WORLD METEOROLOGICAL ORGANIZATION                            HOMS COMPONENT
                                                                   I81.2.02
                                                                   (AUG 90)

             THE CONSOLIDATED FREQUENCY ANALYSIS (CFA) PACKAGE

1.   PURPOSE AND OBJECTIVES
     To provide a user-friendly interactive computer package to analyze the
data with respect to the underlying assumptions of flood frequency analysis
and to perform flood frequency analyses using several frequency
distributions.

2.   DESCRIPTION
     The CFA Package allows the user to:  easily enter flood data for
analysis; modify data sets so as to add, delete, or modify all stored
information; save modified data sets for future use; perform nonparametric
tests for homogeneity, trend, independence and randomness; graphically
display data in various fashions; perform tests for low and high outliers;
determine T-year events for the straightforward case, samples with historic
information, samples with low outliers, samples with zero flow values, and
combinations of these.  The probability distributions available are:

         1)  generalized extreme value;
         2)  three-parameter lognormal;
         3)  Log Pearson Type III; and
         4)  Wakeby.

3.   INPUT
     Annual maximum daily or instantaneous discharge and the year and month
of its occurrence constitute the data required for analysis.

     The censoring threshold and the number of floods where exact
magnitudes are not known but which are known to have occurred and are less
than the threshold can be included so that an historical flood frequency
analysis can be performed.  Data and historic information can be entered
via the keyboard or read from mass storage devices.

4.   OUTPUT
     Results of nonparametric tests for homogeneity, trend, independence
and randomness.  Graphical displays of the data are also available as a
visual aid in the assessment of the data regarding the assumptions of
frequency analysis.  Once a sample passes the screening procedure, a
frequency analysis may be performed.  Summary statistics in real and log
(Naperian) formats are given for the flood data.  Parameters of selected
distributions, tables of design flood estimates, and frequency curves are
available.

5.   OPERATIONAL REQUIREMENTS AND RESTRICTIONS
     The current version of CFA software was written in Fortran 77 to run under DOS 3.1 on IBM-type microcomputers with a math coprocessor.  However, it can also be used on computers running Windows 95 and 98. 

     CFA was designed to be user friendly and interactive, thus no
knowledge of programming is required to operate the package.
Interpretation of results should be performed by analysts having knowledge
of the assumptions and limitations of the approaches, mathematical
treatment, and implications regarding the selection of design floods.

6.   FORM OF PRESENTATION
     The user manual and appendices are in English.  Diskettes contain an
executable module and a sample data set.  

7.   OPERATIONAL EXPERIENCE
     CFA has been applied to several hundred hydrometric sites in Canada
and is currently widely used by government agencies and private industry.
In addition, CFA has been distributed to individuals in over 15 countries.

8.   ORIGINATOR AND TECHNICAL SUPPORT
     Atmospheric Environment Service, Environment Canada.  Technical
support can be provided in both French and English by Greenland International Consulting Inc. (http://www.grnland.com) and Environment Canada.

9.  AVAILABILITY
     Through the  HOMS National Reference Centre for Canada
 or directly from Greenland International Consulting Inc. via the Internet (http://www.grnland.com/sftware/Software.htm) or by phone (905) 738-1818 

10.  CONDITIONS ON USE
     Licences for CFA must be purchased from Greenland International Consulting Inc.  Educational and multiple licence discounts are available.

(First entered :  24 AUG 90                      Last updated :  14 DEC 1999)

