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Thomas R. Payne & Associates is now part of the employee owned Normandeau Associates team.  We are the same professional staff with the expanded resources of a nationally recognized company providing high quality, practical environmental solutions.  Visit our Normandeau website also.

Fisheries Biology, Consulting and Software Publishing
890 L Street, Arcata, California USA 95521
P.O. Box 4678, Arcata, California USA 95518
(707) 822-8478


"I was so pleased about RHABSIM because it reduces sensibly the time necessary to build a physical habitat simulation model" - Paola Annoni, Milan, Italy

"RHABSIM was obviously designed by a serious IFIM user to facilitate PHABSIM assessments. The program brings a new era of ease of use to aquatic habitat modeling" - Dr. Stacy Li, Loomis, California

"We are really pleased with RHABSIM. The program is working extremely well and represents a major improvement over PHABSIM." - Barry Nehring, Montrose, Colorado

"The graphical outputs of RHABSIM are exceptionally valuable to me as an instructor...The toolbar scrolling by section, flow, HSI parameter or curve set is an excellent enhancement to rapidly make comparisons. That aspect alone will be a great teching tool, allowing students to make instant sensitivity analysis comparisons. The top [plan] view of colour-coded cells for the entire reach also illustrated variances between pools, riffles, runs and chutes in my study reach...

" excellent job of into a functional application not only for fisheries habitat management but for teaching instream flow assessment methodologies as well. My only remaining regret is that I didn't have RHABSIM six months ago when compiling my report..."
- Brian Meller, Lethbridge, Alberta

"When I began to use RHABSIM five years ago, I was pleasurably surprised when discovering the existence of that useful tool that allowed an easy PHABSIM simulation and an exhaustive IFIM analysis following all of its phases. Since then, we use RHABSIM for IFIM instream flow studies, not only for research but for teaching. RHABSIM is characterized by its simple, logical and practical handling in all its modules. The excellent graphics and reports facilitate the analysis and make of RHABSIM a great tool. What makes RHABSIM unique is that their modules can satisfy the necessities for an expert in hydraulics and a hydrologist (with HYDSIM and TIMESER, respectively) and for a hydrobiologist (with HABSIM+TIMESER jointly). From the hydraulic point of view, RHABSIM is really powerful and I am sure that it will satisfy the most demanding hydraulic's necessities related with hydraulic simulations in stable channels. I frequently also use exclusively RHABSIM to carry out hydraulic simulations for steady flow in streams, obviating the rest of the modules. The PHABSIM simulation with RHABSIM is very comfortable since those methods and parameters are selected easily. The possibility to compare several simulations simultaneously are a great improvement. And a very remarkable issue: RHABSIM is the only program that I know that goes beyond a mere PHABSIM analysis and completes all the phases of IFIM." - Juan Manuel Díez Hernández, University of Valladolid, Spain (e-mail:

"RHABSIM is a major facelift for PHABSIM II ... RHABSIM maintains the logical flow and computations for hydraulic calibration and habitat suitability models that are part of PHABSIM II. So what's new and different? The interface with the user contains what we've come to expect from user-friendly software, that is, pull-down menu bars, graphical output displays, and on-line help menus...program enhancements make hydraulic simulation much simpler with RHABSIM...RHABSIM makes it easier for users to graphically display their data, edit entries, and locate errors without resorting to painful review of paper outputs...

"I reviewed RHABSIM Version 1.17 for DOS...I approached the task with considerable procrastination, well aware of the learning curve for the complex series of modeling programs in PHABSIM. However, I was pleasantly surprised by the programming design that made accomplishing routine tasks more pleasant...

"The screen format served as a wonderful reminder of where I was in the modeling process--a must for anyone disturbed by frequent interruptions. The menu bar provides access to drop-down menus and submenus. Process outlines are a part of each main program module. These answer the "what do I do next?" questions that plague all users...

"The experienced PHABSIM user will find that this program has a very short learning curve. The variety of graphical displays were very useful during the error-checking and model calibration phases...

"RHABSIM is a good tool that makes these modeling techniques easier to learn. Existing PHABSIM users will find that the transition to RHABSIM is very easy and well worth the switch. "
- Donald J. Orth, Blacksburg, Virginia

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