ARCSDE GEODATABASE
GeoFIRM is a database-centric platform in which both cartographic and database products are produced directly from the database. The GeoFIRM environment takes advantage of a number of advanced capabilities of ArcGIS/ArcSDE to make this possible. In some cases, we have tailored these capabilities to fit the unique needs of supporting GeoFIRM activities. Some of the key features are:
Efficiency: Feature-linked Annotation
Our GeoFIRM environment makes extensive use of feature-linked annotation during the creation of the cartographic DFIRM product. We annotate the map from the database, and changes to the database are automatically reflected in the map because of the feature-linking. An excellent example of this is the manner in which the GeoFIRM environment handles cross-section annotation. GeoFIRM use a DFIRM-compliant "S_XS" feature class naming convention for cross-sections; this feature class stores the cross section letter in an attribute field. If for any reason this value is updated, the update is automatically reflected in the feature-linked cross-section hexagon that is associated with the cross-section line. Most of our map annotation is placed and managed in this fashion (e.g. BFEs, latitude longitude coordinates, transportation annotation, benchmarks, etc.) Furthermore, we have created annotation subclasses to handle text for different scale panels. These subclasses contain properties that allow the annotation to appear at the proper size for a given panel. A significant advantage of feature-linked annotation is that it enforces the quality of the cartographic product; a change to the database is always reflected in the map.
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Consistency: Attribute Domains
The GeoFIRM environment makes extensive use of attribute domains (lists of valid values for attribute fields). In addition to the DFIRM-standard domains, we have also created a number of custom domains to further enforce quality and provide a managed workflow. One such example is that water names are presented as a domain when populating the relevant spatial layers (cross-sections, water lines, general structures, etc.) This means that the same drop-down list is presented whenever filling out the attribute value for a feature that has a water name, ensuring consistency and quality throughout the database.
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Quality: Topological Rules
DFIRM databases have specific requirements for capturing spatial data; for example, flood hazard lines and flood hazard area boundaries must be coincident. These types of relationships are enforced by topological rules in the GeoFIRM database. These rules are used to flag and correct topological errors, ensuring a spatially correct end-product. GeoFIRM users also employ topological editing tools to edit spatial data layers that share topological relationships. Use of these specialized editing tools ensures the topological rules are honored.
