For each shapefile selected, four files with the following extensions: SHP, SHX, DBF, and PRJ are actually required. In addition, because shapefiles must be segregated by shape type, a minimum of three shapefiles for Point, Line and Polygon types is needed if the shapefiles utilize the TYPE column in the DBF file for drawing attributes. For shapefiles that do not use the TYPE extension, a shapefile set is required for each drawing attribute type.
Some shapefiles are designed as layers, where a shapefile can represent all the rivers within a large area while another shapefile could be used for all the basin outlines. However, many shapefile sets are aligned with a specific project or basin. For an entity that was project aligned, it would not be unusual to need sixty or more files to describe all the various attributes required. A project consisting of a single Point, Line, and Polygon would require twelve shapefile components to define it.
HEC-MetVue supports the direct use of ZIP files to help manage this problem. Several shapefile sets can be placed into a ZIP file, and just like specifying an individual shapefile, a ZIP file can be specified. When a ZIP file is specified it is unzipped before use. ZIP files can have a hierarchical structure similar to a computer file system with many levels of subdirectories. HEC-MetVue will not search ZIP file subdirectories for shapefile. Only the shapefiles that reside in the ZIP file root will be used.