Latest Contributions by SteveLynch

A suitability modeling workflow helps you find the best locations for a specific purpose. For example, you can use it to choose sites for housing developments, schools, corporate headquarters, wildlife conservation, or fire prevention. No matter what the application is, the general process is similar.   ArcGIS Pro’s Suitability Modeler makes this modelling process efficient by using raster functions to transform criteria and generate suitability maps. These raster functions work quickly because the data aren't saved to disk. However, when you reach the “Locate” stage of your modeling project, you’ll need to use data that has been saved (persisted) to disk. The modeling workflow is outlined below.   Four Main Steps to Create a Suitability Model Prepare Criteria Data: Gather and organize the data that will be used to evaluate locations. Transform Criteria Values: Convert each criterion’s values to a common suitability scale so they can be compared. Weight and Combine Criteria: Assign importance to each criterion, then combine them to create a suitability map. Identify Suitable Areas using Locate: Use the suitability map to locate the best areas for your intended purpose. Raster Functions are used in Steps 2 and 3 Steps 2 and 3 use raster functions, which process data in real-time without creating new files. These functions apply changes "on the fly" as you view and change the data, making the process faster and saving storage space. Finalizing Your Suitability Map in Step 3 When you’re satisfied with the suitability map, save it to disk by clicking the Run button in the Suitability pane. After saving (click the Run button in the Suitability pane), proceed to Step 4 to identify the best locations. The locate step cannot be done using the suitability map raster function, and that is why it has to be converted to a full resolution raster dataset on disk.     ... View more

When building a suitability model, you work with different criteria—such as elevation (measured in meters above sea-level), land use (described using text), and distance from roads (measured in miles). Because these criteria use different units and formats, you must first transform them to a common scale to compare and combine them effectively. Setting Up the Suitability Scale In the Suitability Modeler  application, you start by defining the range for your suitability scale on the Settings tab. By default, this scale ranges from 1 to 10. This scale helps you express the relative importance of different values within each criterion.   Transforming Criteria On the Suitability tab, you’ll transform each criterion to fit this common scale: First Criterion Transformation: When you transform the first criterion, a new layer is created with values ranging from 1 to 10 (using the default suitability scale). The suitability map at this stage is simply a copy of this transformed layer, since only one criterion is included. Adding More Criteria: When you transform the second criterion, another layer is created, with values ranging from 1 to 10 (suitability scale), and is added to the suitability map. Now, the suitability map’s range expands (for example, from 2 to 20) because it combines the values from both criteria. Finally transform and add the third criterion. Applying Weights If your criteria have different levels of importance, you can assign weights to them. For example, if all criteria have a weight of 1, they contribute equally. If a criterion is more important, you assign it a higher weight. The transformed layer for each criterion is multiplied by its weight, and the suitability map is the sum of all weighted transformed layers.   Interpreting the Suitability Map On the final suitability map: Low values (shown in red) indicate areas that are less suitable to build a ... High values (shown in green) indicate areas that are more suitable to build a ... This process ensures that all criteria, regardless of their original units or formats, are fairly and consistently compared in your suitability analysis.     ... View more

In ArcGIS Pro's Suitability Modeler, the output layers are automatically updated whenever a transformation or weight is applied or changed, provided that the Auto Calculate option is checked on the Suitability ribbon. This is the default behavior. However, this automatic updating may not be desired in all cases. For example, if you are assigning the suitability values for each land use type, you may not want the maps to update with each assignment but instead wait until you assign all the suitability values for all the land use types.  To manually control when the updating is to take place, uncheck Auto Calculate., When unchecked the following occurs: the graph in the Transformation Pane will update when any parameter is changed, the Suitability map and the transformed raster layer will not update, which'll speed up things while you are exploring parameters, weights can also be changed without the maps being recalculated and redrawn.   Unchecking Auto Calculate, allows you to quickly refine your criteria without waiting for the maps to refresh after each adjustment. Once you are satisfied with your changes, simply click the Calculate button   on the ribbon to apply the changes and all the affected maps and graphs will also update. ... View more

I have criteria which are already transformed to a common scale, how can I use them in Suitability Modeler to create a suitability map and find the most suitable locations? We can use the Submodels input type and treat the transformed criteria as submodels and in so doing avoid the transformation step. On the Settings tab of the Suitability Modeler, change the Model input type from Criteria to Submodels Then on the Suitability tab, add the transformed criteria.   A suitability map is automatically created after each transformed criterion (or submodel), is added. Then click the Run button to convert the raster function suitability map to a persisted raster dataset. Then use the Locate tab to identify the best locations from the suitability map that was created by the transformed criteria. ... View more

When using the Suitability Modeler in ArcGIS Pro, the criteria must be transformed onto a common scale, and this is done on the Transformation Pane. These transformed criteria are combined to create the suitability map. Unless explicitly set, all these layers are processed as raster functions,  which processes raster data in real-time without creating a new file on disk. Instead of writing a new permanent raster, functions are applied "on the fly" as you view the data, which is faster and saves storage space.  However, if you want to use the transformed rasters outside the Suitability Modeler application, you should check the Save transformed dataset when model is run option. This "save" will take place when the Run button on the Suitability tab is clicked. This "Run" operation will also convert the suitability raster function to a raster dataset.       ... View more