[data models] A small, narrow, polygon feature that appears along the borders of polygons following the overlay of two or more geographic datasets. Sliver polygons may indicate topology problems with the source polygon features, or they may be a legitimate result of the overlay.
A small areal feature commonly occurring along the borders of polygons following the overlay of two or more coverages.
Tiny sliver polygons or gaps between polygons often result from creating new polygons without using snapping or editing shared boundaries without a topology. Slivers and gaps keep your dataset from forming a continuous fabric and should be identified and fixed as appropriate.
Gap between two lines created erroneously by a scanner and its raster-vector software.
Refers to polygons formed when two adjacent polygons do not abut along a single common line resulting in the creation of a very thin polygon being present between the larger two.
slivers and gaps in the line work;
dead ends, e.g. also called dangling arcs, resulting from overshoots and undershoots in the line work; and
bow ties or weird polygons from inappropriate closing of connecting features.
~ polygons can also be created between features within the same map. Typically, map features are separately digitized. For example, the GIS (or CAD) operator will trace the boundary of each state with a digitizing tablet or mouse.
~s, the most common topological problem, are small polygons that occur when either shared boundaries are entered separately for contiguous polygons or when the features of two layers are overlaid but do not match precisely.
~ polygon - A extremely small polygon, usually of elongated shapes, that results from errors in data capture and overlay analysis when identical linear objects fail to register. It is also known as a spurious polygon.
6. What is ~ Polygon? Describe how to create ~ polygons and using what function to delete them.
7. Describe what are slope and aspect, how to measure them.
Note: please see Michael L. Hauschild's page for the last three parts.
A second potential source of error associated with the overlay process is error propagation. Error propagationWhen inaccuracies are present in the original input and overlay layers and are carried through to an output layer.
~ Polygon A relatively narrow feature commonly occuring along the borders of polygons following the overlay of two or more geographic data sets. Also occurs along map borders when two maps are joined, as a result of inaccuracies of the coordinates in either or both maps.
Needle Ice A form of periglacial ground ice that consists of groups ice ~s at or immediately below the ground surface. Needle ice is about a few centimeters long.
the small, invalid polygons are called spurious or ~ polygons and can be a major problem in polygon overlay
spurious polygons arise when two lines are overlaid which are actually slightly different versions of the same line ...
You should never attempt to digitize over existing edges, because it is likely you will be creating gaps or ~s. Auto-complete is part of the topology tools. To access the topology, right click on the mouse from the menu, select the Topology and dock the toolbar in the GUI.
~ p. 114 an artifact of polygon overlay; usually created by overlay of two sources with different accuracy, different sources or different interpretations. slope p.
See also: What is the meaning of Polygon, Information, Feature, GIS, Vector?