River restoration has become increasingly attractive worldwide as it provides considerable benefits to the environment as well as to the economy. This study focuses on changes of hydromorphological ...conditions in a small lowland river recorded during an experiment carried out in the Flinta River, central Poland. The proposed solution was a pilot project of the construction of vegetative sediment traps (plant basket hydraulic structures - PBHS). A set of three PBSH was installed in the riverbed in one row and a range of hydraulic parameters were recorded over a period of three years (six measurement sessions). Changes of sediment grain size were analysed, and the amount and size of plant debris in the plant barriers were recorded. Plant debris accumulation influencing flow hydrodynamics was detected as a result of the installation of vegetative sediment traps. Moreover, various hydromorphological processes in the river were initiated. Additional simulations based on the detected processes showed that the proposed plant basket hydraulic structures can improve the hydromorphological status of the river.
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•Plant basket hydraulic structures (PBHS) initiate changes in hydrodynamic conditions.•PBHS modifies sediment accumulation and river bottom type diversification.•The mechanism relies on initiating of morphological forms typical for natural rivers.•The increase values of shear stress were observed after a year from PBHS introduction.
The hydromorphological state and habitat quality of the selected streams in the Negev Desert was taken under consideration in the paper. Field studies were conducted in September 2014 on selected ...500 m sections of streams (Nahal Be’er Sheva, Nahal Hebron) characterized by noticeable anthropopressure as well as on streams (Nahal Sansana, Nahal Yatir, Nahal Hatira) without visible human pressure. The survey of the hydromorphological state of selected streams was carried out using a British method, the River Habitat Survey (RHS). The hydromorphological state and habitat quality of the tested streams, based on the habitat naturalness indicator (HQA), as well as the habitat modification indicator (HMS), places the analysed streams of weak anthropopressure in class III—moderate (Nahal Yatir, Nahal Hatira) and IV—poor (Nahal Sansana). Bad hydromorphological state (class V) is the characteristic of the Nahal Hebron and Nahal Be’er Sheva streams with significant human pressure. However, it is important to verify RHS method and the classification of a hydromorphological state, especially the HQA index, and adapt them to the reference conditions in arid and semi-arid areas.
This article contains an analysis of the hydromorphological state of mountain streams under contemporary human impact conditions. The subjects of the study are the Jaszcze and Jamne streams, located ...in the Polish Flysch Carpathians. The hydromorphological state of each stream reflects its habitat quality and depends on a number of natural and anthropogenic features. The research is conducted on the basis of a British method, the River Habitat Survey, which complies with the EU Water Framework Directive. The Habitat Quality Assessment and Habitat Modification Score indices are used to determine the diversification of natural features and the levels of human transformation of the streams studied. The research showed that the largest transformations in stream hydromorphology and habitat conditions occurred in those valley parts characterized by intensive development of building construction and hydrotechnical infrastructure.
The article presents the results of an assessment of the hydromorphological state of selected Carpathian rivers in sections above and below the reservoirs. An attempt has also been made to assess the ...impact of reservoirs on the hydromorphological conditions and quality of river habitats. The research was based on the River Habitat Survey (RHS) method. The synthetic indices Habitat Quality Assessment (HQA) and Habitat Modification Score (HMS) were calculated on the basis of the gathered data for each section studied; this allowed the hydromorphological qualities of the rivers to be assessed numerically. The reservoirs interrupt river continuum, and they alter different biotic and abiotic elements of natural environment. However, this study has shown that the operation of reservoirs does not always negatively impact the hydromorphological conditions of rivers that reflect their habitat quality. The influence of reservoirs on a river's hydromorphological state above and below a reservoir's location may be neutral, but it also can improve the habitat conditions of a river.
Paper’s main goal is to establish “RHS reference site”, which will be the basis for future classification of river habitat quality in other regions of Serbia. River habitats in Golijska Moravica and ...Jerma basin have been assessed and classified by RHS method, and reference values are determined (which would serve for the next research of river habitats in Serbia). In Golijska Moravica and Jerma basin semi–natural and predominantly unmodified habitats with high diversity are dominant. If we compare HQA index of Moravica and Jerma with HQA indexes in some European countries (Austria, Germany) of same river type (small, shallow mountain rivers)we can conclude that sites in Moravica and Jerma basin have higher habitat diversity. Within river basins there are spatial differences of HQA index value. River sites in Moravica and Jerma basin have lower values of HMS index than sites in European countries. The impact of individual characteristics on total HQA and HMS score is also determined in this paper.Results of this paper are important for conservation of natural habitats, for river basin management plans and to estimate environmental impact of future water management activities in these basins.
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