Water Resources Applications Software
Summary of WDM
NAME
wdm - Watershed Data Management file system
ABSTRACT
The Watershed Data Management (WDM) system provides a systematic
approach to the storage and retrieval of data required to operate
hydrologic, hydraulic, and water-quality models. The WDM system
uses a well-defined binary, direct-access file structure accessed
through a library of routines to create a file, add data to the
file, replace data in the file, get data from the file and delete
data from the file. Five categories of data may be stored in WDM
file data sets: time series, tables, text, vectors, and space-time.
A comprehensive set of attributes is available for documenting and
describing individual data sets.
The WDM library of routines enables expedient input, update, and
output of data. WDM files allow comprehensive specification of data
attributes, multiple time steps in single time-series data sets,
user-defined formats for data stored as tables, compression of data,
improved speed and flexibility of interaction between a model and
its data base, and automatic file maintenance as the user adds,
modifies, or deletes data sets. The WDM system allows multiple
models, requiring different data types and data with different time
steps, to use a common data base.
The WDM library is included in the LIB distribution. It requires
the UTIL and ADWDM libraries from the LIB distribution.
METHOD
A WDM file is a binary, direct-access file used to store hydrologic,
hydraulic, meteorologic, water-quality, and physiographic data. The
WDM file is organized into data sets. Each data set contains a
specific type of data, such as streamflow at a specific site or air
temperature at a weather station. Each data set contains attributes
that describe the data, such as station identification number, time
step of data, latitude, and longitude. A WDM file may contain a
single data set or as many as 200,000 data sets. A data set may be
described by a few attributes or by hundreds of attributes. Data
can be added, deleted, and modified without restructuring the data
in the file. Space from deleted data sets is reused.
HISTORY
The original design and implementation of time-series data sets in
the WDM file was a cooperative effort between the USGS and the Soil
Conservation Service in 1983. The USGS and EPA have implemented the
tables, text, vectors, and space-time data sets since then.
Originally implemented on Prime and Vax minicomputers and MS-DOS
compatible personal computers (1983-1991).
Version 3.1 1996/12/11 - Added new subroutine WDBSGL to retrieve
latitude and longitude from a data set.
Version 3.0 1996/03/01 - Include file names changed to lower case.
Corrected the valid minimum for attribute JANMIN (changed from
0.0 to no lower limit).
Version 2.1 1994/08/11 - Updates
Version 2.0 1994/05/27 - General release
Version 1.0 1992 - General release, ported to UNIX platform.
NOTE: Version numbers and dates are for the entire lib set of
libraries. A new version does not necessarily indicate that
the WDM library has been changed.
SYSTEM REQUIREMENTS
WDM is written in Fortran 77 with the following extension: use of
include files. The WDM library requires the ADWDM and UTIL
libraries.
APPLICATIONS
The WDM file was initially created for use by the program ANNIE for
storage, manipulation, graphical display, and statistical analysis
of watershed data. With the implementation of other programs
capable of accessing data stored in WDM files, each WDM file serves
as a common data base from which data are shared among multiple
applications and across different computer platforms. Examples of
programs using WDM files include DR3M, HSPF, PRMS, and SWSTAT, which
performs the statistical analyses previously found in ANNIE.
DOCUMENTATION
A subroutine reference guide is provided with the distribution.
Lumb, A.M., Carsel, R.F., and Kittle, J.L., Jr., 1988, Data
management for water-quality modeling development and use:
Proceedings of the International Conference on Interactive
Information and Processing Systems for Meteorology, Oceanography,
and Hydrology.
REFERENCES
Flynn, K.M., Hummel, P.R., Lumb, A.M., and Kittle, J.L., Jr., 1995,
User's manual for ANNIE, version 2, a computer program for
interactive hydrologic data management: U.S. Geological Survey
Water-Resources Investigations Report 95-4085, 211 p.
Landers, M.N., Mueller, D.S., and Martin, G.R., 1996, Bridge scour
data management system user's manual: U.S. Geological Survey
Open-File Report 95-754, 72 p.
Lumb, A.M., McCammon, R.B., and Kittle, J.L., Jr., 1994, Users
manual for an expert system (HSPEXP) for calibration of the
Hydrologic Simulation Program--Fortran: U.S. Geological Survey
Water-Resources Investigations Report 94-4168, 102 p.
CONTACTS
Operation and Distribution:
U.S. Geological Survey
Hydrologic Analysis Software Support Program
437 National Center
Reston, VA 20192
h2osoft@usgs.gov
Official versions of U.S. Geological Survey water-resources analysis
software are available for electronic retrieval via the World Wide
Web (WWW) at:
http://water.usgs.gov/software/
and via anonymous File Transfer Protocol (FTP) from:
water.usgs.gov (path: /pub/software).
The WWW page and anonymous FTP directory from which the LIB software
can be retrieved are, respectively:
http://water.usgs.gov/software/lib.html
--and--
/pub/software/general/lib
The URL for this page is: http://water.usgs.gov/cgi-bin/man_wrdapp?wdm
Send questions or comments to h2osoft@usgs.gov