Shapefiles 

Definition

ArcView GIS software files from ESRI that contain digital map material of areas or polygons (that is, shapes). Shapefiles define the geometry and attributes of static geo-characteristics. Note that shapefiles have to be available in the format of the World Geodetic System 1984 (WGS 84). For more information on the World Geodetic System WGS 84, see www.wgs84.com.

Use

Shapefiles serve as a basis for displaying BW data on maps.

Structure

Format

The format of ArcView shapefiles uses the following files with special file enhancements:

.dbf – dBase file that saves the attributes or values of the characteristic

.shp – saves the current geometry of the characteristic

.shx – saves an index for the geometry

These three files are saved for each static geo-characteristic in the Business Document Service (BDS) and loaded to the local computer from BDS when you use BEx Map.

Shapefile Data from the ESRI BW Mapping Data CD

The map data from the ESRI BW mapping data CD was selected as the basic reference data level to provide you with a detailed map display and also with thematic mapping material on the levels of world maps, continents and individual countries. The reference data levels involve country boundaries, state boundaries, towns, streets, railways, lakes and rivers. The mapping data is subdivided into data for 21 separate maps.

There is mapping data for:

·        a world map

·        seven maps on continent level, for example, Asia, Europe, Africa, North America, and South America.

·        13 maps on country level: The data for countries may vary. Most of the country boundaries are from 1960-1988; some countries have been updated to their position in 1995.

The names of the shapefiles on the ESRI BW mapping data CD follow a three-part naming convention.

·        The first part consists of an abbreviation of the thematic content of the shapefile, for example, cntry stands for a shape file with country boundaries.

·        The second part of the name indicates the level of detail. There are, for example, three shapefiles with country boundary information at different levels of detail. The least detailed shapefile begins with cntry1, whereas the most detailed shapefile begins with cntry3.

·        The third part of the name indicates the version number of the shapefile, based on the last two digits of the year beginning with the year 2000. Therefore, the full name of the shapefile with the most detailed country boundary information is cntry300.

All shapefiles on the ESRI BW mapping data CD already contain the SAPBWKEY column. For countries, the two-figure SAP country key is entered in the SAPBWKEY column.

The file Readme.txt on the ESRI BW mapping data CD contains further, detailed information on the delivered shapefiles, the file name conventions used, the mapping data descriptions and specifications, data sources, and how up-to-date the data is.

Integration

At run time, the shapefiles are downloaded from the BW to the IGS (Internet Graphic Server). The files are copied into the /data/shapefiles index. If a specific shapefile is already in this directory, it is not copied again. If the shapefile has been changed in the Business Document Service (BDS) in the meantime, the latest version is copied automatically into the local directory.

Depending on the level of detail, shapefiles can be quite large. The shapefile cntry200.shp with the country boundaries for the entire world is around 2.2 megabytes. For small organizational units, such as federal states, the geometric information is saved in several shapefiles. That is, you can assign a characteristic to several shapefiles (for example, states in Germany and in France.).