Habitat Equivalency Analysis Software to Facilitate Calculation of Compensatory Restoration following Natural Resource Injury
Habitat Equivalency Analysis (HEA) is a means to determine the amount of compensatory restoration required to provide services that are equivalent to the interim loss of natural resource services following injury. The lost services are calculated from the time of injury through the recovery process. Recovery could be either via natural recovery or active restoration. The compensatory restoration services are calculated from the time of commencement through process of the chosen restoration. An injury to natural resources therefore involves a time component during which the ecological services that the resources provide are lost and over which the services of any compensatory restoration are gained. HEA uses a discounting procedure to account for asset valuation in that the total asset value is equal to the present discounted value of the future stream of all services from the natural resource or the compensatory resource. This concept of discounting is explained by an individual's preference for goods and services at any given time. Discounting takes into account that the further into the future that a service is provided, the less it is valued today. Therefore, the HEA approach is particularly well suited for analysis because it can be used to quantify the loss and recovery of resources and includes this time factor.
Visual_HEA is a program that provides an efficient method of calculating the required compensation. The program accepts input of parameters necessary to determine long-term service loss from the injury (injured area size and degree; times of injury, functional shape, and equilibrium; post-injury recovery); parameters to determine long-term service gain from compensatory restoration actions (times of restoration beginning and equilibrium; maximum service level; service gain function shape); and general program parameters (relative value of lost and gained services, baseline level of lost and gained services, discount rate).
Because HEA results are highly dependent upon assumptions, it is useful to examine sensitivity of results using a range of parameter values. Visual_HEA facilitates comparisons by offering an intuitive graphical interface that allows the user to modify input parameters and quickly alter the lost and gain service level shape functions. The ability to formulate many scenarios provides an efficient method of gauging the sensitivity of the required compensatory action scale to the analysis parameterization and time variability.
We have developed an interactive program, Visual_HEA, that facilitates input of HEA assumptions and parameters and provides an efficient method of calculating the compensatory action required for a given injury site. The program allows input of the relevant parameters necessary for analysis, and through the use of an intuitive graphical interface, the input parameters and recovery shape functions can be quickly changed. The ability to formulate many "what-if" scenarios using the graphical interface provides an efficient method of gauging the sensitivity of the required compensatory action scale to the analysis parameterization and time variability.
The National Coral Reef Institute released minor version 2.61 of Visual HEA in October of 2014. This version includes bug fixes to the software and reformatting of the .pdf output file. Quarterly calculations have been enhanced and improvements made to the GUI to facilitate quarterly analysis. Version 2.61 is backward-compatible with previous versions.
In cooperation with the University of Montpellier, the National Coral Reef Institute has released version 2.6 of Visual HEA in August of 2012 which includes a full French translation and many enhancements and bug fixes. To comply with the Environmental Liability Law of 2006 and via the European Directive of 2008, the French government has recommended Visual HEA serve as the de facto standard software to be used when conducting habitat equivalency analysis.
Version 2.6 includes the following major enhancements and bug fixes:
- Full French translation
- Discount rate accuracy has been increased to 3 decimal places
- French version default discount rate has been set at 4% (the European standard)
- Output to a .pdf file has been added the postscript output has been discontinued
- An error in the calculation of quarterly SAY's gained has been fixed
- An error in calculating quarterly % services lost has been corrected
- A correction was made to calculate the entire last year when calculating quarterly gains
- Pre-injury and pre-service level decimal precision has been increased to 2 decimal places
- The ability to manually configure quarterly nodes has been added
Both the French and English version of Visual HEA 2.6 are available in the downloads section.
About Visual HEA
The Visual HEA program is being made available free of charge to the scientific community as copyrighted freeware and cannot be sold, modified, or re-distributed. You will be sent the download information via email after completing our Visual HEA Download Request Form.
Visual HEA is released as copyrighted freeware. It is Nova Southeastern University's National Coral Reef Institute's (NCRI) aim to provide a useful tool for researchers, coral reef managers, and individuals involved in coral reef monitoring, assessment, and restoration.
Sylvain P, Johnston MW, Vaissièrec AC, Bergerd F, Jacoba C, Dodge R (2017) An update of the Visual_HEA software to improve the implementation of the Habitat Equivalency Analysis method. Ecological Engineering 105, 276-283.
- Download the paper (998KB PDF)
Kohler, K.E. and R.E. Dodge (2006) Visual_HEA: Habitat Equivalency Analysis software to calculate compensatory restoration following natural resource injury. Proceedings of the 10th International Coral Reef Symposium. Okinawa, Japan. pp. 1611-1616.
- Download the paper (626KB PDF)
National Oceanic and Atmospheric Administration. 2000. Habitat Equivalency Analysis: An Overview. Washington, D.C. NOAA Milon, J.W. and R.E.Dodge. 2001. Applying Habitat Equivalency Analysis for Coral Reef Damage Assessment and Restoration. Bull. Mar. Sci., 69(2): 975–988. This work is a result of research funded by the National Oceanic and Atmospheric Administration Coastal Ocean Program under award #NA03NOS4260046 to Nova Southeastern University for the National Coral Reef Institute (NCRI).
Support Visual HEA Due to its popularity, updating Visual HEA and providing support via email and telephone requires a significant amount of time and effort. If you have found Visual HEA to be useful for your institution's research, we encourage you to make a donation that will be used for the further development and support of Visual HEA. You can make a donation by directly sending a check or by credit card. Please email "Visual HEA Donations" to firstname.lastname@example.org for details. Donation suggestions: Single user: $200 Multiple user (<10): $500 Multiple user (>10): $1000
Halmos College of Arts and Sciences, Department of Marine and Environmental Sciences
Nova Southeastern University, "Visual_HEA Software" (2023). NSU Software. 4.