senior cartographic researcher, esri professor, university ... · cartography: modeling gis data...

Cartography: Modeling GIS data for Mapmaking

Aileen Buckley, Ph.D.Senior Cartographic Researcher, ESRI

Barbara Buttenfield, Ph.D.Professor, University of Colorado-Boulder

Thank you coming to learn more about how to model GIS data for map making. My

name is Aileen Buckley, I’m a cartographic researcher at ESRI and for the past two plus

years I have been working with Charlie Frye on the development of the data model for

multipurpose multiscale mapping. Charlie is head of the Cartography Research Team at

ESRI and has been working on the development of this data model for almost four years

now. (Point out Charlie.) We have also been working with Barbara Buttenfield and her

students from the University of Colorado-Boulder. Before we get started, babs and I will

take a few minutes to introduce ourselves and then we would like to learn a little more

about all of you.

What kind of maps do you make?

Bike Map

Trail Map

Crime Hot Spots

Suitability Map

AnalysisResults

AtlasThematic Map

Census Data

ThematicMaps

Atlas Reference Map

Topo Map

ReferenceMaps

Special UseMaps

Ask the audience about themselves:

How many make maps regularly?

How many use only GIS software to do that?

How many have a database background?

How many attended the “Cartography: Making Better Maps” session in the morning

today?

Other questions?

Agenda for Seminar

1:30-2:05 IntroductionPart 1: Differences between GIS data and cartographicdataPart 2a: Describing cartographic workflows

2:05-2:20 Exercise2:20-2:45 Part 2b: Modeling GIS data to support cartographic

workflows2:45-3:00 Exercise3:00-3:30 Break3:30-3:50 Part 3a: Cartographic data model3:50-4:05 Exercise4:05-4:30 Part 3b: Supporting multi-scale multi-purpose mapping

Part 4: Cartographic workflows in practice4:30-4:45 Exercise4:45-5:00 Conclusion

Before we get started, let’s go over the schedule for today’s seminar as well as a few

logistics.

Schedule

Restrooms

Break

Pre-conference seminar materials

Slides

Exercises

Cartography Data Model

Cartography Tables

References

Web URL

Because we cannot go into as much detail as we would like in the time we have together,

we have provided you with lots of resources that you can take with you and refer to later.

These are compiled in the book you have in front of you. In additional to all the slides

you will see today, and their related notes, you also have the exercise worksheets and all

the answers (don’t peek at these until after the exercises are complete!), the data model

poster and schema, an example Cartography table, and a list of references that you can

draw on, including those you can find on the ESRI web site.

Part 1

Differences between

GIS data and cartographic data

15 MINUTES

Differences between GIS and cartographic data

Processing cartographic data is different from processing GIS data

Representations of data for graphic displaySymbols

Labels

Geoprocessing for cartography not spatial analysisClassification

Selection by attribute

Selection by size

Changing the view on the data as opposed to changing the data in the database

Let’s start by talking about how GIS data and cartographic data are different.

One thing that distinguishes cartographic and GIS data are the types of processes used to

manipulate the data and more importantly the purposes of the processes. With GIS data,

the objective is often either data management of data analysis. With cartographic data,

the processes are used to modify the data so it can be displayed graphically, that is,

optimized for symbology and labeling. Sometimes we use the same geoprocessing tools

as for analysis, such as classification and selection, but the aim for cartography is to get

the best representation of the data for display on a map.

In essence, the goal is to modify the view of the data but not necessarily modify the

original data in the database.

In other words, we change the representation of the features but not the features

themselves.

Changing the representation changes the message

For analysis –dissolve roads so you can validate connectivity in the network

For cartography –dissolve roads so you can use a continuous road symbol

When we change the representation of the data, we change its meaning. The meaning in

a cartographic sense is related to how the features are displayed and understood by the

map reader. For example, if we were to try and map roads with a dashed line symbol, we

might first want to dissolve the roads to make them fewer features. That way, the dashed

line will look more continuous. Alternatively, for GIS analysis, you might dissolve the

roads to learn more their network characteristics.

Here we can see how changing the representation of roads allows for a better

cartographic display.

Alternate example: DEM Terrain Analysis

For analysis – hydrologic flow analysis with flow accumulation to create a stream

network

For cartography – construct contours from DEM

So what happens is this: The GIS data is sort of like the wire frame of the data. The

cartographic data is modified so it can be presented on a map, complete with symbols and

labels, and potentially also geoprocessed in preparation for graphic display.

Cartographic

Modifications and Enhancements

5 m resolutionDL:M

5 m resolutionDL:M

25 m resolutionDLM

25 m resolutionDLM

Digital LandscapeModels

Digital CartographicModels

Map / AtlasProducts

1 km resolutionDLM

1 km resolutionDLM

MapProduction

DCM_Campus10KDCM_Campus10K

Real WorldReal WorldReal World

DCM_5KDCM_5K

DCM_10KtopoDCM_10Ktopo

5K OS BaseMap

10K OS TopoMap Series

10K CampusMap

DCM_250KDCM_250K

DCM_100KDCM_100K

DCM_50KDCM_50K

DCM_10MillionDCM_10Million

50K Wall Map

100K Recreation Map

250K Road Map

10M World Wall Map

Geoprocessing Cartographic Finishing

Derived 10mDLM

Derived 10mDLM

A longstanding issue for cartographers is that national mapping agencies don’t have

compiled DLMs – the data we work with is compiled from paper maps.

There are a couple of impacts from this:

• the data we use is already tied to a particular map product, and

• cartographic enhancements and modifications are so deeply embedded in the

database that it shard to distinguish the rules for collection from the specifications

for mapping.

DLM - DCM

Digital Landscape Modelor DLM

GIS database (wire frame model)

compiled from source information registered to the ground

several standardized scales

accuracy and resolutionare of primary concern

Digital Cartographic Model or DCM

stored in a product database (for a map)

enhanced and modified from DLM

specific to a map’s purpose

graphic clarity and visual integrity are of primary concern

To help distinguish between these two types of data, we sometimes use the terms digital

landscape model and digital cartographic model.

The digital landscape model is that wire frame representation of the data. It is the GIS

data that was complied from a source that can be referenced to the ground. It may come

in several standardized scales that relate to the requirements of the organization or agency

collecting the data. For the GIS data, positional and attribute accuracy are of primary

concern and adequate resolution of the data is required for its various applications.

The digital cartographic model is a product database that is derived for a specific map

product. It contains often a subset of data from the digital landscape model that has been

enhanced or modified for the map’s purpose. Because the data are used for mapping, the

primary concern for digital cartographic data is graphic clarity and visual integrity.

Types of maps

Number of users and uses(indicates the level of general application)

Number ofmap features

(and thesubsequent complexity

of relationships among them)

Bike Map

Trail Map

Crime Hot Spots

Suitability Map

AnalysisResults

AtlasThematic Map

Census Data

ThematicMaps

Low High

High

Low

Atlas Reference Map

Topo Map

ReferenceMaps

Special UseMaps

Introduce the concept of lots of maps that can come from one DLM.

GIS database

Source -> DLM -> DCM

Real world example:

Orthophotos, satellite imagery, LIDAR and DEM data are examples of the data that

would be in the DLM – these is used as source data to create the base polygon, vector and

line feature datasets.

Different types of maps could be created from the DLM data – this results in DCM data.

The GIS database can contain all of this information.

Multiple DCM products

Terrain analysis

‘Traditional’ topographic views


Town planning

Infrastructure development


Land cover analysis

Site suitability

Summarizing Part 1

Processing cartographic data is different from processing GIS dataThe intent is to change the view on the data as opposed to change the data in the databaseChanging the representation changes the messageDLM = GIS database; DCM = map product databaseLots of maps and their DCMs can come from one DLM

Digital LandscapeModels

CartographicModifications and

EnhancementsDigital Cartographic

ModelsMap / Atlas

ProductsMap

Production

LandlineDB

LandlineDB

Real WorldReal WorldReal World

3rd PartyDatasets3rd PartyDatasets

ObjectGeneralization

Sourcedata

Sourcedata

DCM_10KtopoDCM_10Ktopo

DCM_Campus10KDCM_Campus10K

DCM_10KwebDCM_10Kweb

RulesRules

RulesRulesDerived 10 m

DLMDerived 10 m

DLM

Selection GeneralizationRestructuring the data

RulesRules

Derived 50 mDLM

Derived 50 mDLM

RulesRules

ModelGeneralization

DDMSDDMS

MasterMapMasterMap

RulesRules

RulesRules

DLM Archive DBDLM Archive DB

DLM Archive DB

Ordnance Survey Great Britain example.

Part 2a

Describing cartographic workflows

10 MINUTES

Describing cartographic workflows

The workflows are intended to transform information

DLM -> DCM -> final map product

As you go through the transformations, you:move from multi-purpose to targeted use

may move across limited scale ranges

Design the workflow and model the data before you go into production

DATACOLLECTION CARTOGRAPHY MAP USE

Information transformations in cartography

Geospatialdata

Geographicalenvironment

Map Map image

CensusGround surveyGPSRemote sensingDigitizing

ReadingAnalysisInterpretation

SelectionGeneralizationSymbolizationLabeling

Transform 2 Transform 3Transform 1

Cartographic data modeling for map production

Map productionprocess


Conceptualdata model

ArcGISgeodatabase

Map products

Workflow

+

GIS data model

5K OS BaseMap

5K OS BaseMap

250K Road Map

250K Road Map



10K CampusMap

10K CampusMap

DLM – DCM data production workflow

R8

R1R2

R7

R3

R4

R5R6

Number of usersSmall Large

Small

Mapscale

Large

DLM

DCM

Deriveddata model

Map productionprocess

Cartographic data model

REFINEMENT

Graphicrefinement

GraphicplanGraphic

ideation

Map customerand

map purpose

Mapconceptualization


Map

Workflow

Conceptualdata model

ArcGISgeodatabase

Map conceptualization process

Finalproduct

Publication

In summary, we can see that it is now possible to see how cartographic data modeling

and workflows fit together with map conceptualization. Map making is not a linear

process, and simply stringing together the decisions made to conceptualize the map and

model the data does not usually result in a product that is satisfactory to the cartographer

the first time through. Once the results of the various graphic decisions can be seen

simultaneously, multiple iterations of the map are often made in an effort to refine the

graphic display. The map maker may choose to refine the initial concept (in which case

the loop cycles back through the map conceptualization process) or the map

symbolization (in which case the loop cycles through the map production but not the

conceptualization process).

With this more complete picture of fluid process of map making, it is now possible to

apply this understanding in the automation of map production. It is can then be

determined to what extent the information model for maps supports map making.

Exercise

Discuss how mapping is integrated into your GIS production workflow

Map product specifications

GIS data or cartographic data?

To what extent is your cartographic workflow modeled?

By whom?

Part 2b

Modeling GIS data

to support cartographic workflows

25 MINUTES

Modeling GIS data to support cartographic workflows

What does this all look like in an ArcGIS environment?

What themes are relevant for the map purpose?What cartographic features?

What cartographic attributes?

How do you modify the DLM to create the DCM?We talked about GIS data to cartographic data

This is where the cartographic geoprocessing happenS

Cartographic attributes

Any Feature Class

Coded Value Domain

Geom ID Attributes... Type

43210 0

1242

01234 Description...

Description...Description...Description...Description...

Each Type of Cartographic Feature has a number and a description in the Coded Value domain. Integer value in the feature class is faster to display.

PrisonParkCemeteryMallStrip Mall

In an ArcGIS environment -- how do you enrich the data? Through attribute

enhancement. This leads to the development of Coded Value domains. At this point, you

can take a look at the example domains at the end of this handout.

Labels

Symbols

In a relational environment, you do this through table joins and relationship classes. For

representation, you would attach symbols and labels to the features through these types of

joins and relationships.

Example: Cultural

CFTID

CFTID

CFTID

CFTID

CFTID

CFTID

Example from one particular theme – Cultural features.

Cultural

Cultural Features (Buildings, Areas, Points of Interest)

Type (how to symbolize and for some kinds of cultural features, it is the label)

Name (for label)

Size or Area (used to set threshold for which features are shown)

You may have the attributes you need in your database through a relationship to a table

but for mapping, you need to pull them directly into the DCM so they draw more quickly.

For example, export the DLM data to a new feature class – delete the fields you don’t

need, add the fields you do need and populate them, make sure they are in the format that

you need them in (e.g., concatenate the fields if you need to).

Boundaries

Boundary Lines (any level)Type (how to symbolize)L_Name (left/upper label)R_Name (right/lower label)Annotation must be produced to ensure proper identification

Legal Areas (any type)Type (how to symbolize and what kind of label)Name (for label)WithinMSA (Boolean for drawing/labeling)

City PointsName (how to label)Size (how to symbolize and label)Special Type (how to label or symbolize)WithinMSA (Boolean for drawing/labeling)

Transportation

RoadsClass (how to symbolize)Type (determine correct kind of label)Name (for text labels)Highway Route Number (for highway labels)UrbanRural (for multipurpose data which may be represented differently within urban areas)Label String (store exactly what is to be labeled and then the Name does not need to be edited/compromised)

RailroadsType (how to symbolize)Owner (how to label)

Hydrography

Area FeaturesName (how to label)Type (how to symbolize and which features to label, and sometimes is the label)Area (used to set threshold for which features are shown)

Line FeaturesName (how to label)Type (how to symbolize)Size, Discharge, or Level (how to symbolize or as a filter for which features to show—dendritic branch count and Stream Order are not useful here)

Surface Overlays

Land cover/Land use/Zoning/Flood zones/Homeland security (risk), etc.

Type (how to symbolize)Abbreviated Type (for labeling, e.g., soils, surface geology, etc.)Area (used to set threshold for which features are shown or get labels)Uncertainty (used to modify symbology of either features or labels to show reliability, etc.)

Terrain

ContoursElevation (for labels)Units (for labels or conversion when mix of data is present)Type (for symbol , includes index, intermediate, depression, etc.)LabelYN (optional: for determining whether to draw a gap or a line, gaps are where labels get placed)

Spot ElevationsType (how to symbolize)Elevation (part of label)Units (part of label)

DEM

Elevation RasterElevation (how to symbolize)

Hillshade RasterValue (how to symbolize)

Summarizing Part 2

The workflows are intended to transform informationDLM -> DCM -> final map product

As you go through the transformations, you:move from multi-purpose to targeted usemay move across limited scale ranges

Design the workflow and model the data before you go into productionModeling GIS data to support cartographic workflowsWhat does this all look like in an ArcGIS environment?What themes are relevant for the map purpose?

What cartographic features?What cartographic attributes?

How do you modify the DLM to create the DCM?We talked about GIS data to cartographic dataThis is where the cartographic geoprocessing happens

What are cartographic attributes for each of the feature classes?

Exercise

2:45-3:00

Scenario – specify the DCM requirements for a bike map

One of these maps – tourists, participants, organizers

Each group describe all themes

Compile the answers together

Break

3:00-3:30

Part 3

Cartographic data model

20 MINUTES

Cartographic Data Model

Cartographic Feature Types

Symbols and Labels

Cartography TableLinks the feature to its map representation (symbol + label)

Construct the Basemap Data Model together

Let’s construct the Cartography Data Model together.

The Cartography Table joins to the DCM feature classes that will be on the map.

Cartographic Feature Type

A type of feature on the map…

…that has unique symbology and/or labeling

Cartographic Feature Type ID (CFTID) in the Cartography Table

Each cartographic feature type has a …

Unique ID

Unique description

The cartographic feature type is a database feature that is used in cartographic abstraction

to communicate the position and characteristics of geographic features and their

relationships. The special thing about these features is that they are the features on the

map – which may or may not be the same as the features you use for spatial data

inventory or analysis. For example, on a topographic map, you will often see the

hypsography symbolized with contour lines. The rules for this representation of

elevation -- that is, color and width of the lines and font size and style of the labels -- are

stored in the Cartography Table. On the other hand, you might be interested in using

hypsography for analysis, say in watershed analysis -- in this case, you would likely use

the digital model of the terrain – the DEM -- instead of the cartographic representation.

The Cartographic Feature Types in the table are unique and each cartographic feature

type is identified by a CFT_ID. Associated with each feature type is a unique

description. These CFTs and their descriptions encompass what is sometimes called a

complex domain – that is, it contains the definition of both features and their valid

attributes. This table provides the content for the coded value domain that can be used

with the geodatabase and the table is also separated into domains for each feature types

so that there is no duplication and there is completeness, so the table is normalized

overall.

Cartographic Feature Types (CFTs) in the Cartography Table

Featuregeometry

CartographicFeature Type (CFT)ID & description

Featureclass

Each row defines one CFT – it has a feature geometry, it has a unique description and

you can see what would be shown on the map.

Label specifications

Contain the rules for labeling a specific Cartographic Feature Type

Label specs in the Cartography Table

Labeltext

Labelspecifications

Featuregeometry


Featureclass

Symbol specifications

Contain the rules for symbolizing a specific Cartographic Feature Type

Symbols

Contained in a Microsoft Access database

Named for each Cartographic Feature Type (CFT)

Symbol Specs in the Cartography Table

Featuregeometry


Featureclass

Labeltext

Labelspecs

Symbolspecifications

The completed Cartography Table in the Base Map Data Model

Summarizing the Cartographic Data Model

Identify the cartographic features

Assign a unique CFTID and description

Assign symbology

Assign labeling

Compile the info into the Cartography Table

Exercise

3:50-4:05

Bike map – define the symbology and labeling specifications

Define these:Race route

Roads

Landmarks

Facilities (restrooms, restaurants, toilets, First Aid, etc…)

Terrain

Part 3b

Supporting multi-scalemulti-purpose mapping

10 MINUTES

Supporting multi-purpose multi-scale mapping

Cartography Table content can be extended across scales and across purposes

Add rows and columns to Cartography TableRows -- Add new cartographic feature types

Columns -- Alternate symbology and labeling –multi-scale & multi-purpose

SQL query stringsDefinition queries for filtering

Label strings for labeling

We have the Cartography Data Model and now we want to extend this to support multi-

scale multi-purpose mapping. This is simple. Simply add new columns (for symbol and

label changes) and rows (for new features on the map). And you may need to create new

styles.

Features

Labels/Anno

Notes

Scales

First conceptualize what you want on the map at the various scales. The point is to

conceptualize before you start going through the process. First figure out what gets

added at what scales, then what the representation is – pt, line, poly, text. You do this

outside of a database environment – this is a conceptualization exercise.

Surface Cover

And you do this for all the map layers that you need for your map.

Other specifications in the Cartography Table

Definition QueriesThis selects the features to be shown on the map at a particular scale

SQL Query StringsThis defines which features are being labeled

Label ExpressionsThis defines how a label looks and which attributes are used to construct it

Scale RangeThis specifies the scale at which the features will be shown

We are essentially separating design from production – hopefully leads to less individual

refinement. Much of this work goes on outside the ArcGIS environment – with a view

towards the ability to implement it within ArcGIS at some point.

Part 4

Cartographic workflows in practice

15 MINUTES

Example

Here’s what you selected

Here’s how you want to symbolize them

Here’s the Cartography Table looks like

Here’s what the CFTIDs look like

Here’s what the style and the spec in the CT looks like

Here’s what the text and the spec in the CT looks like

Here’s the final map

This will now allow you to move from the original base map data model to be able to

create multiple maps with multiple scales and purposes.

Exercise

DiscussionQ&A

Exit pollWhat parts of this process might be the most problematic in your organization?

What parts do you think might be most challenging for non-institutional reasons?

Go through various examplesWalk through the lineage of DLM to some carto feature types (contours, interstate hwy from the Census database from CFCC – add name, extract some features using calculate statement)

CONCLUSION

5 MINUTES

Parting words

Have a plan -> start from a product

Incorporate mapping into your current workflowData compilation / analysis / production

Work with cartographers / project manager / DBAs

Resources

Existing resourcesSlidesExercises

Through the ESRI web site - Base map data model web page

Cartographic Data ModelCartography TablesGeoprocessing tools, models, scripts – also on Geoprocessing web pageCase studiesBest cartographic practices

User communityCase studies / best cartographic practicesGeoprocessing tools, models, scriptsModel & schema

Other sessions

For data modeling:Cartographic data model session

Data Modeling for Large-scale Maps ands Map Production – Wed 7/27 1:30-3:00

Other data model sessionsAddress data model – for names management-- Wed 7/27 10:30-12:00ArcHydro data model – for understanding a data model and seeing how it can be consumed cartographically

For map production:Cartography technical sessionsPLTS sessions – Production Line Tool Set

http://support.esri.com > Downloads > Data Models

http://support.esri.com > Downloads > Geoprocessing

http://http://support.esri.comsupport.esri.com > > DownloadsDownloads > > Data ModelsData Models

http://support.esri.comhttp://support.esri.com > > DownloadsDownloads > Geoprocessing> Geoprocessing

senior cartographic researcher, esri professor, university ... · cartography: modeling gis data...

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