eeos 381 - spatial databases and gis...

Lecture 8Display and Presentation

EEOS 381 - Spatial Databases and

GIS Applications

EEOS 381 - Spring 2015: Lecture 8 2

Maps (Cartography) - GIS as a powerful visualization tool– Fundamental to GIS projects– Most common form of GIS output product

• Paper and/or digital– Present results of analysis

>> COMMUNICATE– Follow standards– Art and science– Modern advances in

cartographymake it easy to produce good and bad maps

Importance of Effective Display

Here is where you finally get to show off the database you spent so much time creating!


Map Design Factors

Purpose– Why was the map produced?

RealityAvailable DataMap ScaleIntended Audience– Specialists? General Public?

Medium – hard or softcopy?– In a report?– On a wall?– On the Web?– Will map be static or interactive?

You may need to produce

several versions of a map, each

catered to a different

audience or for a different medium


Mapmaking Principles

Mapmaking is both an art and science– Conform to scientific standards and

conventions• Colors (blue water, green forest, etc.)• Fit in supporting elements around shape of

feature (legend, title, scale bar, logos, images, text, etc.)

• Placement of labels (upper-right of points as default; avoid overlapping other features)

• A bit of white space allows layout to “breathe”– But…be creative



Visual balance is important for all maps, regardless of purpose or audience– Visual harmony and symmetry among

elements– Proper sizing of components– Colors should not clash and should be

distinguishable; For more on color see:– http://personal.uncc.edu/lagaro/cwg/color/– http://www.personal.psu.edu/cab38/ColorBrewer/ColorBrewer_intro.html

– Figure-ground• Main features should stand out, not be lost among

reference layers (which should fade to background)


WORCESTERBERKSHIRE

ESSEX

MIDDLESEX

FRANKLIN

BRISTOL

HAMPDEN

PLYMOUTH

HAMPSHIRE

NORFOLK

BARNSTABLE

DUKES

SUFFOLK

NANTUCKET

Counties and Towns

LegendMGISDATA.TOWNS_ARC

MGISDATA.COUNTIES_POLY<Null>

BARNSTABLE

BERKSHIRE

BRISTOL

DUKES

ESSEX

FRANKLIN

HAMPDEN

HAMPSHIRE

MIDDLESEX

NANTUCKET

NORFOLK

PLYMOUTH

SUFFOLK

WORCESTER

0 56,000 112,00028,000 Meters

Ì

Poor balance among elements


WORCESTERBERKSHIRE

ESSEX

MIDDLESEX

FRANKLIN

BRISTOL

HAMPDEN

PLYMOUTH

HAMPSHIRE

NORFOLK

BARNSTABLE

DUKES

SUFFOLK

NANTUCKET

Comonwealth of Massachusetts

BARNSTABLE

BERKSHIRE

BRISTOL

DUKES

ESSEX

FRANKLIN

HAMPDEN

HAMPSHIRE

MIDDLESEX

NANTUCKET

NORFOLK

PLYMOUTH

SUFFOLK

WORCESTER

0 25 5012.5 Miles

²

Counties and Communities

Map produced by the Geographic Information Technologieslab at UMass-Boston, November 14, 2004.

Data from MassGIS.

Community Boundaries

Better Visual Balance


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n PRI

n PUB

0 2.5 51.25 Miles

²

SchoolsSouth of Boston


Data from MassGIS.

n PRI

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Poor use of figure-ground


Better use of figure-ground

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0 2.5 51.25 Miles

²

SchoolsSouth of Boston


Data from MassGIS.

n Private Schooln Public School

Map Area



A map should stand alone– Should present information without need for

extraneous explanation or support– Along with data area (map body) a layout should

include:• Good title• Legend (** with “English” layer and item names, not

names of files or fields **)• Scale (bar and or text)• Inset/locator map (use “Extent Rectangles” in ArcMap),

grid• North arrow• Tables, charts, graphs, images, text boxes• Date, source, author


Principal Layout Components

TitleLegend

Projection

Grid

Data Source

Inset map

Map Body

Author,Date

North Arrow

Scale



GIS maps typically avoid the fancy artwork of older-style maps–Should focus on message of the map

(data frame), without distractions–But, maps should not be boring – use

capabilities of software to create visually pleasing layouts

–Map vs. poster display


Limitations of Paper Maps

Fixed scaleFixed extentStatic viewFlat and hence limited for 3D visualizationPresents ‘complete’ world viewMap producer-centric


Two basic types of maps

1. General reference maps

– Basic geography of an area

– Base maps, road maps, topographic maps


Two basic types of maps

2. Thematic maps– Present selected

themes (land use, population)

– Use of shading and patterns• Choropleth

(shaded area) maps

• Dot density• Graduated

symbols (lines and points)


Attribute Representation

Use attributes to determine display characteristics (a.k.a. “Classification”)– Nominal

• Each category gets a different symbol• “Categories” in ArcMap Symbology tab

– Ordinal• Graduated colors, size, thickness• “Quantiles” – Graduated colors/symbols in ArcMap

– Interval/Ratio• Line width, point size, colors change continuously

based on range of values; dot density, bar charts inside polygons

• “Quantiles” – Proportional colors/symbols in ArcMap


Attribute Representation

Nominal

Ordinal (graduated points)

Interval/Ratio (proportional points)


Classification Schemes

Natural Breaks – based on natural groupings inherent in the dataEqual Interval – data divided into equal-sized ranges, based on set number of classesDefined Interval – user defines the interval, which determines number of classesQuantile – each class contains an equal number of featuresStandard Deviation – shows how much an attribute value varies from the meanManual – user defines class breaks manually

See textbook (chap. 12) and ArcGIS Help for details on these



Base the scheme on the data you’re usingLook at the distribution of values (view the histogram in ArcMap)It’s often difficultto distinguish more than7 classes

Histogram view in ArcMap



Data may be “normalized”:–Divide one numeric field by another

to minimize differences based on area (i.e. to show density) or number of features in each area

– If your data is in raw counts that are expressed in very large numbers, especially if polygon areas are of varying sizes



Raw data(population values in each

Census Block)

Normalized data(raw population values divided by

acres –> density map)



• Comparison of four choropleth classification schemes (from page 313 in textbook)- Different

schemes on same data may yield different display results


Classification Rules

Each class interval is unique– No data value can be in more than 1 category– Use 1-2, 3-4 or 1-2.9, 3-3.9 (not 1-2, 2-3, etc.)

No gaps should exist between class intervals– Even if values don’t exist (but may be overridden

with ArcMap’s “Use data values” checkbox)The number 0 (zero) is often a valid value– The absence of something can be as meaningful as

its presenceThe classification scheme should make sense– Should be consistent and use understandable

categories and intervals


Multivariate Mapping

Show 2 or more variables for comparative purposes

– Examples:• Rainfall vs.

malaria risk• Different

properties of soils• Income/race

compared to MCAS scores


Cartograms

Maps on which the geographic features are distorted (shape, area, distance, location) in the interests of a specific objective– To reveal patterns or promote legibility– Examples:

• The size of a geographical area is drawn proportionately to the value of the data it contains (Good example: election maps – see http://www-personal.umich.edu/~mejn/election/2008).

• Linear cartogram of subway system map.


Cartograms (cont.)

Real geometry of data Data as a cartogram


Cartograms (cont.)

Regional map of UK

Equal population cartogram transformation


Graphic Techniques

Manipulate symbols in the following ways to achieve diversity amongst symbols:– Size– Value– Hue– Saturation (chroma)– Orientation– Shape– Arrangement– Texture– Focus

See Figure 12.9 in textbook (Bertin's Graphic Primitives, at right) and by exploring individual symbols’ “Properties” dialogs in ArcMap

CMYK – Cyan, Magenta, Yellow, BlackRGB – Red, Green, BlueHSV – Hue, Saturation, Value


Displaying Rasters

Adjust contrast/brightness– Effects toolbar in ArcMap

Apply a stretch– Properties > Symbology tab in ArcMap

Choose bands for multispectral imagery– “True color” uses bands 1,2,3 for RGB channels– If near infrared available, use 4,1,2 (Symbology tab)

Choose how to Resample during display– Properties > Display tab in ArcMap

See examples and screenshots athttp://www.mass.gov/anf/docs/itd/services/massgis/displayoptions2005colororthos.pdf


2005 color ortho imagery shown with bands 4 (near infrared), 2, and 1

Displaying Rasters


Labeling

Text that identifies features on a map– Important for readability & communicationConsiderations:– Size

• can vary (even within one layer, depending on size of feature(s)

• Should not be too small or too large– Font style

• one style for one layer (color, font type and style)• a different style for each layer• don’t use too many different font families

– Great resource: http://www.typebrewer.org/


Labeling


Labeling

Considerations (cont.):–Placement on the map

• Typically in center of polygon, above or to right of line, to upper right of points

• Should not overlap other labels• Should not obscure features• Should be clear which feature is labeled

(can use leaders)• Not all labels may be placed – based

on scale, size, density of features, etc.


Examples of city points labeled based on their position relative to the coast

•Either all on land or in the water

Labeling


Matching label colors to feature colors

Change font color and size, but keep same typeface (Arial)

Labeling


LabelingConsiderations (cont.):– Orientation of the text

• Can curve to follow linear features (rivers, streets)

• Read left to right, top to bottom, depending of angle of line

• May be tilted (rotated) to fit inside a polygon

You can also S P A C E labels that cover large areas


Varying orientation and style (color, italics) while still using one typeface

Labeling


Labeling

Considerations (cont.):– You usually need to experiment a bit,

especially when you are labeling many features and many layers

– In ArcMap, labels may be dynamic (placed automatically) or placed manuallly (by user in exact desired location); label classes may be defined

– Labels may be converted to annotation(in map or geodatabase) or saved as part of layer file for reuse


Labeling

Considerations (cont.):– Can be time-consuming to get “just

right”– Label classes can help manage labels for

one layer– Can use ArcGIS Maplex extension for

advanced labeling– Can use Labeling toolbar – with “Label

Manager” in ArcMap


Labeling

Default vs. modified label properties

Default “Label Features” Modified Properties (with Maplex)


LabelingMassDOT Streets labeled with many “label classes” in ArcMap (and symbolized using Categories method on CLASS field)


Labels vs. Annotaion

*

Labels also may be manually placed with the Label tool from the Drawing toolbar.See http://gis.esri.com/library/userconf/egug2005/papers/annotation.pdf for more details.

*

Labeling

Also see http://www.maptext.com/


Layer FilesStore display properties and pointers to source data; allow cartographer to reuse symbology settings and enhance user experience– Right-click layer in ArcMap table of contents and select

“Save as layer file…” (.LYR file)– May store grouped layers & groups of grouped layers– Scale dependent data and labeling– Definition queries– Allow data and application developers to distribute

consistent presentation (an organization’s “legacy” or “look and feel”)

– Be aware of relative paths!! (See File > Document Properties > Data Source Options)


Layer and Map Packages

Save layers (LYRs) and map documents (MXDs) as “packages”– consolidate data into a single folder or

compressed file, to organize and share your data and maps with others.

See http://resources.arcgis.com/en/help/main/10.1/#/An_overview_of_the_Package_toolset/0017000000q6000000/


ArcPublisher/ArcReaderArcPublisher: Extension to ArcGIS that allows a map (all layers with their symbology, labels, queries, full layout, etc.) to be “published” as PMFArcReader: Free software to read PMFs– Similar in concept to Adobe PDF files read in free

Acrobat ReaderYou can package data with PMF or point to local, network, or Web data sources


GeoPDF

Products from TerraGo TechnologiesCreate maps in ArcMapView them as “real” maps in Adobe Reader– Access features and attributes– Turn layers on and off– Projections and coordinate systems

preserved– Measure length and area– Mark up the maps and export to shapefiles– See http://www.terragotech.com/products/terrago-

publisher/


Map Series

Collections of maps – often the same theme (or sets of themes), with same general design, but for different geographic extentsData-driven Pages in ArcMap for automation of map series, based on tiling scheme or indexESRI’s “Mapping andCharting Solutions”

See http://www.esri.com/software/arcgis/extensions/mapping-charting


Cartographic Representations

Introduced in ArcGIS 9.2Symbology “rules”/settings stored in GDB feature classes’ attributes tablesFacilitate and automate high-quality cartographic outputIncludes symbol offset, generalization, maskingOverrides allowedSee http://www.esri.com/news/arcnews/winter0506articles/putting-the-art.html



Example: Converting existing symbology



Line features in a feature class drawn with a dashed line symbol

Line features in a feature class representation drawn with a stroke symbol layer and a dash geometric effect

Example: Converting existing symbology



Examples:- Feature

masking for labels (left)- Orientation

of marker symbols (below)



Example: Creating overpasses

For more, see:http://resources.arcgis.com/en/help/main/10.1/index.html#/What_are_representations/00s50000004m000000/“Mapping and Visualization” in ArcGIS Desktop Help


Esri Maps for Office

Add mapping functionality to Microsoft Office documents (Excel, PowerPoint)See http://doc.arcgis.com/en/maps-for-office/


Other Resources

ESRI Mapping Center - http://mappingcenter.esri.com/ESRI Press Books– Designing Better Maps: A Guide for GIS Users– Designed Maps: A Sourcebook for GIS Users

Book Making Maps: A Visual Guide to Map Design for GISEEOS 360 – Computer andAnalytical Cartography(Fall 2015)

Also seehttp://www.gsd.harvard.edu/gis/manual/style/

eeos 381 - spatial databases and gis...

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