| Introduction
Hydraccess is an extensive, homogenous and user friendly
software, which allows to import and manage various kind of
hydrological data in a Microsoft Access 2000
database, and to realize all processing that an Hydrologist
can need. It was developed by an hydrologist for other hydrologists.
Its development began in year 2000, and was regularly continued
since. Its author is Philippe Vauchel, Hydrologist in the
IRD (French Research Institute for Development), and the software
is a property of IRD.
Hydraccess exists in French,
Spanish,
and English.
It can be downloaded freely, denying responsibility of the
software author and IRD in case of malfunction.
Hydraccess will be interesting for students, engineers and
scientists who wish to archive, visualize and process their
hydrologic data. Hydraccess makes use of the well known MS
Office database (ACCESS) and spreadsheet (EXCEL).
Hydraccess makes an extensive use of Microsoft Office automation
possibilities. As a result of many functions, it creates Excel
workbooks (and sometimes Word documents for water yearbook
tables), allowing for the user to obtain data tables and elaborated
graphs, that can be customized and directly included in reports.
Hydraccess offers many possibilities to visualize data, in
simple or comparative graphs, that can be freely scrolled
in Excel, thanks to a little Excel macro that comes with the
software. So the user can visualize the data with a time step
convenient to the data variability.
Hydraccess is suited for data processing from micro watershed
to large rivers. For small catchment areas, functions to analyse
Rainfall – Discharge events and storm intensities
are available.
|
|
|
|
Figure 1 : Hydraccess menu sample.
|
|
Antecedents
Before becoming the IRD, ORSTOM had been in the early seventies
a pioneer of introducing computers in the field of hydrology,
and a good deal of hydrology oriented software had been developed.
The most famous surely were the HYDROM and
PLUVIOM packages (G. Cochonneau, P. Raous),
that many hydrological services in partnership with ORSTOM
have known and used in Africa and South America. We can also
mention the Regional Vector of rainfall indexes
method (Y. Brunet Moret, G. Hiez), different modules to adjust
probability laws, such as DixLois (Y. Brunet
Moret), and functions to digitize stage and
rainfall charts.
Hydraccess ambitions to be the follower of that tradition.
As a software developed by an IRD hydrologist, it is the natural
successor of HYDROM and PLUVIOM, which were a source of inspiration,
and would like to valorise as much as possible this past experience
of ORSTOM in the field of hydrology oriented software.
|
|
Data managed by
Hydraccess
Hydraccess can manage the following data:
- Chronological series: stages, discharges,
water quality, rainfall, meteorological data.
- Discharge measurements: discharge as
a function of stage, and cross-sectional SM (suspended materials)
as a function of surface SM.
- Rating curves: discharge as a function
of stage, cross-sectional SM as a function of surface SM,
solid discharge as a function of liquid discharge.
- Station reports: free text data related
to station history.
- Stage gauges general datums, in meters
above sea level.
Hydraccess can import data contained in Text
or Excel files, provided these files respect
an adequate format. In case of Diagram input files
(chronological data produced by a recorder), Hydraccess offers
a module allowing to visualize this diagram, and to perform
level or time corrections, before importing it in the database.
Time series data as stages, discharges, water quality data,
rainfall and meteorological data are organized in different
tables. They are linked to a station (a measurement
location) and to a sensor (the name of a
data series). The sensor has properties allowing to define
its description, unit, significant digits and decimals. There
are three types of sensors:
- Instantaneous sensors: data is entered
freely with a date and time, without any imposed time step.
Rainfall increments can be entered to the second, and other
data to the minute.
- Daily sensors: only one value per day
can be entered.
- Monthly sensors: only one value per
month can be entered.
In any case, it is possible to associate to each value:
- An origin code, which indicates if the
value comes from a staff measurement, a recorder, or a data
reconstitution.
- A quality code : Ok or doubtful value.
- For rainfall, a type code : rainfall,
snow, hail, dew or traces.
|
|
Basic processing functions
Basic functions of Hydraccess are:
- Various graphic functions producing
data, and simple or comparative graphs in Excel.
- Possibility of Stage – Discharge rating
curves for bi-unique and not bi-unique stations
(in this case, water level gradient or relative altitude
difference methods are proposed), and plotting of discharge
measurements on rating curve.
- Discharge and solid discharge
calculation, using the rating curves previously
defined.
- Digitisation and importation
of diagrams, with various editions facilities.
- Data aggregation on various time steps,
from one minute to one year, passing through one day, 5
days, 10 days, 15 days and one month.
- Production of water yearbook tables,
on a daily or monthly basis.
- Inventory of data existing in the database.
Hydraccess also contains advanced functions:
- Analisis of rainfall intensities, such
as effective and exceeding rainfall for some intensity thresholds,
maximum rainfall for a time interval, Wischmeier erosivity
indexes and Köhler indexes.
- Frequencies studies : fitting of probability
laws to samples of annual values, or to samples of values
passing a given threshold.
- Reconstitution of floods entering a small reservoir,
knowing the reservoir stage variation, the spilled discharges,
and rainfall above the reservoir.
- Interactive separation of rainfall and discharge
events, storm analysis, flood analysis, recession
analysis, and creation Excel graphs for of Rainfall
– Discharge events.
- Advanced functions for solid discharge calculation
with diverse methods.
- Classified and characteristic
values calculation.
- Regional vector of rainfall indexes
method, adapted to the critic of monthly and annual rainfall.
- Computation of average rainfall on a watershed,
using Thiessen or Inverse of Squared Distance
methods (in that last case, a coloured contour map of rainfall
can be obtained).
- Exchange
of station identification system, to switch from
a system to another one.
Finally, a few additional functions are projected:Integration
of a module for multiple correlations and
flood propagation using a correlative method.
- Production
of Arcview Shape files from the
station table.
- Computation
of ETP.
- Connexion
to a monthly hydrological budget model.
|
|
