User:A09/Trebuščica

The Trebuščica (also Trebuša) is a 14-kilometre-long river in western Slovenia and a right tributary of the Idrijca River. The river creates a valley that separates the Vojsko and Čepovan plateaus.

Name
The etymology of 'Trebuščica' is not clear, nor is it clear whether the hydronym was a toponym in the past or vice versa. If 'Trebuša' denotes a river, according to Silvo Torkar, the name should be formalized into 'Trebušica'.

Physical geography
The Trebuščica River was described by the Austrian imperial authorities in a military survey in 1785 as being 10 to 20 foots wide, 2 to 3 feet deep, with a fine rocky bed and a swift current.[2] According to an ichthyological survey in 1998, the Trebuščica averages 11 metres wide, with the widest part being 17.7 metres wide, with average depth being 35 cm.[3] The river bed is covered by larger gravel in 30 percent of its surface, gravel in 63 percent and sand in seven percent. Velocity of the river flow was 0,61 m/s and the discharge was 1,6 m3/s. The basin covers 74 km2. The Trebuščica has a Dinaric rainy-snowy regime, with peaks in April and November and troughs in August, for the latter the monthly flow coefficient is 0.55. The trend of the average maximum annual flows between 1961 and 2010 is falling, with a -57.1 per cent downfall or -9.38 m3/s, and the trend of the maximum annual flows is also negative as well.

The Sulphur River, one of the many tributaries of the Trebuscica River, is also one of the two sulphur springs in Slovenia, located near Dolenje Trebus, and the entire stream is only a few metres long. The spring releases water from a Triassic dolomitic aquifer with poorly soluble hydrogen sulphide, which is deposited as white fibres in the stream. The sulphur spring has been probed since 2011[6][7].

Flora and fauna The river is home to genetically pure populations of brown trout (Salmo marmoratus), grayling (Thymallus thymallus) and large dabs (Coregonus lavaretus)[8] In 1993, the project for the rehabilitation of brown trout in the Soča river basin discovered one of the eight genetically pure populations of this fish in the Trebuščica River.[9] The river is also home to a large population of grayling (Thymallus thymallus), brown trout (Salmo marmoratus), grayling (Thymallus thymallus), and large dabs. According to an ichthyological survey in 1998, sockeye trout account for 40 % of the total biomass of the river, one of the highest proportions in the Adriatic basin. The upper six kilometres of the river are a fishery reserve and breeding water, while the lower reaches are fishing water[3].

Statistical analysis was carried out in the course of probing the Sulphur Spring and bacteria phylogenetically similar to Gammaproteobacteria, others to Epsilonproteobacteria and Deltaproteobacteria, three different groups of archaea and eukaryotes from the Alveolata groups were detected. Genetic analysis showed the uniqueness of some of the organisms found. The source is very diverse in the microenvironment and some of the known organisms were found for the first time in this type of habitat[7].