Point Flow Analysis Software for the Lower South Platte River

• Description: User Guide: Point Flow Module & Querying & Charting Module
• State: CO
• Basin: South Platte
• Water Division: 1
• Date: 12/1/1994
• Author: Northern Colorado Water Conservancy District
• Title: User Guide for the Point Flow Analysis Software for the Lower South Platte River Kersey to Julesburg
• Water Supply Pro - Doc Type: Report/Study

point flow calculations.). A table consists of multiple records. The records, in turn, contain
multiple fields. Records can be compared to horizontal 'rows' in a spreadsheet environment,
whereas fields are similar to vertical 'columns' in a spreadsheet environment. The width of
each field, as well as the type of data to be stored in the field (numeric, character, date), is
defined upon creating a table. A computer file which corresponds to a table (database) can be
recognized by a .dbf extension on the file name.
Figure 1 provides a better understanding of some of the terms listed above.
u
River
knowing Stream Diverting canal
or Drainage Ditch or Ditch
River Flow Diroct y
Below/Above St1IIdUR8
b
Channel I V * * * * * *
V V t • * * * *
V I V * * * * V I
Node Gain/Loss
Node Gdn/LAea
Node Gain/Loss Node
A
B
C D
River
River
River
- - - - - - Subreach -------
Subreach _______
:- - - - - -- Subreach ------- i
r
A -B
i
B-C
C-D
i
i
------------------
- - - - -- River Reach ----------------- - - - - --
Figure 1 - Schematic of Point Flow Software 'river' terminology.
Depicted in Figure 1 is a river reach defined by Gauges I and II (points of known river flow).
Through the course of the river reach an inflow to and a diversion from the river occurs (at
Nodes B and C, respectively). This partitions the river reach into three subreaches (A -B, B -C,
and C -D). Bi- directional arrows indicate the gains/losses which are calculated for each subreach.
The horizontal line representing the river reach in Figure 1 is encircled at locations in which river
flows are calculated (above and below each structure).
In the following text the adjective 'river' is often neglected when using words such as channel,
flow, reach, and subreach. Unless explicitly noted otherwise, such words are in reference to the
main stem river.
The point flow computations are based on elementary volume balance theory and are performed
in a two step fashion. The first step entails creating a conservation equation (volume) within a
defined reach so that total reach gain can be calculated, and subsequently allocated, over the
length of the reach. The second step of the point flow calculations utilizes the calculated subreach
gains to compute the flows above and below each structure. This two step process and the
associated assumptions are outlined in detail below.
5 ptflguid.wpd