Longley et al., ch. 8 Zeiler, chs. 4 and 5 Object-Orientation Longley et al., ch. 8 Zeiler, chs. 4 and 5

Gateway to the Literature Balram, S. and S. Dragicevic, 2006. Modeling collaborative GIS processes using soft systems theory, UML, and object oriented design. Transactions in GIS, 10(2): 199-218. Whiteaker, T.L., D.R. Maidment, J.L. Goodall and M. Takamatsu, 2006. Integrating Arc Hydro features with a schematic network. Transactions in GIS, 10(2): 219-238.

Gateway to the Literature An, L., M. Linderman, J. Qi, A. Shortridge and J. Liu, 2005. Exploring complexity in a human-environment system: An agent-based spatial model for multidisciplinary and multiscale integration. Annals of the Association of American Geographers, 95(1): 54-79.

Object-Oriented Data Modeling Objects in the real world have “natural” rules and relationships in the computer world Rivers flow downstream Roads handle levels of traffic Land parcels respect landuse laws How to build this intelligence into data structures?

OO Principles things in the world are instances of classes John Smith - human being Harrison Blvd. - street Corvallis - city Mary’s Peak - mountain (Hugh Grant’s hill??) Identity, Inheritance, Encapsulation

OO Principles ( cont. ) Identity classes form hierarchies John Smith is an instance of the class male human beings male human beings are a subclass of human beings human beings are a subclass of mammals mammals are a subclass of fauna each subclass shares the properties of the class

OO Principles ( cont. ) Identity geographic objects often group into complex objects an airport is composed of runways, hangars, terminals a state is composed of counties an area coverage is composed of polygons, arcs, nodes

OO Principles ( cont. ): Inheritance Object can inherit properites old hierarchical database concept objects can inherit properties that are true of all objects of that type e.g., for all polygons new county in Oregon, still can’t pump gas there and can also add new properties e.g., properties true only of a certain class rural county, always has diesel gas

Inheritance in Arc Marine

OO Principles ( cont. ): Encapsulation ( Behavior ) Object can encapsulate behavior (functions) what kinds of behavior? editing rules e.g, corners of a building must be square might apply to all buildings but not all polygons might apply only to some buildings two adjacent objects must have the same common boundary

Object-Orientation Graphic From An et al., 2005, Annals of the AAG

Behavior ( cont. ) attribute rules split and merge rules e.g., range of possible numbers dates in numerical format (only 1 to 12) split and merge rules 1 feature split or 2 features merged, what happens to attributes? e.g., split a street, the lengths of two parts are shares of the total e.g., merge two polygons, their population counts are summed for the combined polygon e.g., merge two polygons, their population densities are averaged, weighted by area

Example Merge Rule

Behavior ( cont. ) editing, attribute, split and merge rules special procedures e.g., procedure to measure areas of polygons associated with polygon object type e.g., procedure to annotate contours specific interaction rules between objects e.g., a liquor store cannot be within 500 m of a school an offramp is required if a street and a freeway intersect at least one stream must flow out of every stream junction

Object-Orientation Graphic From An et al., 2005, Annals of the AAG

A “Smarter” Data Model/Data Structure ArcInfo 7 coverage geometric information not stored in database ArcGIS geodatabase stores geometric information as "shape" attribute Links to object tables of “rules/behaviors” Identity, Inheritance, Encapsulation (Behavior)

Arc Marine Data Model FeatureClass: TimeSeriesPoint ObjectClass: Measurement

TimeSeriesPoint with Measurements 1 *

Relationships

DHI TimeSeries Manager Data Access Bridges dfs ASCII DB GeoDatabase Bridge ... GDB XML

DHI TimeSeries Manager Functionality Data Access Bridges TimeSeries Controls

DHI TimeSeries Manager Arc Atmosphere Arc Hydro MIKE 21 Arc Marine Geodatabase ArcGIS MIKE 11 TimeSeries Manager Data Access Bridges Slide courtesy of Michael Blongewicz, DHI-Environment dfs0 MIKE GIS MIKE Basin

Data Model Review A practical working template A starting point for creating a geodatabase An aid to simplify the integration of similar datasets A way to facilitate the exchange of data A support to existing standards Feature ObjectID Geometry LandObject LandObjectID TransactionID SystemStartDate OfficialStartDate OfficialEndDate SurveyPoint SurveyBoundary Point Measurement Computation Coordinate Project Geodatabase * The data models that ESRI works to create are a practical template for implementing a GIS project. They serve as a good starting point to help you create a geodatabase, or to use as a reference in refining your data model. When multiple people or organizations use the same data model the resulting databases have similar feature names and attributes, providing for easier interoperability. A good datamodel design can be key to making better decisions based on available data or geographic information, While supporting existing standards.

Use of a Data Model in an Analysis Model Model Builder geoprocessing diagrams for workflow Geoprocessing models can be used to create schema, and are most commonly used to store work flow processes. Once you have a data model design that you are happy with, the work flow, or GIS functionality that you employ on the data, it can be preserved in this environment, and more easily shared with others. Notice the toolbox storing the Geoprocessing model can be represented and appended to the Geodatabase itself.

3D Interpolation tool Sample resulting from collaboration between data models and ESRI developer Network (EDN) New tools based on data model prototypes and case study testing.

3D points displayed in volume space

ArcGIS Data Models Web site http://support.esri.com/datamodels Over 25 industry-specific data models Conceptual and logical diagrams Case studies, Tips and Tricks documents These data models are hosted at the support center website where you can find a description of the industry model, links to interest groups, forums, and key points of contact. In addition, at the website you will find available for download all of the case studies and design template documents that result from the collaborations that ESRI has with external groups to create these models.

Thematic Content - layer stack Thematic groupings of oceanographic data sets Identifying the thematic groupings of the GIS ‘layer stack’ is a useful initial step towards giving names to the common elements that will be most important in the geodatabase. The layer stack is often the result of collaboration with many different people and organizations to assess the most useful layers that will be a part of the GIS analysis.

Arc Marine Thematic Layers

Arc Marine Thematic Layers