2.0

Table Of Contents
Outputting Data in the HEC-2 Format
609
HEC-2 Data Structure
Field Variable Value Description
0IA X1
Record identification numbers
1 SECNO ++
Cross section identification number
-
Start new tributary backwater at this cross section
2 NUMST 0
Previous cross section is repeated for current section; GR records
are not entered for this cross section
++
Total number of stations on the following GR records
3 STCHL 0 NUMST(X1.2) is 0
++ The station of the left bank of the channel; must be equal to one
of the STA(N) on next GR records
4 STCHR 0
NUMST(X1.2) is 0
++
The station of the right bank of the channel; must be equal to one
of the STA(N) on GR records and equal to or greater than STCHL
5XLOBL++
Length of left overbank reach between current cross section and
next downstream cross section; Zero for first cross section if IDIR =
0
6 XLOBR ++
Length of right overbank reach between current cross section and
next downstream cross section; zero for first cross section IDIR = 0
7 XLCH ++ Length of channel reach between current cross section and next
downstream cross section; zero for first cross section if IDIR = 0
8 PXSECR 0
Cross section stations do not change by the factor PXSECR.
++
Factor to modify the horizontal dimensions of a cross section. The
distance between adjacent GR stations (STA) are multiplied by this
factor to expand or narrow a cross section. The STA of the first GR
point remains the same. The factor can apply to a repeated cross
section or a current one. A factor of 1.1 increases the horizontal
distance between the GR stations by ten percent. (See X2.9 for
station adjustment to BT data.) This factor adjusts data from X3.
9 PSXECE 0
Cross section elevations do not change.
+ or -
Constant to be added (+ or -) to GR elevation data (either
previous or current); This factor also modifies sediment elevation
data (X3.2) input at current cross section; (See X2.7 for elevation
change to BT data); Does not adjust X4 records
10 IPLOT 0
Current cross section does not plot unless all cross sections were
requested by J2 record.
1 Plot current cross section using all points
10 Plot current cross section using only those points up to the water
surface elevation