SPATIAL ANALYST Prepared by: Jennifer McKee With support from: NSF DUE-0903270 in partnership with: Geospatial Technician Education Through Virginia’s Community Colleges (GTEVCC) SPATIAL ANALYST • ArcGIS Extension • Provides spatial analysis & modeling tools for vector & raster data • Examples: – Creating new data from existing, e.g. slope or hillshade raster from DEM – Performing distance & cost-of-travel analyses – Interpolate data values based on sample (point) data HOW TO ACCESS S.A. TOOLS • ArcToolbox – Must search for tool if location unknown • Model Builder – Use tools or scripts in models • Python – interactive command line or script • Raster Calculator – for simple map algebra S.A. TOOLSETS • Broken down into catergories by ESRI Conditional Density Distance Extraction Generalization Groundwater Hydrology Interpolation Local Map Algebra Math General Math Bitwise Math Logical Math Trigonometric Multivariate Neighborhood Overlay Raster Creation Reclass Solar Radiation Surface Zonal For greater details see ArcGIS 10 help or online resource center ACCESSING S.A. TOOLS RASTER CALCULATOR • Simple Math Algebra • Use interface – correct syntax is required, including spaces R.C. EXAMPLE • Want to query DEM to locate all areas with 600 meters or greater elevation "eggleston" >= 600 • Results in boolean output: 1 = true, 0 = false R.C. EXAMPLE CONTINUED • Combining multiple boolean outputs to find an area that meets your criteria • For example: you want to identify areas that have elevation >= 600 meters & have a slope >= 30% 1. 2. 3. 1. • • "eggleston" >= 600 "Slope" >= 30 "Above600m" & "slopeabove30“ OR ("eggleston" >= 600) & ("Slope" >= 30) 2 separate queries for each criteria & then combine boolean outputs 1 compound query for both criteria EXERCISES • Already performed vector based spatial analysis on Day 2 during Rodney’s Multi-Criteria Evaluation • GIS Tutorial 2 Spatial Analysis – – – – – Tutorial 3-1 pg. 76 Tutorial 3-3 pg. 93 Tutorial 5-1 pg. 124 Tutorial 5-8 pg. 179 Tutorial 5-9 pg. 191 • MCE with Spatial Analyst (Auxiliary Materials notebook, Section 6)