The BROOK90 Hydrologic Model

[Last revised - February 2, 2011]

The continued world-wide use of BROOK90 has been very gratifying and has inspired me to revise its web site and documentation.

LINKS

Published Papers Using BROOK90   Aug 19, 2010

BROOK90 Documentation on the web   Nov 17, 2010

BROOK90 Version 4 Updates   Nov 17, 2010

BROOK90 Version 3 Updates   Sep 8, 2010

DOWNLOADS

BROOK90 Version 4.4g

Nov 17, 2010		 BROOK90 Data Files

Nov 17, 2010		 BROOK90 Documentation

Nov 17, 2010		 msvbm60.dll

6.0.98.2		 comdlg32.ocx

6.1.98.13		 BROOK90 Source Code (optional)

Nov17, 2010

INTRODUCTION

BROOK90 is a parameter-rich spatially-lumped hydrologic model designed to study the processes of evapotranspiration and soil water movement at a point, with some provision for streamflow generation by different flow paths (see flow chart). It is a major modification of the simpler and older BROOK2 hydrologic model. BROOK90 simulates the water budget on a unit land area at a daily time step and is applicable to all land surfaces. Input of daily precipitation and maximum and minimum temperatures is required, and daily solar radiation, vapor pressure, and wind speed are desirable. The model estimates interception and transpiration from a single layer (big leaf) plant canopy, soil and snow evaporation, snow accumulation and melt, and soil-water movement through one or more soil layers (including macropore-assisted infiltration). Stormflow is generated by a variable source area or simple pipe flow. Delayed flow is from soil drainage and a first-order groundwater storage. BROOK90 uses a Shuttleworth-Wallace modification to Penman-Monteith potential evaporation in order to separate transpiration and soil evaporation from sparse canopies. Actual transpiration is reduced below potential using Federer's method based on root density with depth, plant resistance, and a critical leaf-water potential. Water movement between soil layers is integrated using Darcy's Law and variable time-steps.

BROOK90 is a one-person project. Early versions were written by me, C. Anthony Federer, when I was a scientist with the U.S. Forest Service. Windows-based versions and these web pages are the product of my retirement under my "business" name, Compass Brook. Please email me at if you have any questions about BROOK90.

DOCUMENTATION

The primary documentation for BROOK90 is written in HTML 4 (Transitional) and contains many cross-links. It can be viewed online or downloaded through the links above. The downloaded documentation can be unzipped into any folder. It can be printed from any browser, but, of course, loses the links.

NOTE: Both the model and the documentation have changed over time. New users should obtain the latest version of both documentation and model here. Old users should check the BROOK90 Version 4 Updates page to see whether more recent modifications are relevant.

A suggested citation for the model is:
"Federer, C.A. 2002. BROOK 90: A simulation model for evaporation, soil water, and streamflow. http://www.ecoshift.net."

For a more general citation, use the only refereed publication I have produced with BROOK90:
"Federer, C.A., C. Vörösmarty, and B. Fekete. 2003. Sensitivity of annual evaporation to soil and root properties in two models of contrasting complexity. J Hydrometeorology 4:1276-1290."

The BROOK90 Publications page lists many of the publications that have used BROOK90.

The second edition of "Physical Hydrology" by S. L. Dingman (Prentice Hall, New Jersey, USA) uses BROOK90 to illustrate hydrologic modeling and gives BROOK90 algorithms for some processes. Readers should note that the KKMEAN equation on page 264 has been changed in later versions of BROOK90 to eliminate the weighting for layer thicknesses (THICK).

VERSIONS OF BROOK90

A number of different versions of BROOK90 exist around the world. As of September 2010 I am removing all software for versions prior to Version 4.4c from this web site and from documentation, except on the BROOK90 Version 4 Updates and BROOK90 Version 3 Updates pages. Users of earlier versions presumably have the documentation that goes with them.

Versions prior to 4.4c will give different results in some cases because the soil water flow algorithm has changed. Canopy and Fixed parameter files from versions prior to 4.3 will not work in later versions. See BROOK90 Version 4 Updates for more information.

Since Version 4.1, BROOK90 is a 32-bit program written in Visual Basic 6 and developed in Windows95. It runs in Windows XP, which is my current OS, and should run in Vista and later.

Version 3.2/3.3/3.4 is a 16-bit program written in Visual Basic 3 for Windows 3.1x/95/98/NT only. The last release is Version 3.4a dated December 20, 2002. Version 3.1Q is in QuickBasic for DOS and Version 3.1F is in Fortran-77. Version 3 data and parameter files cannot be used in Version 4. See Version 3 Updates if you are a Version 3 user.

Version LWF-BROOK90 is a modification of Version 3.1F by Martin Kennel and his colleagues in Germany. It contains a front end with graphics output, vanGenuchten soil parameterization, stand development over time, and temperature-dependent phenology. Documentation is Hammel, K. and M. Kennel. 2001. Charakterisierung und Analyse der Wasserverfügbarkeit und des Wasserhaushalts von Waldstandorten in Bayern mit dem Simulationsmodell BROOK90. Forstliche Forschungsberichte München 185.

Versions 1 and 2 of BROOK90 are obsolete partial models; they should be discarded.

RUNNING BROOK90

BROOK90 must be installed manually, so you know just what files are going where. It does not use the Windows registry. The Compass Brook computer is virus-protected by ZoneAlarm Security Suite.

Download b90v44.zip and b90v44data.zip from the links above and unzip them into any folder.

Two additional files also need to be present. The file msvbm60.dll (Visual Basic 6) apparently is included in all versions of Windows so far. However, comdlg32.ocx (Windows Common Dialog) has not been included in recent Windows versions and should be downloaded from above. In 32-bit Windows these two files should be in the C:\Windows\System\ folder. In 64-bit versions, they should be in c:\Windows\SysWOW64\; then if BROOK90 still fails to run, you should run

regsvr32 c:\Windows\SysWOW64\comdlg32.ocx
with administrator privileges to register it.

Users wishing to modify BROOK90 can also download the VB source code. The algorithm routines should be easily translatable for other compilers, but the Windows GUI is very tricky to modify.

To make a test run:

To learn about BROOK90:

BROOK90 Version 4 reads daily input from a data file as it runs. Data files must be produced or modified by using a text editor such asTextPad, which allows column moves, or by using a spreadsheet program like Excel to produce a .CSV file.

BROOK90 optionally allows for precipitation input at intervals less than once a day. When used, this data is read from a separate precip interval file.

BROOK90 Version 4 requires six separate parameter files: Location, Flow, Canopy, Soil, Fixed, and Initial files. Each contains a number of names and values that must be in correct order. These files can be created and edited either within BROOK90 (safer) or externally with a text editor. With some restrictions, these values and even the whole file can be changed within a model run.

Output values of a many variables may be produced at iteration, precip, daily, monthly, and annual intervals. Graphic output of precipitation, snow, soil water, evaporation, simulated streamflow, and measured streamflow (if input) over time can be displayed during a run.

The Windows version of BROOK90 was written to allow scripting for automatic multiple runs with data and parameter changes. I have used Fabsoft Shortcut for Windows to run BROOK90 in scripted batch mode; this can be found at download sites, but is no longer listed at fabsoft.com so it can not be paid for and will only run for a limited time. AutoHotKey is another possibility for writing BROOK90 scripts, but I have not tried it.

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