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99-658: It flows into the Persian Gulf of the Indian Ocean 25 km southwest of Hendijan , in the southeast of Khuzestan , where it forms the Hendijan Delta. Tributaries of the Zohreh are Fahlian, and Kheyrabad. The catchment area of the Zohreh is about 17,150 km (6,620 sq mi) of these 14,100 km (5,400 sq mi) is mountainous. The rest of the catchment consists of plains and mountainous foothills. In antiquity it

198-432: A density current that deposits its sediments as turbidites . When the river water is less dense than the basin water, as is typical of river deltas on an ocean coastline, the delta is characterized by hypopycnal flow in which the river water is slow to mix with the denser basin water and spreads out as a surface fan. This allows fine sediments to be carried a considerable distance before settling out of suspension. Beds in

297-679: A Portuguese force led by commander Antonio Correia invaded Bahrain to take control of the wealth created by its pearl industry. On April 29, 1602, Shāh Abbās , the Persian emperor of the Safavid Persian Empire , expelled the Portuguese from Bahrain, and that date is commemorated as National Persian Gulf day in Iran . With the support of the British fleet, in 1622 'Abbās took the island of Hormuz from

396-563: A combination of fresh and salt water for growth, and act as nurseries for many crabs, small fish, and insects; these fish and insects are the source of food for many of the marine birds that feed on them. Mangroves are a diverse group of shrubs and trees belonging to the genus Avicennia or Rhizophora that flourish in the salt water shallows of the Persian Gulf, and are the most important habitats for small crustaceans that dwell in them. They are as crucial an indicator of biological health on

495-485: A common location for civilizations to flourish due to access to flat land for farming, freshwater for sanitation and irrigation , and sea access for trade. Deltas often host extensive industrial and commercial activities, and agricultural land is frequently in conflict. Some of the world's largest regional economies are located on deltas such as the Pearl River Delta , Yangtze River Delta , European Low Countries and

594-537: A delta but enter into the sea in the form of an estuary . Notable examples include the Gulf of Saint Lawrence and the Tagus estuary. In rare cases, the river delta is located inside a large valley and is called an inverted river delta . Sometimes a river divides into multiple branches in an inland area, only to rejoin and continue to the sea. Such an area is called an inland delta , and often occurs on former lake beds. The term

693-533: A fan. The more often the flow changes course, the shape develops closer to an ideal fan because more rapid changes in channel position result in a more uniform deposition of sediment on the delta front. The Mississippi and Ural River deltas, with their bird's feet, are examples of rivers that do not avulse often enough to form a symmetrical fan shape. Alluvial fan deltas, as seen by their name, avulse frequently and more closely approximate an ideal fan shape. Most large river deltas discharge to intra-cratonic basins on

792-633: A few coral reefs . Compared to the Red Sea, the coral reefs in the Persian Gulf are relatively few and far between. This is primarily connected to the influx of major rivers, especially the Shatt al-Arab (Euphrates and Tigris), which carry large amounts of sediment (most reef-building corals require strong light) and causes relatively large variations in temperature and salinity (corals in general are poorly suited to large variations). Nevertheless, coral reefs have been found along sections of coast of all countries in

891-399: A few main distributaries. Once a wave-dominated or river-dominated distributary silts up, it is abandoned, and a new channel forms elsewhere. In a tidal delta, new distributaries are formed during times when there is a lot of water around – such as floods or storm surges . These distributaries slowly silt up at a more or less constant rate until they fizzle out. A tidal freshwater delta is

990-535: A flat arid area splits into channels that evaporate as it progresses into the desert. The Okavango Delta in Botswana is one example. See endorheic basin . The generic term mega delta can be used to describe very large Asian river deltas, such as the Yangtze , Pearl , Red , Mekong , Irrawaddy , Ganges-Brahmaputra , and Indus . The formation of a delta is complicated, multiple, and cross-cutting over time, but in

1089-593: A giant field across the territorial median line (North Field in the Qatari sector; South Pars Field in the Iranian sector). Using this gas, Qatar has built up a substantial liquefied natural gas (LNG) and petrochemical industry. In 2002, the Persian Gulf nations of Bahrain, Iran, Iraq, Kuwait, Qatar, Saudi Arabia, and the UAE produced about 25% of the world's oil, held nearly two-thirds of the world's crude oil reserves , and about 35% of

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1188-573: A hypocynal delta dip at a very shallow angle, around 1 degree. Fluvial-dominated deltas are further distinguished by the relative importance of the inertia of rapidly flowing water, the importance of turbulent bed friction beyond the river mouth, and buoyancy . Outflow dominated by inertia tends to form Gilbert-type deltas. Outflow dominated by turbulent friction is prone to channel bifurcation, while buoyancy-dominated outflow produces long distributaries with narrow subaqueous natural levees and few channel bifurcations. The modern Mississippi River delta

1287-439: A mature delta with a distributary network. Another way these distributary networks form is from the deposition of mouth bars (mid-channel sand and/or gravel bars at the mouth of a river). When this mid-channel bar is deposited at the mouth of a river, the flow is routed around it. This results in additional deposition on the upstream end of the mouth bar, which splits the river into two distributary channels. A good example of

1386-423: A sedimentary deposit formed at the boundary between an upland stream and an estuary, in the region known as the "subestuary". Drowned coastal river valleys that were inundated by rising sea levels during the late Pleistocene and subsequent Holocene tend to have dendritic estuaries with many feeder tributaries. Each tributary mimics this salinity gradient from its brackish junction with the mainstem estuary up to

1485-447: A simple delta three main types of bedding may be distinguished: the bottomset beds, foreset/frontset beds, and topset beds. This three-part structure may be seen on small scale by crossbedding . Human activities in both deltas and the river basins upstream of deltas can radically alter delta environments. Upstream land use change such as anti-erosion agricultural practices and hydrological engineering such as dam construction in

1584-465: Is a diverse cradle for many species who depend on each other for survival. However, the Persian Gulf is not as biologically diverse as the Red Sea . Overall, the wildlife of the Persian Gulf is endangered from both global factors, and regional, local negligence. Most pollution is from ships; land generated pollution counts as the second most common source of pollution. Along the mediterranean regions of

1683-542: Is a good example of a fluvial-dominated delta whose outflow is buoyancy-dominated. Channel abandonment has been frequent, with seven distinct channels active over the last 5000 years. Other fluvial-dominated deltas include the Mackenzie delta and the Alta delta. A Gilbert delta (named after Grove Karl Gilbert ) is a type of fluvial-dominated delta formed from coarse sediments, as opposed to gently sloping muddy deltas such as that of

1782-424: Is a triangular landform created by the deposition of the sediments that are carried by the waters of a river , where the river merges with a body of slow-moving water or with a body of stagnant water. The creation of a river delta occurs at the river mouth , where the river merges into an ocean , a sea , or an estuary , into a lake , a reservoir , or (more rarely) into another river that cannot carry away

1881-565: Is also a closely associated area. 30°04′00″N 49°30′27″E  /  30.0668°N 49.5076°E  / 30.0668; 49.5076 Persian Gulf The Persian Gulf , sometimes called the Arabian Gulf , is a mediterranean sea in West Asia . The body of water is an extension of the Indian Ocean located between Iran and the Arabian Peninsula . It is connected to

1980-576: Is called by the Ionians ", including describing the outflow of silt into the sea and the convexly curved seaward side of the triangle. Despite making comparisons to other river systems deltas, Herodotus did not describe them as "deltas". The Greek historian Polybius likened the land between the Rhône and Isère rivers to the Nile Delta, referring to both as islands, but did not apply the word delta. According to

2079-470: Is destroyed, or occupied by man-made structures. This has had a negative impact on the crustaceans that rely on the mangrove, and in turn on the species that feed on them. The Persian Gulf and its coastal areas are the world's largest single source of petroleum, and related industries dominate the region. Safaniya Oil Field , the world's largest offshore oilfield , is located in the Persian Gulf. Large gas finds have also been made, with Qatar and Iran sharing

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2178-494: Is home to many islands such as Bahrain, an Arab state. Geographically, the biggest island in the Persian Gulf is Qeshm island , belonging to Iran and located in the Strait of Hormuz . Other significant islands in the Persian Gulf include Greater Tunb , Lesser Tunb and Kish administered by Iran, Bubiyan administered by Kuwait, Tarout administered by Saudi Arabia, and Dalma administered by UAE. In recent years, there has also been

2277-430: Is negatively affected by new developments along the Persian Gulf coastline, particularly the construction of artificial islands by Arab states and pollution from oil spills caused during the "Persian Gulf war" and various other natural and artificial causes. Uncontrolled hunting has also had a negative impact on the survival of dugongs. After Australian waters, which are estimated to contain some 80,000 dugong inhabitants,

2376-408: Is now the Iranian province of Bushehr , is an example of such commercial port. Siraf, was also significant in that it had a flourishing commercial trade with China by the fourth century, having first established connection with the far east in 185 AD. Portuguese influence in the Persian Gulf lasted for 250 years; however, since the beginning of the 16th century, Portuguese dominance contended with

2475-538: Is so named because the shape of the Nile Delta approximates the triangular uppercase Greek letter delta . The triangular shape of the Nile Delta was known to audiences of classical Athenian drama ; the tragedy Prometheus Bound by Aeschylus refers to it as the "triangular Nilotic land", though not as a "delta". Herodotus 's description of Egypt in his Histories mentions the Delta fourteen times, as "the Delta, as it

2574-610: Is still a deficit of 416 cubic kilometres (100 cu mi) per year. This difference is supplied by currents at the Strait of Hormuz . The water from the Persian Gulf has a higher salinity, and therefore exits from the bottom of the Strait, while ocean water with less salinity flows in through the top. Another study revealed the following numbers for water exchanges for the Persian Gulf: evaporation = –1.84 m (6.0 ft)/year, precipitation = 0.08 m (0.26 ft)/year, inflow from

2673-502: Is used by the International Hydrographic Organization . The dispute in naming has become especially prevalent since the 1960s. Rivalry between Iran and some Arab states, along with the emergence of pan-Arabism and Arab nationalism , has seen the name "Arabian Gulf" become predominant in most Arab countries. Names beyond these two have also been applied to or proposed for this body of water. The region of

2772-718: The Al Qasimi tribe. This led to the British mounting the Persian Gulf campaign of 1819 . The campaign led to the signing of the General Maritime Treaty of 1820 between the British and the Sheikhs of what was then known as the ' Pirate Coast '. From 1763 until 1971, the British Empire maintained varying degrees of political control over some of the Persian Gulf states, including the United Arab Emirates (originally called

2871-641: The Greater Tokyo Area . The Ganges–Brahmaputra Delta , which spans most of Bangladesh and West Bengal and empties into the Bay of Bengal , is the world's largest delta. The Selenga River delta in the Russian republic of Buryatia is the largest delta emptying into a body of fresh water, in its case Lake Baikal . Researchers have found a number of examples of deltas that formed in Martian lakes . Finding deltas

2970-483: The Gulf of Oman in the east by the Strait of Hormuz . The Shatt al-Arab river delta forms the northwest shoreline. The Persian Gulf has many fishing grounds, extensive reefs (mostly rocky, but also coral ), and abundant pearl oysters , however its ecology has been damaged by industrialization and oil spills . The Persian Gulf is in the Persian Gulf Basin , which is of Cenozoic origin and related to

3069-551: The Nile in the west, as well as Sind waterway, in India. The Achaemenid high naval command had established major naval bases located along Shatt al-Arab river, Bahrain, Oman, and Yemen. The Persian fleet would soon not only be used for peacekeeping purposes along the Shatt al-Arab but would also open the door to trade with India via Persian Gulf. Following the fall of Achaemenid Empire, and after

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3168-526: The Nile Delta and Colorado River Delta are some of the most extreme examples of the devastation caused to deltas by damming and diversion of water. Historical data documents show that during the Roman Empire and Little Ice Age (times when there was considerable anthropogenic pressure), there was significant sediment accumulation in deltas. The industrial revolution has only amplified the impact of humans on delta growth and retreat. Ancient deltas benefit

3267-526: The Trucial States ) and at various times Bahrain, Kuwait, Oman, and Qatar through the British Residency of the Persian Gulf . The Persian Gulf was a battlefield of the 1980–1988 Iran–Iraq War , in which each side attacked the other's oil tankers . It is the namesake of the 1991 Gulf War , the largely air- and land-based conflict that followed Iraq 's invasion of Kuwait . The United States' role in

3366-587: The United Arab Emirates ; Saudi Arabia; Qatar , on a peninsula off the Saudi coast; Bahrain , an island nation; Kuwait ; and Iraq in the northwest. Various small islands also lie within the Persian Gulf, some of which are the subject of territorial disputes between the states in the region. Exclusive economic zones in the Persian Gulf: Countries by coastline length : The Persian Gulf

3465-446: The collared kingfishers were raised by conservationists over real estate development by the United Arab Emirates and Oman. Estimates from 2006 showed that only three viable nesting sites were available for this ancient bird, one located 80 miles (129 km) from Dubai, and two smaller sites in Oman. Such real estate expansion could prove devastating to this subspecies. A UN plan to protect

3564-604: The subduction of the Arabian Plate under the Zagros Mountains . The current flooding of the basin started 15,000 years ago due to rising sea levels of the Holocene glacial retreat . The International Hydrographic Organization defines the Persian Gulf's southern limit as "The Northwestern limit of Gulf of Oman". This limit is defined as "A line joining Ràs Limah (25°57'N) on the coast of Arabia and Ràs al Kuh (25°48'N) on

3663-610: The " Persian Corridor ". Britain utilized the Persian Gulf as the entry point for the supply chain in order to make use of the Trans-Iranian Railway . The Persian Gulf therefore became a critical maritime path through which the Allies transported equipment to Soviet Union against the Nazi invasion . The piracy in the Persian Gulf was prevalent until the 19th century. Many of the most notable historical instances of piracy were perpetrated by

3762-515: The Arabian Sea, including the Persian Gulf, the Red Sea , the Gulf of Kutch , the Gulf of Suez , the Gulf of Aqaba , the Gulf of Aden , and the Gulf of Oman , dolphins and finless porpoises are the most common marine mammals in the waters, while larger whales and orcas are rarer today. Historically, whales had been abundant in the Persian Gulf before commercial hunts wiped them out. Whales were reduced even further by illegal mass hunts by

3861-678: The Greek geographer Strabo , the Cynic philosopher Onesicritus of Astypalaea , who accompanied Alexander the Great 's conquests in India , reported that Patalene (the delta of the Indus River ) was "a delta" ( Koinē Greek : καλεῖ δὲ τὴν νῆσον δέλτα , romanized:  kalei de tēn nēson délta , lit.   'he calls the island a delta'). The Roman author Arrian 's Indica states that "the delta of

3960-463: The Gulf of Aqaba), omura's whale , minke whale , and orca also swim into the Persian Gulf, while many other large species such as blue whale , sei , and sperm whales were once migrants into the Gulf of Oman and off the coasts in deeper waters, and still migrate into the Red Sea, but mainly in deeper waters of outer seas. In 2017, waters of the Persian Gulf along Abu Dhabi were revealed to hold

4059-683: The Lakhum tribe , who lived in what is now Yemen, migrated north and founded the Lakhmid Kingdom along the southern coast. Occasional ancient battles took place along the Persian Gulf coastlines, between the Sassanid Persian empire and the Lakhmid Kingdom, the most prominent of which was the invasion led by Shapur II against the Lakhmids, leading to Lakhmids' defeat, and advancement into Arabia, along

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4158-608: The Middle East adjacent to the Gulf. The world's oldest known civilization ( Sumer ) developed along the Persian Gulf and southern Mesopotamia . The oldest evidence in the world for seagoing vessels has been found at H3 in Kuwait, dating to the mid-sixth millennium BC, when the Gulf was part of an extensive trade network that involved the Ubaid settlements in Mesopotamia and communities along

4257-452: The Middle East are located in this region. The wildlife of the Persian Gulf is diverse, and entirely unique because of the Persian Gulf's geographic distribution and its isolation from the international waters only breached by the narrow Strait of Hormuz . The Persian Gulf has hosted some of the most magnificent marine fauna and flora, some of which are near extirpation or at serious environmental risk. From corals, to dugongs , Persian Gulf

4356-497: The Mississippi. For example, a mountain river depositing sediment into a freshwater lake would form this kind of delta. It is commonly a result of homopycnal flow. Such deltas are characterized by a tripartite structure of topset, foreset, and bottomset beds. River water entering the lake rapidly deposits its coarser sediments on the submerged face of the delta, forming steeping dipping foreset beds. The finer sediments are deposited on

4455-442: The Persian Gulf by the United Arab Emirates and Oman also raised concerns that habitats of species such as the hawksbill turtle , greater flamingo , and booted warbler may be destroyed. The dolphins that frequent the Persian Gulf in northern waters around Iran are also at risk. Recent statistics and observations show that dolphins are at danger of entrapment in purse seine fishing nets and exposure to chemical pollutants; perhaps

4554-490: The Persian Gulf grew in the second half of the 20th century. On July 3, 1988, Iran Air Flight 655 was shot down by the U.S. military (which had mistaken the Airbus A300 operating the flight for an Iranian F-14 Tomcat ) while it was flying over the Persian Gulf, killing all 290 people on board. The United Kingdom maintains a profile in the region; in 2006 alone, over 1 million British nationals visited Dubai . In 2018,

4653-602: The Persian Gulf has been inhabited since the Paleolithic . During most of the Last Glacial Period (115,000–11,700 years Before Present ), due to lowered sea levels (reaching around 125 metres (410 ft) metres below present values during the Last Glacial Maximum ) combined with the shallow depth of the Gulf (on average around 35 metres (115 ft) and at max around 100 metres (330 ft) metres depth) most of

4752-422: The Persian Gulf in recent years. Aside from direct damage to the coral, the construction waste creates "traps" for marine life in which they are trapped and die. The result has been a dwindling population of the coral, and as a result a decrease in number of species that rely on the corals for their survival. A great example of this symbiosis are the mangroves in the Persian Gulf, which require tidal flow and

4851-517: The Persian Gulf was called Pūdīg , which comes from Avestan : Pūitika , lit.   'cleansing', a name mentioned in Bundahishn . The body of water is historically and internationally known as the Persian Gulf. Arab governments refer to it as the Arabian Gulf or The Gulf, and other countries and organizations have begun using Arabian Gulf. The name Gulf of Iran (Persian Gulf)

4950-566: The Persian Gulf was called many different names. The Assyrians called it the "Bitter Sea". In 550 BC, the Achaemenid Empire established the first ancient empire in Persis ( Pars , or modern Fars , also known as Persia), in the southwestern region of the Iranian plateau . Consequently, in the Greek sources, the body of water that bordered this province came to be known as the "Persian Gulf". In

5049-455: The Persian Gulf was exposed as dry land, forming a flat floodplain where a number of rivers converged. This region may have served as an environmental refuge for early humans during periodic hyperarid climate oscillations. The modern marine Gulf was formed when sea level rose during the early Holocene , from around 12,000 to 6,000 years ago. The flooding of the Gulf may have stimulated the development of Neolithic farming cultures in regions of

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5148-448: The Persian Gulf. Corals are vital ecosystems that support multitude of marine species, and whose health directly reflects the health of the Persian Gulf. Recent years have seen a drastic decline in the coral population in the Persian Gulf, partially owing to global warming but mostly to irresponsible dumping by Arab states like the UAE and Bahrain. Construction garbage such as tires, cement, and chemical by products have found their way to

5247-563: The Persian Gulf. Persian naval forces laid the foundation for a strong Persian maritime presence in Persian Gulf, that started with Darius I and existed until the arrival of the British East India Company , and the Royal Navy by mid-19th century AD. Persians were not only stationed on islands of the Persian Gulf, but also had ships often of 100 to 200 capacity patrolling empire's various rivers including Shatt-al-Arab , Tigris , and

5346-441: The Portuguese; much of the trade was diverted to the town of Bandar 'Abbās , which he had taken from the Portuguese in 1615 and had named after himself. The Persian Gulf was therefore opened to a flourishing commerce with the Portuguese, Dutch, French, Spanish and the British merchants, who were granted particular privileges. The Ottoman Empire reasserted itself into Eastern Arabia in 1871. Under military and political pressure from

5445-467: The Soviet Union and Japan in the 1960s and 1970s. Along with Bryde's whales , these once common residents can still can be seen in deeper marginal seas such as Gulf of Aden, Israel coasts, and in the Strait of Hormuz . Other species such as the critically endangered Arabian humpback whale , (also historically common in Gulf of Aden and increasingly sighted in the Red Sea since 2006, including in

5544-426: The Strait = 33.66 m (110.4 ft)/year, outflow from the Strait = -32.11 m (105.3 ft)/year, and the balance is 0 m (0 ft)/year. Data from different 3D computational fluid mechanics models, typically with spatial resolution of 3 kilometres (1.9 mi) and depth each element equal to 1–10 metres (3.3–32.8 ft) are predominantly used in computer models. Before being given its present name,

5643-467: The Strait of Hormuz. Writing the water balance budget for the Persian Gulf, the inputs are river discharges from Iran and Iraq (estimated to be 2,000 cubic metres (71,000 cu ft) per second), as well as precipitation over the sea which is around 180 mm (7.1 in)/year in Qeshm Island . The evaporation of the sea is high, so that after considering river discharge and rain contributions, there

5742-576: The UK opened a permanent military base, HMS  Jufair , in the Persian Gulf, the first since it withdrew from East of Suez in 1971 and is developing a support facility in Oman. Eight nations have coasts along the Persian Gulf: Bahrain , Iran , Iraq , Kuwait , Oman , Qatar , Saudi Arabia , and the United Arab Emirates . The Persian gulf's strategic location has made it an ideal place for human development over time. Today, many major cities of

5841-472: The ability to pile up and accumulate due to the sediment traveling into a steep subduction trench rather than a shallow continental shelf . There are many other lesser factors that could explain why the majority of river deltas form along passive margins rather than active margins. Along active margins, orogenic sequences cause tectonic activity to form over-steepened slopes, brecciated rocks, and volcanic activity resulting in delta formation to exist closer to

5940-652: The addition of artificial islands for tourist attractions , such as The World Islands in Dubai and The Pearl Island in Doha . Persian Gulf islands are often also historically significant, having been used in the past by colonial powers such as the Portuguese and the British in their trade or as acquisitions for their empires. The Persian Gulf is connected to the Indian Ocean through

6039-1256: The basins feeding deltas have reduced river sediment delivery to many deltas in recent decades. This change means that there is less sediment available to maintain delta landforms, and compensate for erosion and sea level rise , causing some deltas to start losing land. Declines in river sediment delivery are projected to continue in the coming decades. The extensive anthropogenic activities in deltas also interfere with geomorphological and ecological delta processes. People living on deltas often construct flood defences which prevent sedimentation from floods on deltas, and therefore means that sediment deposition can not compensate for subsidence and erosion . In addition to interference with delta aggradation , pumping of groundwater , oil , and gas , and constructing infrastructure all accelerate subsidence , increasing relative sea level rise. Anthropogenic activities can also destabilise river channels through sand mining , and cause saltwater intrusion . There are small-scale efforts to correct these issues, improve delta environments and increase environmental sustainability through sedimentation enhancing strategies . While nearly all deltas have been impacted to some degree by humans,

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6138-422: The bird's-foot of the Mississippi or Ural river deltas), pushing its mouth into the standing water. As the deltaic lobe advances, the gradient of the river channel becomes lower because the river channel is longer but has the same change in elevation (see slope ). As the gradient of the river channel decreases, the amount of shear stress on the bed decreases, which results in the deposition of sediment within

6237-471: The book of Nearchus known as Indikê (300 BC), the word "Persikon kolpos" is mentioned for multiple times meaning "Persian gulf". During the years 550 to 330 BC, coinciding with the sovereignty of the Achaemenid Persian Empire over the Middle East area, especially the whole part of the Persian Gulf and some parts of the Arabian Peninsula , the name of "Persian ( Pars ) Sea" is widely found in

6336-450: The channel and a rise in the channel bed relative to the floodplain . This destabilizes the river channel. If the river breaches its natural levees (such as during a flood), it spills out into a new course with a shorter route to the ocean, thereby obtaining a steeper, more stable gradient. Typically, when the river switches channels in this manner, some of its flow remains in the abandoned channel. Repeated channel-switching events build up

6435-552: The coast of Iran (Persia)". This inland sea of some 251,000 square kilometres (96,912 sq mi) is connected to the Gulf of Oman in the east by the Strait of Hormuz ; and its western end is marked by the major river delta of the Shatt al-Arab , which carries the waters of the Euphrates and the Tigris . In Iran , this is called "Arvand Rud" (lit. Swift River ). Its length is 989 kilometres (615 miles), with Iran covering most of

6534-499: The compiled written texts. At the same period, there is the inscription and engraving of Darius the Great, which belongs to the fifth century BC: King Darius says: I ordered to dig this ( Canal of the Pharaohs ) canal from the river that is called Nile ( Pirâva ) and flows in Egypt ( Mudrâyâ ), to the sea that begins in Persia ( Pârsa ). Therefore, when this canal had been dug as I had ordered, ships went from Egypt through this canal to Persia, as I had intended. In Sassanian times,

6633-556: The economy due to their well-sorted sand and gravel . Sand and gravel are often quarried from these old deltas and used in concrete for highways , buildings, sidewalks, and landscaping. More than 1 billion tons of sand and gravel are produced in the United States alone. Not all sand and gravel quarries are former deltas, but for ones that are, much of the sorting is already done by the power of water. Urban areas and human habitation tend to be located in lowlands near water access for transportation and sanitation . This makes deltas

6732-410: The entire Gulf coast. For most of the early history of the settlements in the Persian Gulf, the southern shores were ruled by a series of nomadic tribes. During the end of the fourth millennium BC , the southern part of the Persian Gulf was dominated by the Dilmun civilization. For a long time, the most important settlement on the southern coast of the Persian Gulf was Gerrha . In the second century

6831-429: The fall of the Parthian Empire , the Sassanid Empire ruled the northern half and at times the southern half of the Persian Gulf. The Persian Gulf, along with the Silk Road , were important trade routes in the Sassanid Empire. Many of the trading ports of the Persian empires were located in or around Persian Gulf. Siraf , an ancient Sassanid port that was located on the northern shore of the Persian Gulf, located in what

6930-414: The flow enters the standing water, it is no longer confined to its channel and expands in width. This flow expansion results in a decrease in the flow velocity , which diminishes the ability of the flow to transport sediment . As a result, sediment drops out of the flow and is deposited as alluvium , which builds up to form the river delta. Over time, this single channel builds a deltaic lobe (such as

7029-506: The fresh stream feeding the head of tidal propagation. As a result, the tributaries are considered to be "subestuaries". The origin and evolution of a tidal freshwater delta involves processes that are typical of all deltas as well as processes that are unique to the tidal freshwater setting. The combination of processes that create a tidal freshwater delta result in a distinct morphology and unique environmental characteristics. Many tidal freshwater deltas that exist today are directly caused by

7128-466: The geomorphology and ecosystem. Deltas are typically classified according to the main control on deposition, which is a combination of river, wave , and tidal processes, depending on the strength of each. The other two factors that play a major role are landscape position and the grain size distribution of the source sediment entering the delta from the river. Fluvial-dominated deltas are found in areas of low tidal range and low wave energy. Where

7227-589: The governor of the Ottoman Vilayet of Baghdad , Midhat Pasha , the ruling Al Thani tribe submitted peacefully to Ottoman rule. The Ottomans were forced to withdraw from the area with the start of World War I and the need for troops in various other frontiers. In World War II , the Western Allies used Iran as a conduit to transport military and industrial supply to the USSR, through a pathway known historically as

7326-406: The lake bottom beyond this steep slope as more gently dipping bottomset beds. Behind the delta front, braided channels deposit the gently dipping beds of the topset on the delta plain. While some authors describe both lacustrine and marine locations of Gilbert deltas, others note that their formation is more characteristic of the freshwater lakes, where it is easier for the river water to mix with

7425-586: The lakewater faster (as opposed to the case of a river falling into the sea or a salt lake, where less dense fresh water brought by the river stays on top longer). Gilbert himself first described this type of delta on Lake Bonneville in 1885. Elsewhere, similar structures occur, for example, at the mouths of several creeks that flow into Okanagan Lake in British Columbia and form prominent peninsulas at Naramata , Summerland , and Peachland . In wave-dominated deltas, wave-driven sediment transport controls

7524-566: The land of the Indians is made by the Indus river no less than is the case with that of Egypt". As a generic term for the landform at the mouth of the river, the word delta is first attested in the English-speaking world in the late 18th century, in the work of Edward Gibbon . River deltas form when a river carrying sediment reaches a body of water, such as a lake, ocean, or a reservoir . When

7623-662: The local powers and the Ottoman Empire. Following the arrival of the English and the Dutch, the Safavid Empire allied with the newcomers to contest Portuguese dominance of the seas in the 17th century. Portuguese expansion into the Indian Ocean in the early 16th century following Vasco da Gama 's voyages of exploration saw them battle the Ottomans up the coast of the Persian Gulf. In 1521,

7722-457: The mangroves as a biological reserve was ignored by the emirate of Sharjah, which allowed the dredging of a channel that bisects the wetland and construction of an adjacent concrete walkway. Environmental watchdogs in Arabia are few, and those that do advocate the wildlife are often silenced or ignored by developers of real estate many of whom have governmental connections. Real estate development in

7821-556: The modern city of Behbahan in Khuzestan Province . This area was inhabited at the end of the fifth and beginning of the fourth millennia BC. The principal ancient site being excavated is Tol-e Chega Sofla , also known as Chogha Sofla. Chega Sofla represents the late Middle Susiana to Late Susiana periods of Iran. The C14 dates for Chega Sofla are currently 4,700-3,700 BC. To the north, the Behbahan plain, intersected by Marun River ,

7920-461: The most alarming sign is the "mass suicides" committed by dolphins off Iran's Hormozgan province, which are not well understood, but are suspected to be linked with a deteriorating marine environment from water pollution from oil, sewage, and industrial run offs. The Persian Gulf is home to over 700 species of fish, most of which are native. Of these 700 species, more than 80% are reef associated. These reefs are primarily rocky, but there are also

8019-423: The most lucrative world supply of oil, and the lack of cooperation between Arab states and Iran, have had a negative impact on the survival of many marine species, including dugongs. The Persian Gulf is also home to many migratory and local birds. There is great variation in color, size, and type of the bird species that call the Persian Gulf home. Concerns regarding the endangerment of the kalbaensis subspecies of

8118-405: The northern coast and Saudi Arabia most of the southern coast. The Persian Gulf is about 56 km (35 mi) wide at its narrowest, in the Strait of Hormuz. Overall, the waters are very shallow, with a maximum depth of 90 metres (295 feet) and an average depth of 50 metres (164 feet). Countries with a coastline on the Persian Gulf are (clockwise, from north): Iran; Oman 's Musandam exclave ;

8217-580: The onset of or changes in historical land use, especially deforestation , intensive agriculture , and urbanization . These ideas are well illustrated by the many tidal freshwater deltas prograding into Chesapeake Bay along the east coastline of the United States. Research has demonstrated that the accumulating sediments in this estuary derive from post-European settlement deforestation, agriculture, and urban development. Other rivers, particularly those on coasts with significant tidal range , do not form

8316-480: The result of this process is the Wax Lake Delta . In both of these cases, depositional processes force redistribution of deposition from areas of high deposition to areas of low deposition. This results in the smoothing of the planform (or map-view) shape of the delta as the channels move across its surface and deposit sediment. Because the sediment is laid down in this fashion, the shape of these deltas approximates

8415-573: The river delta, causing the delta to retreat. For deltas that form further upriver in an estuary, there are complex yet quantifiable linkages between winds, tides, river discharge, and delta water levels. Erosion is also an important control in tide-dominated deltas, such as the Ganges Delta , which may be mainly submarine, with prominent sandbars and ridges. This tends to produce a "dendritic" structure. Tidal deltas behave differently from river-dominated and wave-dominated deltas, which tend to have

8514-414: The river water is nearly equal in density to the basin water, the delta is characterized by homopycnal flow , in which the river water rapidly mixes with basin water and abruptly dumps most of its sediment load. Where the river water has a higher density than basin water, typically from a heavy load of sediment, the delta is characterized by hyperpycnal flow in which the river water hugs the basin bottom as

8613-399: The sediment is never piled up in thick sequences due to the sediment traveling and depositing in deep subduction trenches. At the mouth of a river, the change in flow conditions can cause the river to drop any sediment it is carrying. This sediment deposition can generate a variety of landforms, such as deltas, sand bars, spits, and tie channels. Landforms at the river mouth drastically alter

8712-514: The sediment source. When sediment does not travel far from the source, sediments that build up are coarser grained and more loosely consolidated, therefore making delta formation more difficult. Tectonic activity on active margins causes the formation of river deltas to form closer to the sediment source which may affect channel avulsion , delta lobe switching, and auto cyclicity. Active margin river deltas tend to be much smaller and less abundant but may transport similar amounts of sediment. However,

8811-814: The sediment supplied by the feeding river. Etymologically, the term river delta derives from the triangular shape (Δ) of the uppercase Greek letter delta . In hydrology , the dimensions of a river delta are determined by the balance between the watershed processes that supply sediment and the watershed processes that redistribute, sequester, and export the supplied sediment into the receiving basin. River deltas are important in human civilization , as they are major agricultural production centers and population centers. They can provide coastline defence and can impact drinking water supply. They are also ecologically important, with different species' assemblages depending on their landscape position. On geologic timescales , they are also important carbon sinks . A river delta

8910-424: The shape of the delta, and much of the sediment emanating from the river mouth is deflected along the coastline. The relationship between waves and river deltas is quite variable and largely influenced by the deepwater wave regimes of the receiving basin. With a high wave energy near shore and a steeper slope offshore, waves will make river deltas smoother. Waves can also be responsible for carrying sediments away from

9009-599: The southern shorelines. During the seventh century the Sassanid Persian empire conquered the whole of the Persian Gulf, including southern and northern shores. Between 625 BC and 226 AD, the northern side was dominated by a succession of Persian empires including the Median , Achaemenid , Seleucid and Parthian empires. Under the leadership of the Achaemenid king Darius the Great (Darius I), Persian ships found their way to

9108-437: The surface of the water, as the corals are to biological health of the Persian Gulf in deeper waters. Mangroves' ability to survive the salt water through intricate molecular mechanisms, their unique reproductive cycle, and their ability to grow in the most oxygen-deprived waters have allowed them extensive growth in hostile areas of the Persian Gulf. However, with the advent of artificial island development, most of their habitat

9207-650: The trailing edges of passive margins due to the majority of large rivers such as the Mississippi , Nile , Amazon , Ganges , Indus , Yangtze , and Yellow River discharging along passive continental margins. This phenomenon is due mainly to three factors: topography , basin area, and basin elevation. Topography along passive margins tend to be more gradual and widespread over a greater area enabling sediment to pile up and accumulate over time to form large river deltas. Topography along active margins tends to be steeper and less widespread, which results in sediments not having

9306-408: The waters off Qatar, Bahrain, UAE, and Saudi Arabia make the Persian Gulf the second most important habitat for the species, hosting some 7,500 remaining dugongs. However, the current number of dugongs is dwindling, and it is not clear how many are currently alive or what their reproductive trend is. Ambitious and uncalculated construction schemes, political unrest, ever-present international conflict,

9405-500: The world's natural gas reserves. The oil-rich countries (excluding Iraq ) that have a coastline on the Persian Gulf are referred to as the Persian Gulf States . Iraq's egress to the Persian Gulf is narrow and easily blockaded, consisting of the marshy river delta of the Shatt al-Arab , which carries the waters of the Euphrates and the Tigris rivers, where the east bank is held by Iran. River delta A river delta

9504-520: The world's largest population of Indo-Pacific humpbacked dolphins . One of the more unusual marine mammals living in the Persian Gulf is the dugong ( Dugong dugon ). Also called "sea cows", for their grazing habits and mild manner resembling livestock, dugongs have a life expectancy similar to that of humans and they can grow up to 3 metres (9.8 feet) in length. These gentle mammals feed on sea grass and are closer relatives of certain land mammals than are dolphins and whales . Their simple grass diet

9603-468: Was called Arosis ( ancient Greek Ἄροσις, Latin Arosis , also Zarotis, Oratis, Oroatis ). The river represented the border of the ancient territories of Parsa (Persides) , and Susiana . At the mouth of the river, the fleet of Nearchus (360–300 BC), an associate of Alexander the Great , stopped to rest and to take on water for five days to sail along the shores of Susiana. The town of Alexandria Carmania

9702-713: Was first coined by Alexander von Humboldt for the middle reaches of the Orinoco River , which he visited in 1800. Other prominent examples include the Inner Niger Delta , Peace–Athabasca Delta , the Sacramento–San Joaquin River Delta , and the Sistan delta of Iran. The Danube has one in the valley on the Slovak–Hungarian border between Bratislava and Iža . In some cases, a river flowing into

9801-617: Was founded by Alexander in January 324 BC after his army had reunited with Nearchus and his men who had beached their boats near the mouth of the Minab River , further down along the south coast of Iran in Hormozgan province . The Zohreh Prehistoric Project is a long-term archaeological study program launched in 2015, and focusing on the Zohreh River plain. The research continues in the area south of

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