Cartographic Design Advanced GIS Workshop April 28-29, 2012 Antioch University New England Chris Brehme Keene State College

Generalization Image from Paul Bolstad, GIS Fundamentals 3 rd Edition, 2010

Generalization

to represent the same data at different scales—e.g. Google Maps.

Terrain Modeling Begin with DEM – Sources (NH GRANIT, MassGIS, etc.; USGS Seamless Server) Run Hillshade – ‘Sun’ Angle and Azimuth can be determined from a website: Overlay with Aerial Imagery, set to semi-transparent to create a ‘Swiss Map’ style

Color Schemes: colorbrewer2.org

Matching Representation to Reality Geographic Phenomena Symbolization Space Federal Income Individual Income Alan MacEachren, How Maps Work, 1995

Dasymetric Mapping Method for ‘disaggregating’ data. Data collected at a coarse spatial aggregation are mapped more precisely using additional geographic data For example, census data collected in tracts is allocated to the built environment as it is identified.

Cheshire County Towns’ Population

Cheshire County Population Example Cheshire County population by Town Land Cover from USGS MRLC Extract Land Cover to Cheshire County and reclassify: – Each developed class remains the same – All other classes = 1

Cheshire County Population Example Convert LandCover raster to polygon, intersect with Town Pop. Each town has four multipart polygons: – One polygon for each development class Create ‘scores’ for each class type – Sparse development =.075 – Low development =.125 – Moderately developed =.25 – Intensely developed =.6

Cheshire County Population Example Use Field calculator to multiply the ‘score’ by the population of each town Population is now confined to the developed areas 1 dot = 1 person What are some of the flaws?

Map Series Time Series (same data represented over days, seasons, years) Thematic Series (different data layers covering the same location) Use Multiple Data Frames to create a Map Layout Use ‘Import Symbology’ to transfer the classes and colors from one legend to another – Legend classes must encompass the entire range of the data

Map Series