Remove features for multiscale mapping

Select, Eliminate, Refine,Filter (e.g., definition query on size), Prune (new USGS hydro tools), Thin (new ArcGIS road thinning tools)

Concept is not treated systematically in literature or tools

Be systematic about use of elimination through scale (39%!)

Database-driven cartography needs importance attributes for all feature types to drive elimination of labels and features

ScaleMaster.org – multiscale design decisions

Populated place labels – case study

Incorp. GNIS pt CDP MCD County

Dynamic labels in ArcGIS, no annotation

Incorp. GNIS pt CDP MCD County

Incorp. GNIS pt CDP MCD County

Incorp. GNIS pt CDP MCD County

Incorp. GNIS pt CDP MCD County

Elimination matters!

Label sizes by population and map scale

Label pattern for incorporated places (C5) only

Details…See Brewer presentation from ICA Commission meeting on Generalisation and

Multiple Representation last weekaci.ign.fr

Hydrography case study

Hydrography data for smaller scale

‘Display’ and ‘Geometry’ changes– Pruning (remove in database) C-– Simplification Gs– Collapse (centerline replaces river area) Gc– Selection on size (remove in database or remove symbol) C-• estimated upstream drainage area (UDA)• polygon area

– Reclassify (categories, taper by UDA) Cc

Also, symbol lightness, width, label size, label removal… Sc Sz La L-

Brewer and Buttenfield, 2010, Geoinformatica

Hydro change through scale

• Fuller map design context (captures from ArcGIS screen)

• Compare geometry/display change to display only solutions

• 11 slides, with toggling through versions at each scale

24K hydro data(OK at 36K)

24K hydro data(not suited to 72K)

50-200K LoD(OK at 72K)

50-200K LoD(OK at 144K)

50-200K LoD (not suited to 289K)

Geometry solution

200-500K LoD(OK at 289K)

50-200K LoD(display-only solution

at 288K)

500K-1M LoD (OK at 578K)

Elimination decisions in ScaleMaster

Remove features for multiscale mapping

Of 94 changes in draft ScaleMaster:30% label changes (including removing labels)26% symbol changes14% geometry changes (not yet applied to all themes)31% content changes

Content and label removal are 39% of design decisions in this draft multiscale mapping (20K to 1M)

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