Northeastern Forest Inventory and Analysis

Northeastern Forest Inventory & Analysis


Introduction Flowchart of Process Outline of Steps Definitions and Descriptions Discussion Step by Step Examples & Downloads Videos Arc Scripts Contact: Andrew Lister

	Forest Inventory & Analysis Program 11 Campus Blvd. Suite 200 Newtown Square, PA 19073-3294 (610)557-4075 (610)557-4250 FAX (610)557-4132 TTY/TDD

GIS /Spatial Statistics

Geostatistics Workshop

Flow Chart of General Process

	Gather data / Data prep	Select data for analysis View data spatially Prepare data for normal-scoring Put data into proper formats for software

	Examine the data	Check data for errors Examine data characteristics

	Modeling the Variograms:	of the normal-scored data for the SGCS of the original data for OK and MWA of the original data with a cutoff for IK

OK or MWA	SGCS	IK
(ordinary kriging) or Moving Windows Average --simpler methods when all you need is a quick look...	(sequential gaussian conditional simulation) --for creating the standard species distribution maps	(indicator kriging) --for creating the 'probability of occurrence' maps

Choosing the parameters	Choosing the parameters	Choosing the parameters

Running the kriging	Running the simulation	Running the kriging

Calculating a measure of uncertainty	Calculating summary stats from the 100 realizations

	Choice of summary stat to use as the 'estimate' and the 'uncertainty'

	Accuracy Assessment	Checking for bias in the algorithm Checking for reproduction of original data Characteristics of interest Checking against original data values

	Presentation--map creation and Distribution (putting on the web)	Presentation: of the estimates, the uncertainty, and the results of the accuracy assessment Distribution: of output maps, datasets, and metadata/documentation

	Documentation/Metadata:	of the models used, the parameters used, the data used, etc...