In lesson 1 you identified and derived the criteria for the Habitat submodel, one of the three submodels comprising the Bobcat suitability model. The two other submodels, Food and Security, will be viewed in later lessons. In this lesson you will transform the base and derived data to a common scale so that the three criteria for the Habitat submodel can be combined to identify the preference for each location relative to habitat.
This lesson is divided into four sections:
- Opening and editing the ModelBuilder model
- Using the Reclassify tool to transform categorical criteria (land use)
- Using the Rescale by Function tool to transform continuous criteria (slope)
- Using the Rescale by Function tool to transform distance from streams
ArcGIS Spatial Analyst is required for this analysis and you must ensure that it is enabled. See Enabling the Spatial Analyst extension.
This lesson continues on the data that you downloaded in lesson 1. If you have not downloaded the data, see the first section in Lesson 1: Exploring and deriving data.
Opening and editing the ModelBuilder model
- If the SuitabilityModeling map document was closed after lesson 1, reopen it by double-clicking the SuitabilityModeling.mxd file in the SuitabilityModeling folder.
- Open the SuitabilityModel model that you began building in lesson 1 by right-clicking the model and clicking Edit.
Using the Reclassify tool to transform categorical criteria (land use)
Since land use is categorical data, the Reclassify tool will be used to transform the values in the LandUse layer onto a common scale. Once the land use, slope, and distance from streams criteria have been transformed onto the same scale, they can be combined into a single layer for the Habitat submodel of the suitability model. For more information on transforming data, see the Transforming data onto a common preference scale story map.
- The Reclassify tool requires Spatial Analyst, so turn on the extension by first clicking the Customize tab in the ArcMap taskbar. Choose the Extensions option from the drop-down list, and check the Spatial Analyst check box to turn it on.
- Click the ArcToolbox icon on the Standard toolbar. Browse to the Reclassify tool in the Reclass toolset in the Spatial Analyst Tools toolbox.
- Drag the Reclassify tool into the SuitabilityModel model and place it to the right of the LandUse dataset.
- Using the Connect tool , in the SuitabilityModel ModelBuilder model taskbar, connect the LandUse layer to the Reclassify tool. Make the connection by clicking the LandUse layer first, and then click the Reclassify tool. Choose the Input raster option.
- Double-click the Reclassify tool icon to open the tool's dialog box. You can specify file names and additional parameters on the dialog box. Select VALUE from the drop-down list of the Reclass field parameter. Type Transformed_Landuse in the Output raster parameter to name the output raster of transformed values. The model automatically saves the file into the Output.gdb geodatabase. To summarize the input and output layers for the Reclassify tool, specify the parameters as follows:
- Input raster: LandUse
- Reclass field: VALUE
- Output raster: Transformed_Landuse
You could reclassify using the CLASS_NAMES field, but since you are only interested in the resulting reclassed values, to simplify the resulting output table and the default symbology the VALUE field will be used.
- Enter the following new values in the table provided on the Reclassify tool's dialog box.
VALUE New values Descriptions (for reference only) 1
1
Developed, High Intensity
2
1
Developed, Medium Intensity
3
2
Developed, Low Intensity
4
4
Agriculture
5
5
Grassland
6
8
Forest, Deciduous
7
9
Forest, Coniferous
8
10
Forest, Mixed Deciduous-Coniferous
9
6
Scrub/Shrub
10
6
Wetland
11
2
Bare Land
12
2
Water
- Click OK to apply the changes you have made and close the Reclassify tool's dialog box.
- Once the dialog box is closed, right-click the Reclassify tool and click Run to execute the tool.
- Add the Transformed_Landuse layer to the map document by right-clicking the green Transformed_Landuse layer in the model and clicking Add To Display.
- Choose a red-to-green color ramp for the Transformed_Landuse layer to help portray each location's suitability for each land use. Double-click the Transformed_Landuse layer in the table of contents and change the Color Scheme under the Symbology tab. Select the Unique Values display of values from the left panel before choosing a red-to-green color ramp from the drop-down options.
- Visually compare the values of the original input LandUse dataset and the reclassified Transformed_Landuse layer by checking the LandUse layer on and checking and unchecking the Transformed_Landuse layer in the table of contents. Make sure all other layers are turned off (unchecked) in the table of contents. Note how the locations with forested or shrubby cover (green) are more suitable than open or developed lands (red).
Using the Rescale by Function tool to transform continuous criteria (slope)
In order to combine the criteria into a single submodel, recall that each of the criteria must be transformed onto a common scale. Because the slope raster is continuous data, the Rescale by Function tool will be used to transform it onto the same common scale as land use.
- Click the ArcToolbox icon on the Standard toolbar. Browse to the Rescale by Function tool in the Spatial Analyst Tools toolbox in the Reclass toolset.
- Drag the Rescale by Function tool into the SuitabilityModeling model and place it to the right of the Slope layer.
- Using the Connect tool , in the SuitabilityModel model, connect the Slope layer to the Rescale by Function tool. Make the connection by clicking the Slope layer first, and then click the Rescale by Function tool. Choose the Input raster option.
- Double-click the Rescale by Function tool to open the tool's dialog box. Type Transformed_Slope into the Output raster parameter to name the output raster. Select a LogisticGrowth function from the drop-down list of transformation functions. This function will transform steeper slopes as more suitable than flat areas. To summarize the input and output layers for the Rescale by Function tool, specify the parameters as follows:
- Input raster: Slope(2)
- Output raster: Transformed_Slope
- Transformation function: LogisticGrowth
- From scale: 1
- To scale: 10
- Click OK to close the Rescale by Function tool's dialog box.
- Once the dialog box is closed, right-click the Rescale by Function tool and click Run to execute the tool.
- Add the Transformed_Slope output layer to the map document by right-clicking the green Transformed_Slope layer in the model and clicking Add To Display.
- Visually compare the values of the original input Slope dataset and the rescaled Transformed_Slope layer by checking the Slope layer on and checking and unchecking the Transformed_Slope layer in the table of contents. Make sure all other layers are turned off (unchecked) in the table of contents. Note how the suitable areas (green), the locations with steeper slopes, are more suitable than flatter lands.
Using the Rescale by Function tool to transform distance from streams
At this point in the workflow, two of the three criteria have been transformed onto the same common scale. Use the Rescale by Function tool to transform the third, distance from streams, onto the common scale.
- Click the ArcToolbox icon on the Standard toolbar. Browse to Rescale by Function in the Spatial Analyst Tools toolbox in the Reclass toolset.
- Drag the Rescale by Function tool into the SuitabilityModel model and place it to the right of the Distance_Streams layer.
- Using the Connect tool in the SuitabilityModel model, connect the Distance_Streams layer to the second Rescale by Function tool. Make the connection by clicking the Distance_Streams layer first, and then click the Rescale by Function tool. Choose the Input raster option.
- Double-click the second Rescale by Function tool to open the tool's dialog box. Type Transformed_Streams in the Output raster parameter to name the output distance raster. Choose the MSSmall function from the drop-down list of transformation functions. This function will transform areas closer to streams as more suitable than those farther away from streams. To summarize the input and output layers for the second Rescale by Function tool, specify the parameters as follows:
- Input raster: Distance_Streams
- Output raster: Transformed_Streams
- Transformation function: MSSmall
- From scale: 1
- To scale: 10
- Click OK to apply the changes and close the Rescale by Function tool's dialog box.
- Once the dialog box is closed, right-click the second Rescale by Function tool and click Run to execute the tool.
- Add the Transformed_Streams output layer to the map document by right-clicking the green Transformed_Streams layer in the model and clicking Add To Display.
- Visually compare the values of the original input Distance_Streams dataset and the rescaled Transformed_Streams layer by checking the Distance_Streams layer on and checking and unchecking the Transformed_Streams layer in the table of contents. Make sure all other layers are turned off (unchecked) in the table of contents. Note how the locations closer to streams (green) are more suitable than locations farther away.
- Save the SuitabilityModel model by clicking the Save button in the ModelBuilder taskbar. Close the model once it is saved.
- Save the map document by clicking the Save button on the Standard toolbar.
At this point in the suitability modeling workflow, the land use, slope, and distance from streams criteria for the Habitat submodel have been transformed onto a common scale. In Lesson 3: Weighting and combining data, you will combine the transformed criteria into a single layer identifying the relative preference for each location based on the bobcat's habitat needs.