The cross-sectional data section begins with a record containing the only the keyword "BEGIN CROSS-SECTIONS:" and ends with a record containing the only the keyword "END CROSS-SECTIONS:". A cross section is represented by multi-record object beginning with a record containing only the keyword "CROSS-SECTION:" and ending with a record containing only the keyword "END:."
A cross-sectional object must include records identifying the Stream ID, Reach ID, and Station value of the cross-section, a 2D cut line, and a series of 3D locations on the cross section. Stationing is given in miles for data sets with plane units of feet and in kilometers for data sets with plane units of meters. A cut line is composed of the label "CUT LINE:" followed by an array of 2D locations. A cross-sectional polyline consists of the label "SURFACE LINE:" plus 3D coordinates written as comma-delimited X, Y, Z real-number triples, one triple to a line. A summary of record that may be used in the River Network section are provided in Table B-3.
Table B-3. Cross-sectional data section options for the spatial data format.

Keyword

Value Type

Value

CROSS-SECTION:

None

Marks beginning of Cross Section object.

END:

None

Marks end of a Cross Section object.

 

 

 

The following records are required for a Cross Section object.

 

 

STREAM ID:

String

Identifier for the River on which the cross section resides.

REACH ID:

String

Identifier for the Reach on which the cross section resides.

STATION:

Float

Relative position of the cross section on the river reach.

CUT LINE:

Location array

Array elements contain planar coordinates of cross section strike line.

SURFACE LINE:

Location array

Array elements contain 3D coordinates of cross section.

 

 

 

The following records are optional for a Cross Section object.

 

 

NODE NAME:

String

Description of cross section.

BANK POSITIONS:

Float

Fraction of length along cut line where main channel bank stations are located.(Left, Right)

REACH LENGTHS:

Float

Distance along left overbank, main channel and right overbank flow paths to next cross section downstream.(Left, Channel, Right)

N VALUES:

Float

Manning's n values expressed as a fraction along cut line to start of n value.(fraction, n value)

LEVEE POSITIONS:

String, Float

Levee positions expressed as a fraction along cut line to position with elevation.(ID, fraction, elevation)

INEFFECTIVE POSITIONS:

String, Float

Ineffective flow areas expressed as a fraction along cut line to beginning and end positions with trigger elevation.(ID, begin fraction, end fraction, elevation)

BLOCKED POSTITIONS:

Float

Blocked flow areas expressed as a fraction along cut line to beginning and end positions with trigger elevation.(ID, begin fraction, end fraction, elevation)

WATER ELEVATION:

String array

Water surface profile names exported from HEC-RAS. RAS GIS Export File only.