The i-Tree Sample Inventory Generator was designed to facilitate sample inventories for UFORE, STRATUM, and Storm Damage Assessment Protocol projects. For these applications, stringent protocols can make drawing samples a complex and time-consuming procedure. The Sample Inventory Generator automates the process through the use of a Geographic Information System (GIS), allowing any community to setup a statistically valid and compatible sample inventory with minimal expertise and effort.

The Sample Inventory Generator has two components: 1) a Sample Plot Generator for use with UFORE projects, and 2) a Street Segment Generator for use with STRATUM and Storm Damage Assessment Protocol projects.

Sample Plot Generator for UFORE

The Sample Plot Generator creates a sample inventory of plots for UFORE projects. Plot size and number are user-determined by means of suggested guidelines for efficiency and accuracy within different community profiles. Typically, 200 plots, each one-tenth acre in size, will produce about a 10% standard error for the total number of trees in large cities. Small towns have found success using a similar plot size, but with a sample of only 30 plots. Users import a city land-use map and run the plot generator using ESRI's ArcGIS software on their Desktop PC. Maps and location information, including geographic positioning system (GPS) coordinates, can be produced to help field crews locate sample plots on the ground.

Sample Street Segment Generator for STRATUM & Storm Damage Assessment Protocol Utility

The Sample Street Segment Generator creates a sample inventory of street segments for STRATUM and Storm Damage Assessment Protocol projects. The Sample Street Segment Generator is based on access and utilization of the TIGER database developed by the U.S. Census Bureau and provides users with a randomly drawn sample of street segments for inventory. Sampling intensity is determined by the user using suggested guidelines for efficiency and accuracy within different community profiles. Generally, a 3-6% sample of street segments, depending on community size and variation from plot to plot, will produce about a 10% standard error for the total number of trees. Smaller communities and towns have used sampling intensities at the 6% level, while large cities have used 3% samples. Users run the Utility using ESRI's ArcGIS software on their Desktop PC. Maps and location information can be produced to help field crews locate sample plots on the ground.