The Ralja ( sr-Cyrl, Раља) is a

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

in the

Šumadija Šumadija ( sr-Cyrl, Шумадија, ) is a geographical region in the central part of Serbia. The area used to be heavily covered with forests, hence the name (from ''šuma'' 'forest'). The city of Kragujevac is the administrative center of t ...

region of

Serbia , image_flag = Flag of Serbia.svg , national_motto = , image_coat = Coat of arms of Serbia.svg , national_anthem = () , image_map = , map_caption = Location of Serbia (gree ...

. It is a 51 km long left

tributary A tributary, or an ''affluent'', is a stream or river that flows into a larger stream (''main stem'' or ''"parent"''), river, or a lake. A tributary does not flow directly into a sea or ocean. Tributaries, and the main stem river into which they ...

to the

Jezava The Jezava ( sr-Cyrl, Језава) is a river in central Serbia. Geography Formerly a distributary of the Great Morava that flowed into the Danube in Smederevo at the Smederevo Fortress, its upper course was separated from the Great Morava b ...

, a

distributary A distributary, or a distributary channel is a stream channel that branches off and flows a main stream channel. It is the opposite of a ''tributary'', a stream that flows another stream or river. Distributaries are a result of river bifurc ...

of the

Great Morava The Great Morava (, ) is the final section of the Morava ( sr-Cyrl, Морава), a major river system in Serbia. Etymology According to Predrag Komatina from the Institute for Byzantine Studies in Belgrade, the Great Morava is named after ...

river. It also gives its name to the surrounding Šumadija's

subregion A subregion is a part of a larger geographical region or continent. Cardinal directions are commonly used to define subregions. There are many criteria for creating systems of subregions; this article is focusing on the United Nations geoschem ...

of Ralja.

Course

The Ralja originates in the northern part of the

Kosmaj Kosmaj (Serbian Cyrillic: Космај, ) is a mountain south of Belgrade. With an elevation of 626 meters, it is the highest point of the entire Belgrade City area and is nicknamed one of two "Belgrade mountains" (the other being the mountain o ...

mountain, north of the village of Velika Ivanča, in the

Sopot Sopot (; or ) is a seaside resort city in Pomerelia on the southern coast of the Baltic Sea in northern Poland, with a population of approximately 40,000. It is located in Pomeranian Voivodeship, Pomerania Province and has the City with powiat ri ...

municipality of the City of

Belgrade Belgrade is the Capital city, capital and List of cities in Serbia, largest city of Serbia. It is located at the confluence of the Sava and Danube rivers and at the crossroads of the Pannonian Basin, Pannonian Plain and the Balkan Peninsula. T ...

. Almost from the source, the river valley is a route for the Belgrade-

Niš Niš (; sr-Cyrl, Ниш, ; names of European cities in different languages (M–P)#N, names in other languages), less often spelled in English as Nish, is the list of cities in Serbia, third largest city in Serbia and the administrative cente ...

railway. At the villages of Popović and Mali Požarevac, the Ralja turns straight to the east for the rest of its flow and also from this point, the Belgrade-Niš highway joins the railroad. As it flows next to the Belgrade suburbs of Dražanj,

Umčari Umčari (Serbian Cyrillic: Умчари) is a suburban settlement of Belgrade, the capital of Serbia. It is located in Belgrade's municipality of Grocka. Umčari is located in the southeastern part of the municipality, in the northern Šumadija r ...

and Živkovac, the Ralja divides the

Podunavlje Podunavlje is the name of the Danube river basin parts located in Croatia (Slavonia, Syrmia, and Baranya) and Serbia (Vojvodina, Belgrade and Eastern Serbia). Podunavlje is located on the southern edge of Pannonian Basin. In its wider meaning, ...

region from the Ralja region of the low Šumadija, and leaves the City of Belgrade area at the village of Malo Orašje. After the villages of Binovac,

Kolari Kolari is a municipality of Finland at the Swedish border, which follows the Torne River, the longest free-flowing river in Europe. It is located in the region of Lapland. The municipality has a population of () and covers an area of of w ...

, Vrbovac and Ralja, the river separates from the highway turning north at the village of Vranovo and empties into the one of several arms of the

Smederevo Smederevo ( sr-Cyrl, Смедерево, ) is a list of cities in Serbia, city and the administrative center of the Podunavlje District in eastern Serbia. It is situated on the right bank of the Danube, about downstream of the Serbian capital, ...

's suburb of

Radinac Radinac ( sr-cyr, Радинац) is a village in the municipality of Smederevo, Serbia , image_flag = Flag of Serbia.svg , national_motto = , image_coat = Coat of arms of Serbia.svg , national_anthem ...

Characteristics

The Ralja drains an area of 310

km² The square kilometre (square kilometer in American spelling; symbol: km2) is a multiple of the square metre, the SI unit of area or surface area. In the SI unit of area (m2), 1 km2 is equal to 1M(m2). 1 km2 is equal to: * 1,000,000 squar ...

, belongs to the

Black Sea The Black Sea is a marginal sea, marginal Mediterranean sea (oceanography), mediterranean sea lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bound ...

drainage basin A drainage basin is an area of land in which all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, ...

, and is not navigable. In July 2021, city announced that project for flash flood warning system is being applied on several rivers and streams on the territory of Belgrade, including the watershed of Ralja. Hydrological stations and

rain gauge A rain gauge (also known as udometer, ombrometer, pluviometer and hyetometer) is an instrument used by meteorologists and Hydrology, hydrologists to gather and measure the amount of liquid precipitation in a predefined area, over a set period of t ...

s will be placed to monitor the water level. Ralja is known as relatively small stream, which however floods the surroundings during the heavy rains. By March 2023 three hydrologocal stations were placed along the river, at Dražanj, Umčari and Živkovac, while the fourth was placed at the confluence of the Kamendol creek. In the lower section, Ralja is even more polluted, as there it receives the discharge canal of the Smederevo Ironworks wastewaters. Measurements from October 2021 and August 2022 showed high and prohibited levels of cadmium, lead, copper and zinc in river's mud. The water is completely red in this section.

References

Sources

* ''Mala Prosvetina Enciklopedija'', Third edition (1985); Prosveta; * Jovan Đ. Marković (1990): ''Enciklopedijski geografski leksikon Jugoslavije''; Svjetlost-Sarajevo; {{ISBN, 86-01-02651-6 Rivers of Serbia

Course

Characteristics

See also

References

Sources