FragStats

Page created by Leandro Gonzalez

Description

FRAGSTATS is a computer software able to calculate a large variety of landscape metrics for categorical map patterns. The original version of FRAGSTATS software was developed by Dr. McGarigal and Barbara Marks of Oregon State University. Currently, there are three different versions of FragStats’ software. The first version (Version 2) was produced in 1995 in association with the publication of a USDA Forest Service General Technical Report. The second version was released in 2002 (version 3). This version, along with version 4, can accommodate ArcGIS10 data. The latest release (version 4) shows a completely new interface intended to support the addition of cell-level metrics and surface pattern metrics. Version 4 has essentially the same functionality as version 3. Software versions 3 and 4 can be downloaded for free from Downloads. A new version, FragStats 4.1, is scheduled to be released later in 2012.
FRAGSTATS calculates a variety of statistics for every patch and class (patch type) in the landscape as well as for the total area of the landscape. At the class and landscape level, some metrics quantify landscape composition, while others quantify landscape configuration. The composition and configuration of a landscape can influence ecological processes. Therefore, it is relevant to comprehend what aspect of landscape pattern is being quantified by each metric. FragStats groups metrics according to the aspect of landscape pattern and are measured as follows:

  • Area and edge metrics
  • Shape metrics
  • Core area metrics
  • Contrast metrics
  • Aggregation metrics
  • Diversity metrics

Software/Hardware Specifications

FRAGSTATS 4.0 was written in Microsoft Visual C++ for use in the Windows operating environment and is a 32-bit process (even if running on a 64-bit machine). Since FRAGSTATS 4.0 was developed in a Microsoft environment, its portability to other platforms is not easily accomplished. FRAGSTATS 4.0 is a 32-bit software, meaning that normally it can only use a maximum of 2GB of memory. However, if adequately configured, Windows can allow a 32-bit process to use up to 3GB of memory. FRAGSTATS 4.0 loads the input grid (See input file formats) into memory and then computes all requested calculations. Thus, users must have sufficient memory to load the grid and then enough leftover for processing and other operating system needs.

Installing the Software

FRAGSTATS 4.0 installation is quick and easy. After downloading the zip file from Downloads, simply extract the file to a folder of your preference, double click on the frg_setup_4.0.exe file and follow the instructions. To complete the installation you may need to disable your virus protection software, or at least disable the disk access protection. Once installed, FRAGSTATS 4.0 is run by double clicking on the frg_gui.exe file or selecting it from the start menu or desktop.

Input File Formats

FRAGSTATS 4.0 accepts raster images in a variety of formats, including ArcGrid 10 (or earlier), raw ASCII, and raw 8-, 16-, and 32-bit BINARY. FRAGSTATS 4.0 does not accept Arc/Info vector coverages. Coverages are the oldest type of vector files developed by ESRI. Currently most vector files are either shapefiles or feature classes. FRAGSTATS accepts shapefiles and feautre classes.

Output

Depending on which metrics are selected by the user, FRAGSTATS 4.0 creates 4 output files corresponding to the three levels of metrics and the adjacency matrix.

The user selects a “basename” for the output files and FRAGSTATS 4.0 appends the extensions: .patch, .class, .land, and .adj to the selected basename. All files created are comma-delimited ASCII files and viewable. These files are formatted to facilitate input into spreadsheets and database management programs:

“basename”.patch file.–Contains the patch metrics; the file contains 1 record (row) for each patch in the landscape; columns represent the selected patch metrics. If a batch file is analyzed, the file contains 1 record for each patch in each landscape specified in the batch file. The first record is a column header consisting of the acronyms for all the metrics that follow.

“basename”.class file.–Contains the class metrics; the file contains 1 record (row) for each class in the landscape; columns represent the selected class metrics. If a batch file is analyzed, the file contains 1 record for each class in each landscape specified in the batch file. The first record is a column header consisting of the acronyms for all the metrics that follow.

“basename”.land file.–Contains the landscape metrics; the file contains 1 record (row) for the landscape; columns represent the selected landscape metrics. If a batch file is analyzed, the file contains 1 record for each landscape specified in the batch file. The first record is a column header consisting of the acronyms for all the metrics that follow.

“basename”.adj file.–Contains the class adjacency matrix; the file contains a simple header in addition to 1 record (row) for each class in the landscape, and is given in the form of a 2-way matrix. Specifically, first record contains the input file name, including the full path. The second record and first column contain the class IDs (i.e., the grid integer values associated with each class), and the elements of the matrix are the tallies of cell adjacencies for each pairwise combination of classes.

Rangeland Use Examples

Ruiz-Miraso et al. 2012, studied relationships between landscape structure and the pastoral wildfires recorded between 1988 and 2000 in 24 Nature Park landscapes in Andalusia (Spain).

Kadiogullari and Baskent 2008, analyzed spatial and temporal changes in land use and land cover patterns in a typical mountain watershed in the Gumushane district along the Northeastern part of Turkey.

Kamusoko and Aniya 2007, analyzed the dynamics of land use/cover and land degradation as revealed in landscape fragmentation in the Bindura District of Zimbabwe based on Landsat data for 1973 and 2000.

Rangeland Studies References

Kadigullari AI. and Baskent EZ. 2008. Spatial and temporal dynamics of land use pattern in Eastern Turkey: a case study in Gumushane. In ENVIRONMENTAL MONITORING AND ASSESSMENT. 138(1-3): 289-303.

Kamusoko C. and Aniya M. 2007. Land use/cover change and landscape fragmentation analysis in the Bindura District, Zimbabwe. In Land Degradation and Development. 18(2): 221-233.

Ruiz-Mirazo J., Martinez-Fernandez J., Vega-Garcia, C. 2012. Pastoral wildfires in the Mediterranean: Understanding their linkages to land cover patterns in managed landscapes. In Journal of Environmental Management. 98: 43-50.

Additional Information

• FRAGSTATS Documentation — This page contains links to all FRAGSTATS documentation, including slide presentations from prior workshops.

• Downloads — This page is where you go to download the software and documentation.

• FAQ — This page contains answers to frequently asked questions, including questions and answers extracted from the FRAGSTATS list serve that warrant permanent posting.

• Links — This page contains links to other web sites containing information on related software.

• Workshops — This page contains links to workshop materials for any upcoming scheduled workshop.

Technical References

Landscape Ecology Lab. 2012. University of Massachusetts (Amherst). On [WWW] at http://www.umass.edu/landeco/research/fragstats/fragstats.html

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