|
|
|
Hydrology - Assessment of the
natural State of the flow regime
The flow regime: the driving force
of water dynamics
In addition to water quality and the spatial and structural conditions
of waters, the rate of flow is the third decisive influencing factor
for the ecological state of watercourses. Human uses not only affect
the flow rate, but also the time distribution over the day and the
year. Furthermore, they can lead to changes in the sediment regime
and affect water temperatures.
|
 |
| |
Figure 1: A dam – a measure
taken for hydropower use |
Purpose and content of the Hydrology-Flow
Regime module
The Hydrology - Flow Regime module for the so-called spatial step
R (regional scale), HYDMOD-R for short, within the Modular Stepwise
Procedure is the method for describing the hydrological conditions
of a region by identifying water resources management measures and
assessing their effects on the flow regime. It results in a statement
on the hydrological state of the river system of a watershed, with
the individual river reaches as reference for classification. It assesses
and classifies the natural state of the flow regime using nine assessment
indicators, covering various characteristics from the areas of the
low flow, medium flow and high flow regime.
The anthropogenic measures responsible for changes in the flow regime
largely derive from hydropower utilization and urban water resources
management. In order to inventory the water related measures, HYDMOD-R
provides a typology for such measures along with significance criteria.
The assessment is carried out using the nine assessment indicators
initially at the sites with human measures. Subsequently these classifications
at the individual sites are used to assess and classify the river
reaches.
|
Figure 2: Water abstraction on the
Linth River |
|
The HYDMOD-R package
The use of HYDMOD-R requires a number of hydrological parameters.
In many cases however it can be assumed that the data available
are scarce. For this reason, a series of hydrological fundamentals
and estimation procedures have been elaborated parallel to the method
development. Finally a computer program was also developed aiming
to facilitate the application for the user.
HYDMOD-R can therefore be regarded as a package. It focuses on the
actual assessment method. In addition various estimating procedures
are provided. Finally the package is complemented by the electronic
tool (HYDMOD-FIT) made available for IT-supported application, standardisation
and facilitation for the user. In addition, GIS support-files for
the cartographic representation of the assessment results are provided.
|
Figure 3: Hydropeaking discharge
into a river |
 |
| Figure 4: The “package”
module hydrology – flow regime (HYDMOD-R) |
| |
| |
An English summary of the HYDMOD-R methodology (draft
status 2005) can be found in the following document (as presented for
the Headwater 2005 conference).
HYDMOD-F methodology in English : PDF,
628KB
For feedback to the method and the electronic tools
please write to contact.
|
