The hydromorphology (old Greek ὕδωρ, hydōr = water; μορφή, morphé = shape / form and λόγος, lógos = word, doctrine, reason) describes the actually existing water structures and the associated runoff behavior of a water body in its spatial and temporal extent. Due to the human overprint of many bodies of water, this includes both naturally created forms (e.g. gravel banks, differences in currents and substrates, bays and spurs) as well as anthropogenic structures and their effects (backwater through weir systems, bank construction, river straightening, etc.).
In most federal states, the description and assessment of the hydromorphological status of a flowing water is carried out by recording the water structure quality .
The structural condition of many brooks and rivers has deteriorated drastically due to the sometimes centuries-old expansion of the water. In order to improve the state of water again, the EU passed the European Water Framework Directive in 2000 , which was implemented in Germany in the Water Management Act and in the state water laws. The main objective of this guideline is to achieve an improvement in the hydrobiology (fish, small organisms, aquatic plants), which inevitably only involves reducing the chemical-physical load (hydrochemistry: e.g. material inputs, heat) and / or improving the Water structure (hydromorphology) is achievable. In Annex V, point 1.1.1 of the guideline , the following aspects are named for rivers under the so-called hydromorphological quality components, which are to be considered as a measure of the hydromorphology:
- Water balance (runoff and runoff dynamics, connection to groundwater bodies)
- Patency of the river
- Morphological conditions (depth and width variation, structure and substrate of the river bed, structure of the bank zone)
However, these aspects are only considered as supportive in the course of the implementation of the guidelines (auxiliary variables). The statement of the hydrobiology (biological quality components according to the guideline) is always decisive for a produced improvement.
An improvement in the hydromorphology is usually referred to colloquially as renaturation . In order to better assess the effect of hydromorphological improvements on biology, the interdisciplinary ethohydraulics was developed at the Institute for Water and Water Development at the University of Karlsruhe in collaboration with biologists from the Institute for Applied Ecology from 2007 to 2009 .
- Water Framework Directive in German: http://www.wrrl-info.de/docs/00wrr_de.pdf
- Wassernetz Wiki NRW: http://www.wassernetz-nrw.de/wiki/index.php?title=Hauptseite