Brackish water, also sometimes termed brack water, is water occurring in a natural environment having more salinity than freshwater, but not as much as seawater. It may result from mixing seawater with fresh water together, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root brak. Certain human activities can produce brackish water, in particular civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater shrimp farming. Brackish water is also the primary waste product of the salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it is damaging to the environment.
Geographically, Iran is located in West Asia and borders the Caspian Sea, Persian Gulf, and Gulf of Oman. Its mountains have helped to shape both the political and the economic history of the country for several centuries. The mountains enclose several broad basins, on which major agricultural and urban settlements are located. Until the 20th century, when major highways and railroads were constructed through the mountains to connect the population centers, these basins tended to be relatively isolated from one another.
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environments and are an example of an ecotone. Estuaries are subject both to marine influences such as tides, waves, and the influx of saline water and to fluvial influences such as flows of freshwater and sediment. The mixing of seawater and freshwater provides high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world.
Gorgan, formerly Esterabad , is the capital city of Golestan Province, Iran. It lies approximately 400 km (250 mi) to the north east of Tehran, some 30 km (19 mi) away from the Caspian Sea. In the 2006 census; its population was 269,226, in 73,702 families.
Mazandaran Province and, is an Iranian province located along the southern coast of the Caspian Sea and in the adjacent Central Alborz mountain range, in central-northern Iran.
The Red River, also known as the Hong River, the Hồng Hà and Sông Cái (lit. "Mother River") in Vietnamese, and the Yuan River in Chinese, is a 1,149-kilometer (714 mi)-long river that flows from Yunnan in Southwest China through northern Vietnam to the Gulf of Tonkin. According to C. Michael Hogan, the associated Red River Fault was instrumental in forming the entire South China Sea at least as early as 37 million years before present.
The Kura is an east-flowing river south of the Greater Caucasus Mountains which drains the southern slopes of the Greater Caucasus east into the Caspian Sea. It also drains the north side of the Lesser Caucasus while its main tributary, the Aras, drains the south side of those mountains. Starting in northeastern Turkey, it flows through Turkey to Georgia, then to Azerbaijan, where it receives the Aras as a right tributary, and enters the Caspian Sea at Neftçala. The total length of the river is 1,515 kilometres (941 mi).
Golestān Province is one of the 31 provinces of Iran, located in the north-east of the country and south-east of the Caspian Sea. Its capital is Gorgan.
In geomorphology, an outburst flood—a type of megaflood—is a high-magnitude, low-frequency catastrophic flood involving the sudden release of a large quantity of water. During the last deglaciation, numerous glacial lake outburst floods were caused by the collapse of either ice sheets or glaciers that formed the dams of proglacial lakes. Examples of older outburst floods are known from the geological past of the Earth and inferred from geomorphological evidence on Mars. Landslides, lahars, and volcanic dams can also block rivers and create lakes, which trigger such floods when the rock or earthen barrier collapses or is eroded. Lakes also form behind glacial moraines, which can collapse and create outburst floods.
The Great Wall of Gorgan is a Sasanian-era defense system located near modern Gorgan in the Golestān Province of northeastern Iran, at the southeastern corner of the Caspian Sea. The western, Caspian Sea, end of the wall is near the remains of the fort at: 37.13981°N 54.1788733°E; the eastern end of the wall, near the town of Pishkamar, is near the remains of the fort at: 37.5206739°N 55.5770498°E. The title coordinate is for the location of the remains of a fort midway along the wall.
Lake Hāmūn, or the Hamoun Oasis, is a seasonal lake and wetlands in the endorheic Sīstān Basin in the Sistan region on the Afghanistan–Iran border. In Iran, it is also known as Hāmūn-e Helmand, Hāmūn-e Hīrmand, or Daryācheh-ye Sīstān.
Gonbad-e Kavus is the Iranian city known historically as Gorgan/Hyrcania. The modern name, meaning "the tower of Kavus", is a reference to the most imposing ancient monument in the city. The historic name cannot now be restored, because it was assigned to the neighboring historical city of Astarabad in the 1930s by the Iranian government. At one point, it was even known as the city of Dashte Gorgan, meaning "the Plains of Gorgan".
The Ochlockonee River is a fast running river, except where it has been dammed to form Lake Talquin in Florida, originating in Georgia and flowing for 206 miles (332 km) before terminating in Florida.
Northern Iran consists of the Southern border of the Caspian Sea and the Alborz- mountains.
The Sefid-Rud is a river approximately 670 kilometres (416 mi) long, rising in the Alborz mountain range of northwestern Iran and flowing generally northeast to enter the Caspian Sea at Rasht. The river is Iran's second longest river after the Karun.
The Caspian Hyrcanian mixed forests ecoregion, in the world's temperate broadleaf and mixed forests biome, are a zone of lush lowland and montane forests covering about 55,000 square kilometres (21,000 sq mi) adjoining the shores of the Caspian Sea of Iran and part of that of Azerbaijan. The forest is named after the ancient region of Hyrcania.
The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central Asia, south of the fertile plains of Southern Russia in Eastern Europe, and north of the mountainous Iranian Plateau of Western Asia. It covers 143,550 sq mi (372,000 km2) and a volume of 78,200 km3 (19,000 cu mi). It has a salinity of approximately 1.2%, about a third that of average seawater. It is bounded by Kazakhstan from mid-north to mid-east, Russia from mid-north to mid-west, Azerbaijan to the southwest, Iran to the south and adjacent corners, and Turkmenistan along southern parts of its eastern coast.
Jiroft Dam is a hydroelectric dam in Iran with an installed electricity generating capability of 85 MWh situated in Kerman Province. The fifth concrete dam built in the country, it was begun in 1975 and completed in 1992. It is located on Halil River (Halilrood) 40 km upstream of Jiroft in the narrow valley of Narab. Its reservoir capacity is around 410 million cubic metres up to the normal level. The maximum height of the dam is 134 m and the crest length is 277 m. The dam in its first water year of operation (1992) survived an extraordinary flood with the peak discharge of 5035 cubic metres per second. The flood had a return period of 800 to 1000 years. The heavy rains of this year caused the dam was filled of water much sooner than the planned water storing duration. The spillways and other hydrodynamic outlets of the dam can manage to discharge up to 6500 cubic meters per seconds . The reservoir is planned to irrigate 14200 hectares of the downstream lands.
Qarasu is a river in Golestan Province of Iran which flows to the Caspian Sea.
From mid-March to April 2019 widespread flash flooding affected large parts of Iran, most severely in Golestan, Fars, Khuzestan, Lorestan, and other provinces. Iran has been hit by three major waves of rain and flooding over the course of two weeks which led to flooding in at least 26 of Iran's 31 provinces and at least 70 people died nationwide as of 6 April, according to the officials. The first wave of rain began on 17 March, leading to flooding in two northern provinces, Golestan and Mazandaran with the former province receiving as much as 70 percent of its average annual rainfall in single day. Several large dams have been overflowed, particularly in Khuzestan and Golestan, therefore many villages and several cities have been evacuated. About 1,900 cities and villages across country have been damaged by severe floods as well as hundreds of millions of dollars of damage to water and agriculture infrastructure. 78 roads were blocked and the reliability of 84 bridges was questioned.
