Skip to main content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Invasive Species Risk Assessment

Invasive Species Sample Design Tool

The Invasive Species Sample Design Tool prioritizes the selection of sample locations for detection and survey activities based on pest risk. Sample location selection is conducted in ArcGIS 10.0 using the "Create Spatially Balanced Sample" tool which generates spatially balanced sample points based on the inclusion probability surface. The spatially balanced design improves sampling efficiency by maximizing the spatial independence of sample points, thereby providing the most information available per sample unit.

Benefits of the tool are that users may dynamically set the geographic area of interest and specify the number of sample locations to be selected. To create the sample points, the tool requires two inputs, 1) an inclusion probability raster, and 2) the number of output sample locations specified by the user. The tool then automates the selection of spatially balanced sample locations from a standardized 1 km grid for the contiguous U.S. using a risk based inclusion probability surface. By utilizing a surface with known inclusion probabilities, the tool provides an objective and transparent methodology for selecting sample locations.

Requirements: This tool assumes the user possesses a basic understanding of, and an appropriate skill set pertaining to ArcGIS, Arctoolbox, and general GIS concepts, and has had some experience working with raster and polygon data. The Sample Design Tool "User Manual" (included in the download below) provides detailed step by step instruction on how to utilize the tool. Required software:

  • ArcMap 10.0
  • SArcGIS 10.0 service pack 4 or higher

Sample Design Tool Download

Note: file size is large. Please be patient when downloading.

Invasive Species Sample Design Tool (771 MB ZIP)

Contents of the Sample Design Tool ZIP File:

  • ArcGIS Sample Design Tool Box
  • Sample Design Geodatabase containing the spatial datasets required for tool operation as well as an example inclusion probability raster
  • Sample Design Python Script
  • Invasive Species Sample Design Tool User Manual