WSPC05429

• File Number: 8283.200
• Description: Colorado River Basin-Colorado River Computer Models-Colorado River Decision Support System-Ray
• State: CO
• Water Division: 5
• Date: 1/1/1996
• Author: CADSWES
• Title: South Platte Water Rights Management System-Programmers Manual
• Water Supply Pro - Doc Type: Report/Study

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7

Description

reach

nodeJecord

using an expensive algorithm and stored in the in-memory graph. It is much faster to
use the stored information than to derive this list every time it is needed.

In addition, the in-memory graph contains infonnation not available in the database.
For example, upstream-downstream relationships are not represented in the database,
yet operations requiring this information are simple to perform using the in-memory
network graph. Determining the current call at a diversion structure requires knowing
the call structure in place on the river, as well as upstream-downstream spatial rela~
tionships between structures. The current call at a structure could not be determined
from the contents of the database alone, but by accessing both the database and the
spatial ArclInfo data. However, on-demand calculations using both of these sources
would be far too expensive.

The in-memory network graph is bupt from three primary components: reaches,
nodes, and node_link-pairs. A reach is a segment of the river system, corre-
sponding to a single arc in the Arc/Info stream network coverage. Nodes define the
ends of reaches, and are possible locations for confluences, stream gauges, or diver-
sion structures. Node_link_pairs are the structures that link the nodes and
reaches together to form a graph.

typedef struct {
(various members for graphic display)
lag_lass_record *lag_Ioss~record;
double length;
reach;

Where:

. lag_lass_record: A pointer to a lag_loss_record for a physical reach to
which this reach record refers.

. length: The length of the reach in meters.

The reach structure corresponds to a segment of the river as defined by a single arc in
the ArclInfo stream network coverage. Besides containing several numbers for
graphic display (of the current call structure), this structure contains a pointer to
lag_lass_record containing information about this reach.

typedef struct node_rec_struct{
short node_id;
short type;
Boolean visited;
double current_call;
double previous_call;
node_l ink_pair *connected_upstream;
node_l ink_pair *connected_downstrearn;
Boolean is_confluence;
node_type_description *description;
node_location location;
struct node rec struct *next;
} node_record;