained from stations <br /> <br />that do not have records for a particular storm. <br /> <br /> <br />Computer program number 723-Gl-L2260, "Basin Rainfall and Snowmelt <br /> <br /> <br />Computation," described in Appendix 2, is designed to accept preCipitation <br /> <br /> <br />gage rainfall data for a specific storm period and time interval for an en- <br /> <br /> <br />tire region, and to compute basin-mean values for any number of basins in <br /> <br /> <br />the region with output time intervals that are specified multiples or <br /> <br /> <br />fractions of the input time interval. These routines are also incorporated <br /> <br /> <br />into computer program, HEC-l, "Flood Hydrograph Package, n which is described <br /> <br /> <br />in Volume 1 of this report. <br /> <br />2-07 <br />
The URL can be used to link to this page
Your browser does not support the video tag.