Multi-scale basemaps can be used for both printed maps or to create the many zoom levels required for a Web mapping application. Multi-scale basemaps are typically created by deriving small scale map products from a large scale database.
Esri’s initiatives include generalization tools and map templates. Generalization tools help in the creation of smaller scale levels of detail and map templates that provide examples of finished multi-scale basemaps. Map templates both demonstrate best practices for setting up a multi-scale basemap, and also provide a starting point for those who would like to symbolize and cache their data in a manner that matches ArcGIS Online or other templates within their industry.
Generalization tools help automate the processes that map makers use to select, displace, simplify and clarify geographic features when deriving small scale maps and data from large scale data. Large scale maps cover a small area and provide more detail, whereas small scale maps cover a larger area and are rendered with less detail.
Generalization requires geoprocessing algorithms and advanced problem solving that mimic the selection and clarification process that a map maker intuitively uses when compiling a map at a smaller scale. Traditional generalization tools focused on single feature geometry a layer at a time, not taking into account the size and shape of the feature when rendered with symbology. The newest generation of tools for generalization takes into account the relationships of multiple features between multiple layers, as well as the size of symbology at target scales. The following tools can be applied to the most common generalization tasks and are currently focused on transportation and building features:
Thin Road Network
Reduces the number of visible roads while retaining connectivity and the relative pattern and density.
Collapse Road Details
Removes details that interrupt the flow of the road network, such as traffic circles, while maintaining road connectivity.
Merge Divided Roads
Creates a single road features from parallel roads or lanes.
Resolve Road Conflicts
Separates roads which coalesce at smaller scales.
Uses displacement polygons from the Resolve Road Conflicts tool to maintain the relationship of features adjacent to displaced roads.
Resolve Building Conflicts
Separates, rotates, and thins point, line and polygon building features while retaining the relative density and pattern.
Delineate Built-up Areas
Creates built-up area polygons from densely grouped point and polygon buildings.
These tools can all be used within Model Builder or Python scripts to automate complex generalization workflows. The latest development efforts have focused on enabling these tools to work with partitions in order to process extremely large data sets in order to support the creation of multi-scale maps for both print and Web output.
The ArcGIS Map Templates are available on the ESRI Resource Center. Map templates provide real examples and demonstrate best practices for creating multi-scale base maps for use on the Web, within mobile applications, and for printed map products. These map templates are useful examples of professional maps. You can use the cartography and data designs in these templates with your organization’s geographic information to generate your own professional maps. These will help you to effectively deploy a broad array of applications, convey scientific analysis and research, and support daily operations.
There are templates for topographic maps, street maps, geologic maps, water/waste water, local government infrastructure, with more templates being added.