senior cartographic researcher, esri professor, university...
TRANSCRIPT
Slide 1
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.
Slide 2
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?
Slide 3
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
Slide 4
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.
Slide 5
Part 1
Differences between
GIS data and cartographic data
15 MINUTES
Slide 6
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.
Slide 7
In other words, we change the representation of the features but not the features
themselves.
Slide 8
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.
Slide 9
Here we can see how changing the representation of roads allows for a better
cartographic display.
Slide 10
Alternate example: DEM Terrain Analysis
For analysis – hydrologic flow analysis with flow accumulation to create a stream
network
For cartography – construct contours from DEM
Slide 11
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.
Slide 12
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.
Slide 13
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.
Slide 14
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.
Slide 15
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.
Slide 16
Multiple DCM products
Terrain analysis
‘Traditional’ topographic views
Slide 17
Multiple DCM products
Town planning
Infrastructure development
Slide 18
Multiple DCM products
Land cover analysis
Site suitability
Slide 19
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
Slide 20
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.
Slide 21
Part 2a
Describing cartographic workflows
10 MINUTES
Slide 22
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
Slide 23
DATACOLLECTION CARTOGRAPHY MAP USE
Information transformations in cartography
Geospatialdata
Geographicalenvironment
Map Map image
CensusGround surveyGPSRemote sensingDigitizing
ReadingAnalysisInterpretation
SelectionGeneralizationSymbolizationLabeling
Transform 2 Transform 3Transform 1
Slide 24
Cartographic data modeling for map production
Map productionprocess
Geographicalenvironment
Conceptualdata model
ArcGISgeodatabase
Map products
Workflow
+
GIS data model
5K OS BaseMap
5K OS BaseMap
250K Road Map
250K Road Map
10K OS TopoMap Series
10K OS TopoMap Series
10K CampusMap
10K CampusMap
Slide 25
DLM – DCM data production workflow
R8
R1R2
R7
R3
R4
R5R6
Number of usersSmall Large
Small
Mapscale
Large
DLM
DCM
Deriveddata model
Slide 26
Map productionprocess
Cartographic data model
REFINEMENT
Graphicrefinement
GraphicplanGraphic
ideation
Map customerand
map purpose
Mapconceptualization
Geographicalenvironment
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.
Slide 27
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?
Slide 28
Part 2b
Modeling GIS data
to support cartographic workflows
25 MINUTES
Slide 29
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
Slide 30
Slide 31
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.
Slide 32
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.
Slide 33
Example: Cultural
CFTID
CFTID
CFTID
CFTID
CFTID
CFTID
Example from one particular theme – Cultural features.
Slide 34
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).
Slide 35
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)
Slide 36
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)
Slide 37
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)
Slide 38
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.)
Slide 39
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)
Slide 40
DEM
Elevation RasterElevation (how to symbolize)
Hillshade RasterValue (how to symbolize)
Slide 41
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?
Slide 42
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
Slide 43
Break
3:00-3:30
Slide 44
Part 3
Cartographic data model
20 MINUTES
Slide 45
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.
Slide 46
Cartographic Feature Type
A type of feature on the map…
…that has unique symbology and/or labeling
Slide 47
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.
Slide 48
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.
Slide 49
Label specifications
Contain the rules for labeling a specific Cartographic Feature Type
Slide 50
Label specs in the Cartography Table
Labeltext
Labelspecifications
Featuregeometry
CartographicFeature Type (CFT)ID & description
Featureclass
Slide 51
Symbol specifications
Contain the rules for symbolizing a specific Cartographic Feature Type
Slide 52
Symbols
Contained in a Microsoft Access database
Named for each Cartographic Feature Type (CFT)
Slide 53
Symbol Specs in the Cartography Table
Featuregeometry
CartographicFeature Type (CFT)ID & description
Featureclass
Labeltext
Labelspecs
Symbolspecifications
Slide 54
The completed Cartography Table in the Base Map Data Model
Slide 55
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
Slide 56
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
Slide 57
Part 3b
Supporting multi-scalemulti-purpose mapping
10 MINUTES
Slide 58
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.
Slide 59
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.
Slide 60
Surface Cover
And you do this for all the map layers that you need for your map.
Slide 61
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.
Slide 62
Part 4
Cartographic workflows in practice
15 MINUTES
Slide 63
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.
Slide 64
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)
Slide 65
CONCLUSION
5 MINUTES
Slide 66
Parting words
Have a plan -> start from a product
Incorporate mapping into your current workflowData compilation / analysis / production
Work with cartographers / project manager / DBAs
Slide 67
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
Slide 68
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
Slide 69
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