EATS4400.03 Geographic Information Systems and Data Integration Lecture Three 2011 winter Vector-Based Spatial Analysis: Model Modeling processes ArcGIS Modelbuilder Cheng. Q., Earth and Space Science and Engineering, qiuming@yorku.ca Reading materials Labs. 1& 2 notes Website Link to the An overview of Model builder http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm? TopicName=An_overview_of_ModelBuilder Spatial Analysis What is Spatial Analysis? (From Wikipedia, the free encyclopedia) Spatial analysis or spatial statistics includes any of the formal techniques which study entities using their topological, geometric, or geographic properties. Patterns and anomalies recognition Spatial decision support Optimization and prediction Assessment Network Analysis 1
Spatial Modeling Spatial Modeling (GIS Modeling) It is the set of procedures that simulates real-world conditions within a GIS using the spatial relationships of geographic features. Spatial Modeling Definitions Spatial modeling involves the construction of explanatory and predictive models for statistical testing (Chou, p. 24) Representation of a process (Fowler, 1997) Formal expression of the essential elements of some problem in either physical or mathematical terms (Jeffers, 1988) Simplified picture of reality..as a tool to solve problems (Jorgensen, 1994) Spatial Modeling Definitions Formal expression of the essential elements of some problem in either physical or mathematical terms (Jeffers, 1988) The studying of landscape processes using mathematical algorithms written in computer code (Burroughs, 1986) Spatial Data Integration Mapping areas for drilling in mining industry The processes of model development, formulation and application to simulate the system behavior of the real world. Work flow Example of GIS Modeling Data sets Example of GIS Modeling Landuse Elevation Recreation Schools Index value = 0.125* Reclassified Landuse + 0.125* Reclassified Slop + 0.5*Reclassified Recreation + 0.25*Reclassified Schools Calculate Slope Find dist from recreation Find dist from school 2
Example of GIS Modeling Result - As a result of output image, 3 candidates of optimal site for the new school have been selected. - Bright blue color indicates high value of pixel (more suitable) in output image, dark indicates that there is no data. - When considering another condition, the best site can be determined. Map showing the AUs of the CARA is color-coded for mean estimated undiscovered oil. Only areas north of the Arctic Circle are included in the estimates. Black lines indicate AU boundaries. A General Spatial Modeling Processes Stating the problem Breaking the problem down Exploring input datasets Determining analysis processes Verifying the model s result Map showing the AUs of the CARA is color-coded for mean estimated undiscovered gas. Only areas north of the Arctic Circle are included in the estimates. AU labels are the same as in table S1. Black lines indicate AU boundaries. Implementing the result and reporting 3
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ModelBuilder is an application in which you create, edit, and manage models. Link to the An overview of Model builder http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?topicname=an_overview_of_modelbuilder Modeling Process: tool, parameters (variables) A Conceptual overview of a Model An Example of a Model Advantages of a ModelBuilder in GIS Design a model Automate the geoprocessing workflow Share geoprocessing knowledge Record and document methodology Add complexity as needed Implement a model Create a model containing methods & procedures to be shared with others Show the process used to create output (flow diagrams) In ModelBuilder, models are represented as flow charts with different symbols 5
ModelBuilder window: where you edit, test and run models Auto Layout Zoom In Full Extent Zoom out Navigate Continuous Zoom Select Run There are two types of model elements: Tools Variables Add Connection Not all parameters have been supplied for the tool to run. All parameters have been supplied. There are two types of variables: Data: Reference data on disk or in an in-memory layer Values: Everything else, such as numbers, strings Project data is data that you add to the model Maps and Tables Values that are input to a tool For example, the buffer distance input The ModelBuilder Interface Model elements have 4 states Not ready to run (parameters aren t t defined) Input tool output Ready to run (all elements are colored) Already run (elements are colored and shaded) Implmenting Usually referred to as Derived Data Start building your model! First, plan what you want to do What data will you need? What processes will you run on each dataset? 6
List of Toolbox Set of Tools 7
Examples for Table An Interactive Model For Vector base data ModelBuilder window 8
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