Complex of travertine waterfalls in Martin Brod - Una National Park

Description

National Park "Una" is spread through the valley of the upper stream of the river Una as well as through the valley of the river Unac, right tributary of Una, all the way to the river Krka in the west. This area represents a unique natural complex in this part of Europe, very valuable for the conservation of the total landscape and biodiversity, especially because of:

• Karst formations and hydrology, which are unique in European terms, together with the basin of Korana and Krka;
• Landforms that created one of the few natural routes to the Adriatic Sea;
• Mosaic of habitats, high diversity of plant and animal species, and the presence of relict and endemic species;
• Position on the border of three climate areas;

The Park covers 19.800 hectares of which most are under the territory of the municipality of Bihac. 13.500 hectares are in the regime of strict and aimed protection, while 6.300 hectares are under development regime. The Law defines boarders, regulates issues of protection, promotion and its usage, management of the National Park, misdemeanor offenses and administrative measures for non-compliance with this law.

Rivers Una, Unac and Krka as three jewels of the natural heritage of the Una National Park, make a combination of valuable natural features, of diverse and preserved natural landscapes of exceptional beauty and rich cultural and historical heritage. In the upstream, from the source to Bihać, the overall fall is nearly 3 meters per kilometer. In this section, Una has features of a real mountain river and its travertine waterfalls, cascades and falls are a true jewel of beauty of which are: a big waterfall in Martin Brod, Štrbački buk, Troslap, Dvoslap and Ripač fall. Down at the waterfalls of Martin Brod and Štrbački buk the water crashes over several small and large falls and waterfalls building a unique travertine formations characteristic of this beauty. The living world in Una, which itself contributes to the creation of travertine formation is particularly interesting. With its structure, mosses - bryophytes are suitable for retention of precipitated calcite, that way making an indispensable link in the creation and growth of travertine formation.

In terms of cultural and historical area, this area abounds with a rich heritage of archaeological sites and historical monuments, and the special position of the area on the transit line to the sea led it under the influences of many cultures in the past, from where the rich archaeological sites date, remains of medieval fortresses and religious buildings of different faiths and cultures. The specificity of the river Una is its excessive length of "travertine" flow, with a range of associated phenomena (caves of tufa, travertine islands, barriers and waterfalls), and with extreme forms of pits and the cliffs of a canyon-type, upstream and downstream of Martin Brod and downstream of  Štrbački buk.

Justification of Outstanding Universal Value

Criterion (vii):  Martin Brod is the first major village in Bosnia and Herzegovina and the Una National Park through which the river runs. It is located at the exit from the two canyons, at the point where the Una tributary flows into the river of Una.

Martin Brod harbours the largest complex of waterfalls in the Una National park, with once numerous watermills and bučnica´s – natural-eco laundry. Milančev buk waterfall is one of the sequent waterfalls and cascades which are spread throughout the entire village of Martin Brod all the way to the Unac’s confluence with the Una. This 800 meters long sequence of waterfalls and cascades with a vertical drop of 54 meters is the largest and longest waterfalls complex in the National park.

In the Martin Brod Basin, 0.5 km downstream from the gorge to the fault escarpment Milančev buk (waterfall), the river flows with the characteristics of down flow; several riverbed extensions (3-5) have been formed with calcareous sinter islets and banks. Downstream from the Milančev buk to the confluence with the River Unac, the River Una cuts in by the upper flow water mechanism; its riverbed is full of banks and cascades.

It is especially important to emphasize the connectivity of the river Una, as the basic natural phenomena intended to protect the local population that resides in this area for centuries, which recognizes the value of the river and the area for their own survival, and its uniqueness, which is valuable for preserving local and regional level.

Criterion (ix): Precipitation of tufa in clear natural waters of Una river is caused by a combination of different physical, chemical and biological processes in which carbonate mineral - calcite, dissolved in waters of karst landscaped, is deposited. The process of tufa creation is rigidly conditioned by diverse biotope features which encompass pH, temperature, calcite saturation, concentration of calcium and magnesium. Tufa emerges from solvable calcium-carbonate of the waters of this karts region, in a process in which, through turbulences of clean and cold water and its evaporation, calcium-bicarbonate releases carbon-dioxide and precipitates calcium-carbonate. 

Development of calcerous sinter 
Conditions necessary for calcareous sinter development :

1. Appropriate temperature of the flowing water
2. Water must contain a certain quantity of calcium bicarbonate
3. Existence of live organisms who can retain carbonate sediments
4. Appropriate water velocity.

Tectonically conditioned fault escarpments are the third relief type on which calcareous sinter accumulates. They are characterized by prominent inclinations, which cause the emergence of waterfalls. Water is being intensively ventilated, which leads to the isolation of big quantities of calcareous sinter. In the Basin of Martin Brod, the Una water pours down the succession (about 54 m long) of fault escarpments, calcareous sinter barriers, small barriers and cascades.

The biggest one is Milancev Buk – 10-12 m high, then somewhat lower Jalak and Donji Buk (Kapel, 2000). The Una has cut in calcareous sinter and some calcareous sinter blocks have been discovered in its riverbed, which points to the accumulation stage in the gorge in the time of larger flows or climate changes in the past (Postglacial period).

Throughout its almost entire flow the Una is the river of cascades. Tufa formations such as cascades, river aits, white-water passages, rapids and (combined with tectonic movements) waterfalls represent the most prominent features of this unique river. Waterfalls of different sizes and forms attract numerous visitors, inspire artists but are also of great interest to scientists from different fields of study.

First Una's terrace in Martin Brod area developed by the end of the Pleistocene and in the Postglacial period, when there was a greater flow of the river and its erosion power caused by climate revolutionary changes (higher temperature and humidity, melting of glaciers), so it cut into the floodplain of the period; because of strong additional lateral erosion, the terrace is today preserved only in fragments, mainly at the altitude of 8-10 m above the recent floodplain.

In terms of  chemical composition, tuff  is calcium carbonate (CaCO₃) which is excreted from the waters in karst rivers and from karst sources.The river basins of  tuff rivers mostly have a geological structure of  limestones and dolomites, which dominate in the Dinaric mountain system in Bosnia and Herzegovina. Basin waters enriched with carbon dioxide (CO₂) chemically corrode the carbonate rocks, creating the solution of calcium bicarbonate: CaCO₃ + H2O + CO₂ → Ca (HCO₃)_2.

The process of  tuff  deposition is accelerated by phytogenic processes in water, especially in algae and mosses  which  take  carbon  dioxide  from  the water. This  helps with the extraction of calcium carbon-ate which is deposited on algae, mosses, leaves and branches. According to morphogenetic analysis in the Una, tuff  waterfalls initially originated on tectonic fractures on the thalweg. The water that falls over it is aerated  and tuff  deposition  and  extraction are  intensited. How  strong  the  tuff  deposits  grow is inuenced by the wide spread of waters in several branches over tuff masses. Typical examples of such tuff barriers is Martin Brod is the largest tuff waterfall in Bosnia and Herzegovina. There, from the height of 54 m, approximately 63 m³/s of water flows.

Statements of authenticity and/or integrity

The upper course, which includes the area of Martin Brod is inhabited by 15 species of fish from 4 rows and 6 families. There are 10 recorded species of amphibians (Amphibia) from rows of Anura (bezrepci) and Caudata (repas), in a wider area of the upper course of the river Una which includes the National Park. With its biology, species that are present in this area are generally associated with wet, marsh and aquatic habitats. Species that can be seen are, Triturus carnifex (a large newt), Salamandra atra (Black Salamander) and Proteus anguinus (olm).

Among the 15 species of fish that are present in the river Una and its tributaries at the area of the National Park, the most important are:

• Stream trout (Salmo trutta) is a relatively rare species throughout Europe.
• Grayling (Thymallus Thymalsus) is susceptible to contamination, due to reduced water quality and suitable habitats and that is also the reason it is becoming rarer.

In this area the following reptile species are present: Algyroides nigropunctatus (brown scaly lizard), Lacerta Horvath (Velebit lizard) and Viper macrops (mountainous Karst Meadow Viper). Reptiles of the National Park are mostly common continental species, among which are present some immediate widespread species like: the eastern meadow lizard (Lacerta agilis bosnica) - endemic to the Balkan Peninsula and the Bosnian common adder (Vipera berus bosniensis) - endemic to the Balkan Peninsula. Three more species are considered endemic to the park: Velebit lizard (Arheolacerta horvathi) - endemic species from eastern Alps, mountainous Karst Meadow Viper (Vipera (Ursini) macrops) - endemic to the Balkan Peninsula and brown scaly lizard (Algyroides nigropunctatus) which is endemic to the Dinaric karst.

Comparison with other similar properties

Una National park is situated in Nortwest Bosnia and Herzegovina along the border between B&H and Croatia only 35 km from Plitvice Lakes National Park. This protected area is one of the oldest national parks in Southern Europe and it is also Croatia’s largest and most popular national park and recognized as a natural UNESCO World Heritage Site in Croatia in 1979. The park was established in 1949 in an effort to preserve the mountainous karst area in Central Croatia. The park is located close to the border of Bosnia and Herzegovina. The protected area encompasses 296.85 square kilometers.

Originating as karst spring, the stream quickly swells an falls at Una´s first terrace in Martin Brod is comparable to Plitvice Lakes NP. The Plitvice Lakes basin is a geomorphologic formation of biological origin, a karst river basin of limestone and dolomite, with approximately 20 lakes, created by the deposition of calcium carbonate precipitated in water through the agency of moss, algae and aquatic bacteria. This phenomena of travertine is mostly formed on the spots where water falls from an elevation, by the incrustation of algae and moss with calcium carbonate.

In the future Una National park will become known as a transnational park located in both Bosnia-Herzegovina and Croatia. Given the park’s location, we envision that a future link between the Una National Park and Plitvice National Park will also create a unique and protected calcareous sinter region that will become a respectable tourist attraction, even for European standards.