Technical data

Chapter 8 AutoCAD Map and AutoCAD Land Development Desktop
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Node Topologies
Node topologies are made up of point nodes. You can create a node
topology for borehole data, and then perform a thematic query that
shows the core materials at a depth of 10 feet, for example.
Network Topologies
Network topologies are made up of lines and arcs that are associated
with each other, such as a street map or stream network.
For example, you can create a network topology out of all the roads in
a city. A network topology is composed of nodes (points where three
or more lines intersect) and links (the lines that link the nodes
together). For example, you can create a network topology of sanitary
sewer pipes and control the direction of flow. Likewise, you can define
which roads in a road network topology are one-way, have congested
traffic, and so on. You can then use this information to trace the
shortest route to a destination.
Polygon Topologies
Polygon topologies are made up of lines and arcs that define enclosed
areas, where each area forms a polygon. For example, you can define
the areas within closed polylines, such as parcels, as a polygon
topology. Any common boundaries between polygons are shared
between both polygons. When you create a polygon topology,
centroids are created for the polygons. The centroids store the object
data for the polygons.
Key Concepts
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You can perform a path trace or flood trace on network topologies.
A path trace can show the shortest route from one point on a map
to another. A flood trace traces out from a point in all directions, to
a maximum specified distance. For example, you can use a flood
trace to show all the parcels within a 500 meter radius of a
proposed community well location.
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Each object in your drawing can be in more than one topology.
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You can create buffers around objects in topologies. For example,
you can create buffers around point objects or streams. When you
create buffers, the end result is a polygon, because the buffer is a
polyline that surrounds an enclosed area.