Explanation of the criteria for classification and numbering of components     GO6.3.04
(NOV 99)
Explanation of the dates on the component's description



1.   Purpose and objectives

     HYMOS is a state-of-the-art information system developed for water resources authorities, water boards, hydrometeorological services and other organizations with responsibilities in monitoring and information management.

2.   Description

     HYMOS is comprehensive, well tuned and easy to use. The graphical and map-based user interface offers a pleasant and efficient working environment. The system facilitates processing of a wide range of water- related data. Fields of application include surface and groundwater hydrology; meteorology; water quality and ecology; and water resources management.

     The HYMOS database is time series oriented with common facilities for spatial analysis. Exchange of data between HYMOS and most GISs is easy and user friendly.

     Validation and completion- HYMOS offers a wide range of tabular, graphical, computational and statistical validation techniques among which: tabulation of series and flagging of outliers; plotting of time series; relation curves and double mass analysis; near-neighbour checks and series 
homogeneity tests.

     Various options are available for series completion. Among these are interpolation techniques that use series relations derived with regression techniques or spatial relations. Much emphasis has been given to facilities for administration of the data processing steps and data qualification features. The latter include assignment of labels to individual data indicating the source (for example original or corrected) and reliability of data.

     Analysis of meteorological data - Meteorological data like rainfall, snow depth, wind speed and radiation can be processed with HYMOS. Typical analyses are the computation of catchment rainfall (for example based on Thiessen polygons) and evapotranspiration using a range of methods including Penman with or without FAO-correction, pan evaporation, Christiansen, radiation, Makkink, Jensen-Haise, Blaney-Criddle and the mass transfer method.

     Flow measurements and stage-discharge analysis - The stage-discharge analysis options include the elaboration and validation of current metering data, the computation and validation of discharge rating curves and the extension of rating curves.  Rating curves can be represented by parabolic 
or power type equations, with up to three different water level ranges at a time. The Jones correction for unsteady flow can be applied and a procedure for effectively eliminating backwater effects while modelling the rating curve is available. Water levels are converted into discharges based on rating curves or (pre-programmed and user defined) structure equations.

     Rainfall-runoff simulation - HYMOS includes the Sacramento rainfall-runoff model, which is a well known and widely used conceptual hydrological model. Other hydrological, hydrodynamic or environmental models can be easily linked to the system when required.

     Statistical and time series analysis - A statistical package is available covering: computation of basic statistical parameters; fitting distributions including normal, log-normal, various Pearson types, log-Pearson, Raleigh, exponential, various Goodrich extreme types, Pareto and P.O.T.; data generation; correlogram and spectral analysis; range and run analysis; computation of frequency and duration curves; polynomial, multiple and step-wise regression analysis; time series analysis, e.g. 
cross and autocorrelation and spectrum.

3.   Input

     The HYMOS data editor allows user-friendly entry and editing of data. Monitoring network information and time series data can be entered manually, exchanged with spreadsheets and databases by using the clipboard or imported from file.  Data from recording monitoring stations can be 
downloaded automatically.

4.   Output

     HYMOS has a powerful graph server and standard templates for the graphical output of all analysis modules. The flexible graph server allows the user to easily tailor graph layouts to individual requirements. A wide range of formatted tables can be generated by HYMOS for presentation in 
annual reports. For final editing - when required - the output graphs and reports can be easily transferred to other WINDOWS programs.

5.   Operational requirements and restrictions

     HYMOS runs on stand-alone computers as well as in a network System. HYMOS is designed for the WINDOWS 95 and WINDOWS NT operating systems. The minimum computer configuration is a 32 Mb RAM and a 90 MHz Pentium processor.

6.   Form of presentation

     HYMOS is available on CD or 3.5 inch diskettes and supplied with a comprehensive User Guide and Tutorial in English.

7.   Operational experience

     HYMOS is used worldwide in over 30 countries by water authorities, consultants, research institutes and universities. Feedback from users all over the world during the more than 20 years of its existence has allowed for development of HYMOS into an efficient, flexible and multi-functional 
information system.

8.   Originator and technical support

     WL / DELFT HYDRAULICS: P.O. Box 177, 2600 MH Delft, The Netherlands
     Tel.: 015-2858585; fax 015-2858582; Homepage: WWW.WLDELFT.NL

9.   Availability

     From the HOMS National Reference Centre for The Netherlands. 

10.  Conditions on use

     The use of HYMOS is subject to a License Agreement at commercial rates. Discounts are available for purely educational use.

(First entered:17 MAY 93

Last updated: 13 AUG 99)