trace analysis network modeling

Instructions for Use

Create and set the flow direction for trace analysis.

When creating a flow direction field, first specify the source and sink points in the trace network, and store the source-sink information in a field. The flow direction field is calculated based on the source-sink information field. Additionally, a river level field can be created to store river levels.

Operation Steps

  1. In the "Environment Settings" window, click the Create Flow Direction drop-down button -> Trace Analysis Network Modeling button.
  2. In the "Trace Analysis Network Modeling" dialog box, select the network dataset for which to create the flow direction for trace analysis, and set the node ID field, edge ID field, start node ID, and end node ID for that network dataset.
  3. Select the "Create Flow Direction" checkbox, set the name of the node type field and the flow direction field. The default generated node type field is NodeType, used to store the imported node type. A value of 0 indicates a common node; 1 indicates a source point; 2 indicates a sink point.
  4. If river level creation is needed, select the "Create Level" checkbox and name the river level field.
  5. Set whether loops are valid. This parameter is only valid for networks with level creation. Selecting the "Loop Valid" checkbox means that during trace analysis, loops are considered, and the resulting path may contain loops; otherwise, routes with loops are not considered during analysis.
  6. In the "Source-Sink Settings" area on the right, click the "Import" button to open the "Import Node" dialog box. In this dialog box, set parameters related to importing source and sink points.
    • Import: Import source and sink point data and set parameters.

      Datasource: The datasource containing the source and sink points to import.

      Dataset: The dataset containing the source and sink point data.

      Node Type Field: If the source and sink point types are already set and stored in a field, select this field to import the node type information along with the points.

      Filter: Import nodes that satisfy the filter. Enter the expression directly or click the browse button to define the filter using the "SQL Expression" dialog box. For using SQL Expression, refer to the SQL Expression page.

      Import by Associated Node: Selecting this checkbox means using an associated field to import nodes. In cases where network analysis stations need to be used as network nodes, users can select a field from the point dataset as the associated field during import. This field is linked to the network node ID field (internal association field) to complete node import.

      Node ID Field: Consistent with the node ID field in the "Environment Settings" dialog box. This parameter is only available when the "Import by Associated Node" checkbox is selected.

    • Export: Export the source and sink point information and save it as a point dataset.

      Datasource: The datasource to save the exported points.

      Dataset: The name of the point dataset to save the exported data.

      Node Type Field: The name of the node type field after export.

      Node ID Field: The name of the node ID field after export.

    • Select All: Select all nodes in the source-sink settings area list.
    • Select Reverse: Invert the selection of nodes in the source-sink settings area list.
    • Delete: Delete the selected nodes in the source-sink settings area list.
    • United Value Settings: Perform united value settings for the currently selected nodes to modify their node type. Click the "United Value Settings" button to open the "United Value Settings" dialog box, where you can change the node type to source, sink, or common node using the drop-down arrow.
  7. After setting the parameters, click the "OK" button to complete the trace analysis network modeling operation.

Notes

If the current network dataset has only one subnetwork, it only supports calculating the flow direction with one source and one sink. If the network dataset has multiple disconnected subnetworks, it supports calculating the flow direction with multiple sources and multiple sinks.