This study reports on the sedimentary characteristics of Lake Khuvsgul which is located at the southern end of the Baikal Rift System within the continental interior of East Eurasia. With an elevation of 1645 m a.s.l., it has a climate that is mainly controlled by the Siberian-Mongolian high pressure system and the westerly wind systems from the Atlantic Ocean. Lake Khuvsgul, Mongolia’s second largest lake by surface area (2760 km2), is the country’s deepest fresh water lake with a bottom that is only 262 m a.s.l. Fed by 96 rivers and streams, it is drained by the Eg River which, after joining the Selenge River, fl ows into Lake Baikal. Analysis of a 12.3 m core from Borsog Bay near the eastern shore of the lake indicates a sedimentation rate of about 0.08 cm/a. It is believed that this relatively high sedimentation rate is due to the large sedimentary input from River Borsog and the variability of the turbidity currents at depths shallower than 9 m. It further suggests that the large sedimentation rate may be correlated with the annual and seasonal variations in the dominant westerly wind system over the Siberian Plateau. Such variations have resulted in a lowering of lake level and impacted the rate of erosion within the river’s catchment area and therefore the sediment input to the lake. Because this is a preliminary report, further research into the sedimentary dynamics within Lake Khuvsgul and the role played in those dynamics by the climatic variability over Mongolia and Central Asia is planned.
The Water Framework Directive (WFD) introduced the obligation to monitor hydromorphological elements of rivers, including hydrological regime, river continuity, and riverbed morphology. It is estimated that by the year 2015 all uniform water bodies in the EU will be ensured at least very good (class I) or good (class II) ecological status plus good ecological potential. European standards define requirements concerning slightly different quality indices as well as methods of their assessment in such studies. In Poland, hydrological valuation has been realized since the early 1990s using different research methods. Within the framework of appraisals applied at that time, the requirements of the WFD, adopted later, were not always considered. This paper presents results of an analysis conducted on the basis of the findings of all studies of the hydromorphological status of Polish rivers conducted and published in 1995-2008. From 2,202 km of watercourses, in which scoring was applied for selected quality elements, a total of 1,588 km, uniform in terms of methodology, were selected from 35 rivers. Statistical analysis determined the distribution of results for analyzed quality elements, constituting the foundation for a new method of hydromorphological monitoring of rivers, adapted to the requirements of the WFD. Moreover, our paper also presents a review of developed research methods for the hydrological valuation of watercourses, applied in Poland and Europe.
The aim of the study was to demonstrate the relationship between macroinvertebrate assemblages and aquatic vegetation interacting with chemical and geomorphological factors. The survey was carried out in the catchment of a lowland river in Poland in the year 2009. Macroinvertebrate samples were collected on 19 river sites during two campaigns (spring and autumn) and 13 macroinvertebrate metrics were calculated. Indices were selected to reflect pressures associated with organic pollutants, morphological and general degradation of rivers. Hydromorphological assessment was undertaken according to the River Habitat Survey (RHS). Water samples for chemical analysis were collected monthly during the whole year, and nine chemical parameters were analysed. Macrophyte surveys made it possible to calculate seven parameters. It was found that macroinvertebrates collected in spring and autumn showed very different patterns and that only the spring samples showed a significant relationship between macroinvertbrates and water quality, which means that spring sampling is most important for biomonitoring. Only three macroinvertebrate metrics, i.e. SIGI (German Saprobic Index), EPT (indicating the relative abundance of Ephemeroptera, Plecoptera and Trichoptera) and MBI (index used for river ecological status assessment), responded significantly to water pollution. Macrophytes and macroinvertebrates responded differently to environmental gradients and these organism groups deliver different information for monitoring.
W pracy przedstawiono nową metodykę monitoringu hydromorfologicznego cieków sztucznych (MHR). W Polsce ich długość wynosi około 2000 km, co wskazuje na celowość zastosowania dla nich oceny uproszczonej. Ocenę potencjału ekologicznego jednolitej części wód oparto na 4 elementach, 19 wskaźnikach i 34 atrybutach, tworząc w ten sposób hierarchiczny system oceny.
Klasyfikacja ekologiczna rzek według Ramowej Dyrektywy Wodnej uwzględnia ocenę stanu hydromorfologicznego jako elementu uzupełniającego parametry biologiczne. Brytyjska metoda River Habitat Survey (RHS) jest obecnie szeroko stosowaną metodą oceny warunków hydromorfologicznych rzek, wykorzystywaną w wielu krajach Europy. Jej walorem jest m.in. obiektywność i jednoznaczność opisu ekosystemu rzecznego, kompleksowość ujęcia problematyki dolin rzecznych oraz możliwość przedstawiania stanu środowiska w formie indeksów liczbowych. System RHS pozwala na klasyfikowanie wszystkich typów wód płynących w Polsce pod względem ich stanu hydromorfologicznego, zgodnie z wymaganiami stawianymi obecnie w monitoringu. Wyniki badań przeprowadzonych w Polsce w latach 1997–2008 potwierdzają, że RHS może być z powodzeniem zastosowany w naszym kraju.
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