How to Perform Raster Site Selection/Suitability Analysis in ArcGIS? A Complete Tutorial.

Introduction

This tutorial will guide you through the process of performing raster site selection and suitability analysis in ArcGIS. It covers essential steps such as data collection, geoprocessing settings, and scoring various factors like population density, slope, and proximity to hospitals and roads. This analysis is crucial for making informed decisions in urban planning, healthcare accessibility, and environmental management.

Step 1: Data Collection

To begin your analysis, you will need to gather the necessary datasets. You can download the required data from the following sources:

• Block Groups: ArcGIS Block Groups
• Landcover Type: MRLC Landcover
• Roads: Census Tiger Line Files
• Digital Elevation Model (DEM): National Map Downloader
• Ohio Hospitals: Ohio Hospitals GIS Data

Once you have downloaded the data, organize it in a designated folder for easy access.

Step 2: Formulation and Flowchart Creation

Next, create a flowchart to outline the steps of your analysis. This will serve as a roadmap for your project. Ensure your flowchart includes:

• Data input sources
• Processing steps for each dataset
• Final outputs (suitability maps)

Step 3: Geoprocessing Settings

Before diving into calculations, set up your geoprocessing environment:

• Open ArcGIS and load your datasets.
• Adjust the settings for raster analysis by specifying the coordinate system and cell size according to your project needs.

Step 4: Calculate Population Density Raster

To assess population density:

1. Load your block group data into ArcGIS.
2. Use the Spatial Analyst tool to create a population density raster:
   • Navigate to Spatial Analyst Tools > Density > Kernel Density.
   • Input the block group features and set parameters based on your study area.

Step 5: Rate and Score Population Density Raster

Once you have the population density raster:

• Normalize the raster values to create a score ranging from 1 to 5, where 5 indicates the highest population density.
• Use the Reclassify tool in ArcGIS to assign scores.

Step 6: Calculate Slope from DEM

To analyze slope:

1. Load your Digital Elevation Model (DEM) into ArcGIS.
2. Use the Spatial Analyst tool to compute slope:
   • Go to Spatial Analyst Tools > Surface > Slope.

Step 7: Rate and Score Slope

After calculating the slope:

• Similar to the population density scoring, normalize and reclassify the slope values.
• Assign scores based on suitability criteria (e.g., flat areas might score higher).

Step 8: Proximity to Hospitals

To evaluate proximity to hospitals:

1. Use the Euclidean Distance tool:
   • Access Spatial Analyst Tools > Distance > Euclidean Distance.
   • Input the hospital locations.

Step 9: Rate and Score Proximity to Hospitals

Once you have the distance raster for hospitals:

• Reclassify the values to create a scoring system where closer proximity receives a higher score.

Step 10: Proximity to Roads

Repeat the process for roads:

1. Use the Euclidean Distance tool to calculate proximity to roads.
2. Process the output raster similarly to assign scores.

Step 11: Rate and Score Proximity to Roads

Reclassify the proximity raster for roads, ensuring that closer areas receive higher scores.

Step 12: Combine Rated Factors to Create a Suitability Map

Finally, overlay all the scored rasters:

1. Use the Raster Calculator to combine the scored layers.
2. Assign weights to each factor based on their importance to your analysis.

Conclusion

In this tutorial, you learned how to perform a raster site selection and suitability analysis in ArcGIS. By collecting relevant data, calculating necessary metrics, and combining these into a suitability map, you can effectively assess various locations for specific needs. For further exploration, consider applying different weighting methods or incorporating additional datasets to refine your analysis.