This document discusses how water surface profiles within culverts are classified in two ways: 1) Hydraulic Slope, which is based on the culvert bottom slope and the relationship between critical depth and normal depth, and 2) Hydraulic Curve, which describes the shape of the water surface profile based on the Hydraulic Slope classification and the actual flow depth relative to critical and normal depths. There are five Hydraulic Slope classifications - Adverse, Horizontal, Critical, Mild, and Steep - which can change as flows increase. The three Hydraulic Curve classifications - Type 1, 2, and 3 - indicate whether flow is subcritical or supercritical.

1. PREPARED BY:-
13BCL045
13BCL046
13BCL047
13BCL048

2. CLASSIFICATION OF WATER SURFACE PROFILES
The water surface profile within a culvert can be classified
two different ways:
1. Hydraulic Slope, which is based on the slope of the
culvert bottom and
2. Hydraulic Curve, which is based on the relationship of
the water depth relative to critical depth and normal depth.
FishXing uses these classifications to determine the
appropriate inlet and outlet boundary conditions.

3. HYDRAULLIC SLOPE CLASSIFICATIONS
The Hydraulic Slope of a culvert at a specific flow classifies
the hydraulic regime and defines the type of solution
generated from the Gradually Varied Flow calculations.
Hydraulic Slope is determined from:
1. The culvert bottom slope (So) and
2. The relationship between critical depth (yc) and
normal depth (yn) at a specific flow.

4. There are five slope classifications:
· Adverse (A) if So < 0 (slope is positive in the
downstream direction)
· Horizontal (H) if So = 0
· Critical (C) if Yo = yc
· Mild (M) if So> 0 and yn > yc
· Steep (S) if So > 0 and yn < yc
For culverts with slopes > 0, the slope classifications change
as flows change. It is not uncommon for a culvert to
switch from being Mild Slope to Steep Slope as flows
increase.

5. HYDRAULIC CURVE CLASSIFICATIONS
Hydraulic Curve classifications are used to describe the
shape of the water surface profile at a specific flow. The
curves are based on the Hydraulic Slope (A, H, C, M, or S)
and the relative position of the actual flow depth to normal
and critical depth as designated by the numbers 1, 2, and
3.
· Type 1 curve: Depth is greater than yc and yn, flow is
subcritical
· Type 2 curve: Depth is between ycand yn, flow can be
either subcritical or supercritical
· Type 3 curve: Depth is less than both ycand yn, flow is
supercritical.

7. THANKS