Explanation of the criteria for classification and numbering of components     G06.2.01
(JUL 99)
Explanation of the dates on the component's description



1.   Purpose and objectives

     To store hydrological data, to allow input from digitisers and data loggers (manually and from other software), to allow editing and presentation of the data, to allow retrieval in any required form, and to 
enable simulations to check and analyse the data.

2.   Description

     TIDEDA is computer software for processing TIme DEpendent DAta, particularly hydrological data. It stores time series of field measurements such as water level, rainfall, temperature, hydraulic gate 
setting, turbine output, wind vector components, or sediment concentration. Time is stored with each data point. Removal of redundant values that can be recovered by interpolation ("compression") saves storage space.  Storage of the original data series enables retrieval of flood hydrographs and 
flood maxima as well as daily, weekly, and monthly means.

     A set of rating curves describing a relationship that changes with time may be stored with the data and may be revised as new measurements come to hand.

     TIDEDA has its own programming language which enables the user to write software to analyse data as required. For example, a synthetic record may be generated to show how hydro-electric power generation or irrigation will change the flow regime in a river.

     TIDEDA is designed for high speed data retrieval and operates on personal computers in DOS and Windows environments.

3.   Input

     Original field records of water level, rainfall, etc; measurements of discharge, sediment  concentration, gate settings etc; rating curves relating two or more of these variables; language to control processing, editing, archiving and simulation; on-screen graphics editing.

4.   Output

     Data are stored on magnetic disks, or CD-ROM and may be produced in machine readable form for other programs such as spreadsheets. Displays on a printer or screen include calendar tabulations of averages or totals for days, weeks, months, or years; tabulations or plots of value versus fraction of time exceeded; plots of one time series against another; mass curves and similar analytical aids for simulation results. Graph plotter output includes hydrographs with the option of marking calibration 
measurements and rating curves with the same option.

5.   Operational requirements and restrictions

     TIDEDA is available on a number of computer operating systems. These include: MS-DOS and Windows, Vax VMS, Solaris, SCO Unix, Data General Aviion.

6.   Form of presentation

     Manual in English and compiled programs on diskette or tape. The software occupies 1.5 to 2 Mb of disk space.

7.   Operational experience

     TIDEDA has been the basis of the New Zealand national hydrological data archive since 1972. It has been used by 14 geographically dispersed hydrological field parties since 1983. It is also used by regional agencies throughout New Zealand, and in Papua New Guinea, Solomon Islands, Fiji, 
Vanuatu, Myanmar, Vietnam, Bangladesh, Nepal and Malaysia.

8.   Originator and technical support

     National Institute of Water and Atmospheric Research Ltd, P.O. Box 8602, Christchurch.

9.   Availability

     From the HOMS National Reference Centre for New Zealand.

10.  Conditions on use

     The system is copyright and is for sale. Prices are available on request from the HNRC.

(First entered:13 NOV 84

Last updated: 16 JUL 99)