This picture is of Plitvice Lakes National Park.
Explanation:
Plitvice Lakes National Park (Croatian: Nacionalni park Plitvička jezera, colloquially Plitvice, pronounced [plîtʋitse]) is one of the oldest and largest national parks in Croatia.[2] In 1979, Plitvice Lakes National Park was inscribed on the UNESCO World Heritage list, due to its outstanding and picturesque series of tufa lakes, caves, connected by waterfalls.[3]
The national park was founded in 1949 and is in the mountainous karst area of central Croatia, at the border to Bosnia and Herzegovina. The important north–south road that passes through the national park area connects the Croatian inland with the Adriatic coastal region.
The national park is world-famous for its lakes arranged in cascades. Sixteen lakes can be seen from the surface.[6] These lakes are a result of the confluence of several small rivers and subterranean karst rivers. The lakes are all interconnected and follow the water flow. They are separated by natural dams of travertine, which is deposited by the action of moss, algae, and bacteria. The particularly sensitive travertine barriers are the result of an interplay between water, air and plants. The encrusted plants and bacteria accumulate on top of each other, forming travertine barriers which grow at the rate of about 1 cm (0.4 in) per year.
The 16 lakes are separated into an upper and lower cluster formed by runoff from the mountains, descending from an altitude of 636 to 503 m (2,087 to 1,650 ft) over a distance of some 8 kilometres (5.0 mi), aligned in a south–north direction. The lakes collectively cover an area of about 0.77 square miles, the water exiting from the lowest lake forming the Korana River.
The lakes are renowned for their distinctive colors, ranging from azure to green, grey or blue. The colors change constantly depending on the quantity of minerals or organisms in the water and the angle of sunlight.
The Plitvice Lakes originate in the south of the park area at the confluence of Bijela Rijeka (English White River) and Crna Rijeka (English Black River). These rivers originate south of the municipality of Plitvički Ljeskovac and unite at one of the bridges in this village. From this place onwards to the lakes, the water masses are referred to as Matica (English for water current, can also mean root or origin). At the bay of Liman (also called Limun), a part of Prošćansko jezero, another little river flows into the lakes. This river is fed by permanent springs; the water quantity, however, varies. Temporarily, water from other, usually dead creeks reaches Prošćansko jezero from the west.[
The underground configuration of the Plitvice Lakes consists of various geologic features. Generally, the whole area of Plitvice Lakes National Park can be attributed to the South-East European karst area. The typical feature of this karst area is brittle or porous rock, mostly limestone or dolomite. This configuration creates different geomorphological phenomena being referred to as dolina (sinkhole), polje, uvala, ponor, etc.
In the future, the analysis of underground water courses could be an interesting field of research for speleologists. Up to now, little has been known about these unexplored courses. At first sight, a lack of water in the karst region could be ascertained. However, this is only the case on the surface. The major part of natural phenomena takes place underground, where an abundance of water exists.
Due to the features of limestone, many rivers drain away into the rock. Therefore, extensive underground river systems exist. Upon reaching hard rock, rivers emerge on the surface. This phenomenon of underground karst rivers (Croatian rijeka ponornica) can also be observed at the Plitvice Lakes.
Tufa sediments have been formed from the Pleistocene onwards in sinkholes or depressed areas between the surrounding mountains. Generally seen, the underground of the Plitvice Lakes could be categorized into two zones. The Upper Lakes in the south predominantly consist of dolomite rock. The Lower lakes in the north predominantly consist of limestone rock. Dolomite rock is slightly harder than limestone. Though fragile upon physical influence, dolomite rock has lower water permeability properties. In contrast, limestone rock is more compact and massive, but has a higher water permeability.[9]
From an aerial perspective, significant differences between the terrain of the Upper and the Lower Plitvice Lakes can be observed. At the Upper Lakes several little lakes have formed parallel to each other and a rather shallow water flow can be observed. The Lower Lakes, however, are much larger and virtually drill their path through the rock. Furthermore, there are only a few lakes at the Lower Lakes. They have formed a canyon, which continues as river Korana.
