Assessment of the hydromorphological quality of streams in the Venta River Basin District, Latvia

Hydromorphological quality assessment is an important research topic, especially after the implementation of the EU Water Framework Directive. In this study the hydromorphological quality at 46 sites in 22 streams of the Venta River Basin District (RBD) in Latvia was investigated during the vegetation periods of 2011-2013. The UK River Habitat Survey method was used in the research. No significant differences in Habitat Quality Assessment (HQA) and Habitat Modification Scores (HMS) were found between stream types. We found that the most important factor affecting HQA scores in our research territory was instream vegetation, which coincides with results of other researchers. There was a significant negative correlation between HQA and HMS. Distance from the source had a negative correlation with HQA and a positive correlation with HMS. River type had a positive correlation with special features (beaver dams, fringing reed bank, wetlands, etc.). Key words: hydromorphological assessment, River Habitat Survey, Venta RBD, Latvia.