SMS:Importing Shapefiles: Difference between revisions
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===Direct Conversion of Shapefile Data to Coverages=== | ===Direct Conversion of Shapefile Data to Coverages=== | ||
The first is the traditional method which allows you to load a shapefile layer directly into a coverage. | The first is the traditional method which allows you to load a shapefile layer directly into a coverage. | ||
You can then map attribute fields of the shapefiles database (*.dbf) file to their pertinent SMS parameters . | You can then map attribute fields of the shapefiles database (*.dbf) file to their pertinent SMS parameters . | ||
===Using the GIS Module to Convert Shapefile Data to Coverages=== | ===Using the GIS Module to Convert Shapefile Data to Coverages=== | ||
When opening a shapefile in the GIS module using the '''Add Shapefile Data''' or '''Add Data''' commands SMS first reads the points/lines/polygons into a simple display list and does not try to "build" topology by connecting arcs at nodes, and eliminating shared edges of polygons as required when creating a coverage. This makes the display and selection of the polygons much easier and more efficient. You can then select only the polygons you wish to convert to a coverage and map them. In this way you will only be building topology for the selected polygons. | When opening a shapefile in the GIS module using the '''Add Shapefile Data''' or '''Add Data''' commands SMS first reads the points/lines/polygons into a simple display list and does not try to "build" topology by connecting arcs at nodes, and eliminating shared edges of polygons as required when creating a coverage. This makes the display and selection of the polygons much easier and more efficient. You can then select only the polygons you wish to convert to a coverage and map them. In this way you will only be building topology for the selected polygons. | ||
===Cleaning Imported Shapefile Data=== | ===Cleaning Imported Shapefile Data=== | ||
If you intend to use the data from the shape file in more than one session you should save it as a SMS map file after importing/mapping the first time. Further, after importing the shape files you may wish to consider the following: | If you intend to use the data from the shape file in more than one session you should save it as a SMS map file after importing/mapping the first time. Further, after importing the shape files you may wish to consider the following: | ||
# Clean the feature objects in order to snap nodes within a certain distance, intersect arcs, and eliminate dangling arcs. | # Clean the feature objects in order to snap nodes within a certain distance, intersect arcs, and eliminate dangling arcs. | ||
# Build Polygon so that SMS can define the appropriate conceptual model. After intersection of arcs, reordering of streams, etc. it is often necessary to rebuild the polygon topology so that the topologic structure is consistent. | # Build Polygon so that SMS can define the appropriate conceptual model. After intersection of arcs, reordering of streams, etc. it is often necessary to rebuild the polygon topology so that the topologic structure is consistent. | ||
==Related Topics== | ==Related Topics== | ||
Revision as of 16:06, 17 December 2013
ARC/INFO or ArcView® shape files provide an easy method to import GIS data into SMS. Unfortunately the shape file format is extremely redundant, meaning that points or lines that are shared by lines or polygons are multiply defined.
Therefore, in order for you to convert a shape file to a SMS coverage it may take up to several minutes (depending on size) to build the correct line or polygon topology. This was very problematic in previous versions because SMS often bogged down when reading moderately large files. This is one of the primary reasons that the new GIS module has been developed and with or without a license to ArcObjects shapefile data can now be managed better by SMS.
With the addition of the GIS module there are now two different ways to import shapefile data.
Direct Conversion of Shapefile Data to Coverages
The first is the traditional method which allows you to load a shapefile layer directly into a coverage.
You can then map attribute fields of the shapefiles database (*.dbf) file to their pertinent SMS parameters .
Using the GIS Module to Convert Shapefile Data to Coverages
When opening a shapefile in the GIS module using the Add Shapefile Data or Add Data commands SMS first reads the points/lines/polygons into a simple display list and does not try to "build" topology by connecting arcs at nodes, and eliminating shared edges of polygons as required when creating a coverage. This makes the display and selection of the polygons much easier and more efficient. You can then select only the polygons you wish to convert to a coverage and map them. In this way you will only be building topology for the selected polygons.
Cleaning Imported Shapefile Data
If you intend to use the data from the shape file in more than one session you should save it as a SMS map file after importing/mapping the first time. Further, after importing the shape files you may wish to consider the following:
- Clean the feature objects in order to snap nodes within a certain distance, intersect arcs, and eliminate dangling arcs.
- Build Polygon so that SMS can define the appropriate conceptual model. After intersection of arcs, reordering of streams, etc. it is often necessary to rebuild the polygon topology so that the topologic structure is consistent.
Related Topics
SMS – Surface-water Modeling System | ||
|---|---|---|
| Modules: | 1D Grid • Cartesian Grid • Curvilinear Grid • GIS • Map • Mesh • Particle • Quadtree • Raster • Scatter • UGrid |  |
| General Models: | 3D Structure • FVCOM • Generic • PTM | |
| Coastal Models: | ADCIRC • BOUSS-2D • CGWAVE • CMS-Flow • CMS-Wave • GenCade • STWAVE • WAM | |
| Riverine/Estuarine Models: | AdH • HEC-RAS • HYDRO AS-2D • RMA2 • RMA4 • SRH-2D • TUFLOW • TUFLOW FV | |
| Aquaveo • SMS Tutorials • SMS Workflows | ||
