A river delta 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 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.
71-555: Kuttanad is a river delta landscape region in the state of Kerala , India, known for its vast paddy fields and geographical peculiarities. It is in the Districts of Alappuzha, Kottayam and Pathanamthitta. The region has the lowest altitude in India, and is one of the few places in the world where farming is carried on around 1.2 to 3.0 metres (4 to 10 ft) below sea level,, using rice paddies largely located on reclaimed land amid
142-432: 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
213-433: A Ponnada, he presented "Ponnada Vaakkaal" (Ponnada by word). Thereafter his house was known as Ponnadavaakkaal. From 1920 to 1940 reclamation activity came to a halt because of a steep drop in the price of rice. Due to the steep decline in the price of rice between 1920 and 1940 reclamation activities slowed down, but they gained momentum again in the early 1940s. During this period, in order to increase agricultural output,
284-493: 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
355-545: 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
426-533: 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
497-399: 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
568-545: 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
639-436: A government initiated "Grow More Food" campaign and the provision of incentives encouraged new reclamations. The advent of electric motors made reclamation relatively easier, cheaper and less risky as compared to in earlier periods. The last tract of the reclamations namely Q, S and T block were made during this period by Joseph Murickan (Muricken Outhachan) and his wife's family Puthanppura Panchara (Veliyanadu). As farming in
710-583: A halt because of the ban on kayal reclamation imposed by the Madras Government in 1903. Cherukali Kayal, Rajapuram Kayal, Aarupanku Kayal, Pantharndu Panku kayal and Mathi Kayal were the other major reclamations during this period. In 1912, the Madras Government approved a proposal from the Travancore Government for further reclamations in three stages. Under this scheme kayal land was notified for reclamation in blocks each named with
781-415: A high literacy rate, 96.01%, higher than the state average of 94%. Niranam is mentioned in the writings of Pliny and Cosmas Indicopleustes as a trade centre where pepper grows and is known to have a variety of different settlers from Greeks to Aryan Jains . Geologists suggest that the sea retracted from this area due to some major geographical changes. Niranam St Mary's Orthodox Cathedral has been
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#1732772235628852-573: 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
923-607: A letter of the English alphabet. Out of the total area of 19,500 acres of kayal land, 12,000 acres were reclaimed between 1913 and 1920. After the removal of the ban in 1913, Pallithanam Luca Matthai along with some other prominent families in Kuttanadu, reclaimed E-Block Kayal measuring a total area 2,400 acres. This is the biggest Kayal Nilam in Kuttanadu. C.J. Kurian, Ex MLC and Mr. John Illikalam were his main partners in this venture. The reclamations between 1914 and 1920, known as
994-439: 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
1065-423: 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
1136-447: 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
1207-551: 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
1278-602: Is a major sign that Mars once had large amounts of water. Deltas have been found over a wide geographical range. Below are pictures of a few. Niranam Niranam is a village in Thiruvalla , Kerala , India. It was a port in ancient Kerala, on the confluence of the Manimala and Pamba River . It is almost 7 km from Tiruvalla SCS Junction in Pathanamthitta District of Kerala, lies to
1349-462: Is a very important place for the Christians. Pattamukkil Tharavad at niranam is surrounded from three sides of niranam church . Priests From Pattamukkil families used to stay there and done priesthood and governed niranam church and its properties at the ancient days. As a result of the flood of 1341, the soil of nearby areas of Niranam is still sandy and resembles beaches, though not close to
1420-653: Is broadly determined to be between first century BC and 2nd century AD. His queen was Veliyan Nallini, the daughter of Veliyan Venman. Uthiyan Cheralathan was a contemporary of the Chola ruler Karikala Chola . He is praised for his elephant corps and cavalry. Present day Changanacherry end of Kuttanad was the capital of the Chera dynasty king Uthiyan Cheralathan . The native place of the Kuttuva tribe came to be known as Kuttanadu. According to sangam literature, Uthiyan Cheralathan
1491-591: 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
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#17327722356281562-472: Is farming, with rice the most important agricultural product. This activity gives the area its moniker of "The Rice Bowl of Kerala". Large farming areas near Vembanad Lake were reclaimed from the lake. The history of paddy cultivation in Kuttanad can be traced back centuries. The evolution of paddy cultivation correlated with technological advancement and changes in the regulatory framework that existed during
1633-533: Is obtained from the Sangam period literature. According to the Sangam era texts, Uthiyan Cheralathan (' Perum Chorru Udiyan Cheralathan , Athan I or Udiyanjeral ) is the first recorded Chera dynasty ruler of the Sangam period in ancient Kerala . He had his capital at a place called Kuzhumur in Kuttanad (central Kerala ) and expanded the kingdom northward and eastward from his original homeland. His lifetime
1704-548: 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
1775-662: 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
1846-532: 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
1917-572: The Travancore Maharajah Moolam Thirunal . Three distinct stages can be identified in the reclamation of kayal lands from the lake. The first stage was carried out by private entrepreneurs without any financial support from the government. The Pattom Proclamation made by the Travencore Kingdom in 1865, gave a great fillip to reclamation activities between 1865 and 1888. During this period de-watering of
1988-629: The 19th and 20th centuries. In earlier times, reclamation was carried out mainly from the shallow part of the Vembanad Lake or from the periphery of the Pamba River . These reclamations constituted small areas of paddy fields called padasekharams . Bailing out of water from the fields were done manually using water wheels called chakram . Gradually the manual method used for bailing out of water gave way to steam engines. There were robberies in Kuttanad in earlier days, which were prohibited by
2059-700: 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
2130-503: 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
2201-573: The Sree Vallabha Temple, it also housed a Vedic school system. The temple is in a very old condition, and measures are taken to renovate it. It is believed to be one of the "108 Shiva Temples" established by Parasurama in Kerala by tradition. It is believed to be one of the oldest churches in Kerala and thus in India as well as among the oldest ones in the world. The architecture shows striking similarities to ancient temple architecture. It
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2272-592: The State Highway 12, and State Highway 6. The village lies west to Tiruvalla city centre, about 7 kilometres. The railway station is about 8 km from Niranam, in Tiruvalla city, adjacent to the Mallappally Road, near Kuttappuzha RSPO. Niranam, being an old settlement of both Brahmanic and Christian people, has a composite culture and historical buildings. This is a very old Shiva temple. Like
2343-472: 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
2414-418: The area increased, farmers felt themselves constrained by the two cycles a year for rice cultivation. The reason for which is the limited availability of potable water in Kuttanadu. During the monsoon seasons, the water from the mountains flow through the rivers to the sea, bringing potable water to Kuttanadu. But during summer, due to the low level of the region seawater enters Kuttanadu, significantly increasing
2485-1256: 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,
2556-422: 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
2627-838: The bund the salt water tended to cleanse the backwaters, but this no longer occurs, leading to pollution of the backwaters and the nearby land. Kuttanad assembly constituency was a part of Alappuzha . After the Lok Sabha delimitation in 2008, it now belongs to the Mavelikkara constituency. River delta 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
2698-482: The burnt forest), was eventually called Kuttanad. Until the recent past burned black wooden logs were mined from paddy fields called as ‘Karinilam’(Black paddy fields). This fact substantiates the theory of Chuttanad evolving to Kuttanad. Ramankary, Puthukkary, Amichakary, Oorukkary, Mithrakary, Mampuzhakary, Kainakary, Chathurthiakary, Thakazhy, Edathua, Chambakkulam, Mankombu and Chennamkary are some familiar place names in Kuttanad. The first recorded history of this land
2769-450: 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
2840-580: The delta. Kuttanad is historically important in the ancient history of South India and is the major rice producer in the state. Farmers of Kuttanad are famous for Biosaline Farming. The United Nations Food and Agriculture Organization (FAO) has declared the Kuttanad Farming System as a Globally Important Agricultural Heritage System (GIAHS) in 2013. Four of Kerala's major rivers, the Pamba , Meenachil , Achankovil and Manimala flow into
2911-619: 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
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2982-409: The first two phases were complete the entire money allotted for the project ran out and left the final phase in limbo. The farmers who were expecting many financial benefits after the completion of the project decided to take matters into their own hands and one night in 1972, a large group of farmers filled the gap between the north and the south side with earth. To this day, the earth embankment between
3053-414: 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
3124-506: 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
3195-466: 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
3266-406: 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
3337-594: 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
3408-583: 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
3479-408: The leadership of Pallithanam Luca Matthai , Cunnumpurathu Kurien, Vachaparampil Mathen, Pazhayaparmpil Chacko, Kunnathusseril Peious, Ettuparayil Xavier and Pattassery PP Mathai. During the third period of new reclamation, R Block Kayal covering 1,400 acres was reclaimed by the joint efforts of eight families led by then member of Sree Moolam Popular Assembly, Pallithanam Luca Matthai . His partners in
3550-493: The new reclamations, were carried out in three periods. In the first period Blocks A to G measuring 6300 Acres were reclaimed. C Block, D Block (Attumukham Aarayiram (Attumuttu Kayal), Thekke Aarayiram and Vadakke Aarayiram) and E Block (Erupathinalayiram Kayal) F Block (Judge's Aarayiram Kayal) and G Block (Kochu Kayal) are the major Kayal Nilams reclaimed during this period. During the second period of new reclamation, blocks H to N covering an area of 3600 acres were reclaimed under
3621-524: 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
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#17327722356283692-593: The polders was done manually using chakram , which restricted large-scale reclamation. Only about 250 hectares of land were reclaimed during this period. Venadu kayal and Madathil Kayal were reclaimed during this period and are considered the first "Kayal Nilams" to be reclaimed from the Vembanad Lake. These pioneering reclamation activities in kayal cultivation were made by the two brothers Mathai Luka Pallithanam and Ouseph Luka Pallithanam from Kainady village in Kuttanadu. The second phase started during 1888. One of
3763-485: The reclamation during this period was undertaken by Chalayil Eravi Kesava Panicker. He chose to reclaim Vembanad kayal from the mouth of the Chennamkari river as it joins with the back waters. The reclaimed kayal was known as ‘ Attumuttu Kayal’. Other major reclamation on the same year was Seminary Kayal which was undertaken by Kottayam Orthodox Seminary. The introduction of kerosene engines for dewatering resulted in
3834-487: The reclamation included Vachaparampil Mathen, Pazhayaparmpil Chacko, Ettuparayil Xavier, Pattassery PP Mathai, Kaarikkuzhi Ponnada Vaakkaal Mathulla Mappila (E & F block), Meledom, Paruthickal and Kandakudy. Once, while the king of travancore visited the Erupathinalayiram Kayal he was pleased and told Kaarikkuzhi Mathulla Mappila that he should have bought a Ponnada to honor him. Since he has not bought
3905-465: The reclamation of wider areas of the lake for cultivation. This made farmers consider venturing into the deeper parts of the lake. During the period between 1898 and 1903, reclamation activity was led by Pallithanam Luca Mathai (alias Pallithanathu Mathaichen) who reclaimed the Cherukara Kayal and Pallithanam Moovayiram Kayal. But the second phase (1890 to 1903) of reclamation activities came to
3976-547: The region. It is well known for its boat race in the Punnamada Backwaters, known in Malayalam as Vallamkalli . Kuttanad has no recorded history on the origin of the land. But a blend of myths and legends is transferred from generation to generation orally among local people. Kuttanad was once believed to be a wild forest with dense tree growth which was destroyed subsequently by a wild fire. Chuttanad (place of
4047-487: 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
4118-579: 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
4189-414: 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
4260-432: The salinity of the water and making it unpotable. Kuttanad is also recognised as a Globally Important Agricultural Heritage Systems (GIAHS) by FAO . Thottappally Spillway project was designed as a permanent solution to the flood situation in Kuttanad. This programme was envisaged in such a way that flood waters from Pamba, Manimalayar and Achankovil were diverted to the sea before it reached Vembanad lake. The spillway
4331-480: The seat of the various Malankara metropolitans. The Niranam poets , the "Kannassas" are credited to be pioneers in Malayalam bhakti literature, they authored Bhagavata, Ramayana, and Bharata in Malayalam. They lived in the 14th century CE. The great flood of 1341 AD helped to shift the sea westwards from silt filling in the direct sea route from Niranam. Niranam is a quiet place, lying between Kadapra to East and Neerettupuram to North. It can be approached through both
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#17327722356284402-399: 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
4473-514: 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,
4544-424: 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
4615-399: The staple food of the people of the region require a small amount of salt water for its breeding. The bund has caused deterioration of fish varieties in the region and the fishermen opposed to the bund as of 2005. The bund has also disrupted the harmony of the sea with the backwaters and has caused problems not foreseen before the bund like the omnipresence of the water weeds. Before creation of
4686-656: 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
4757-540: The two sections of the bund remains. With this, it was possible to close the regulator of shutters during December–June when the saline water enters, and then open it during monsoon. Once the Thanneermukkam bund and spillway became operational two crops were possible in Kuttanad. Even though the bund has improved the quality of life of the farmers, the bund is alleged to have caused severe environmental problems. The backwaters which were abundant with fish and part of
4828-544: The western part of Tiruvalla, identified as Upper Kuttanad region. It Is Part Of Thiruvalla Sub-District.Also Comes Under Thiruvalla Constituency.It is identified with Nelcynda in Periplus of the Erythraean Sea . Niranam is a large village located in the west of Tiruvalla, with 2837 families residing. The population of Niranam area is 10070, average sex ratio is 1118, higher than the state average of 1084. Niranam has
4899-460: Was commissioned in 1955. In 1968, the Government of India proposed that a bund ( Dam ) be made across the river so that seawater would not be allowed to come inside Kuttanad during summer, allowing farmers to cultivate an extra crop per year. The project was planned in three phases, the south side, the north side and another phase to join the two sections. The project was delayed and by the time
4970-2178: Was defeated in the Battle of Venni against Karikala Chola and the capital was burnt down. The Kuttanad region is categorised into: Lower Kuttanadu comprises taluks of Ambalapuzha , Nedumudy , Kuttanadu (excluding Edathua , Thalavady , Kidangara and Muttar ), and the northern half of Karthikapally taluk in Alappuzha district . Upper Kuttanad comprises Veeyapuram and Pallippad in Karthikapally taluk, Edathua , Thalavady , Kidangara and Muttar in Kuttanad taluk; Chennithala and Thripperumthura villages in Mavelikkara taluk; Mannar , Kurattissery , Budhanoor , Ennakkad villages in Chengannur taluk of Alappuzha district ; and Parumala , Kadapra , Niranam , Pulikeezhu, Nedumpuram , Chathenkary , Peringara , and Kavumbhagam villages in Pathanamthitta district . North Kuttanad comprises Vaikom taluk, western parts of Kottayam taluk, and western parts of Changanacherry taluk in Kottayam district . Kuttanad's major villages include Kainakary , Chathenkary , Ramankary , Puthukkary , Chennamkary , Nedumudi , Niranam , Kaipuzha , Edathua , Mampuzhakkary , Neelamperoor , Kainady , Kavalam , Pulincunnoo , Manalady, Kannady Kayalpuram, Veliyanadu, Veeyapuram , Vezhapra, Kunnamkary, Kumaramkary , Valady , Kidangara, Mithrakary , Muttar , Neerattupuram , Thalavadi , Changankary, Champakulam , Nedumudi , Moonnatummukham, Melpadom, Pulincunnu , Pallippad , Payippad , Karichal, Ayaparambu, Anary, Vellamkulangara, Pilappuzha, Pandi, Edathua , Pacha, Chekkidikad, Thakazhy , Cheruthana , Karuvatta , Chennithala , Narakathara , Venattukad, Kayalppuram, Mankompu , Chathurthiakary, Koduppunna , Oorukkary, Thayankary, Thiruvarpu , Kumarakom, Arpookara , Pullangadi, Payattupakka, and Kandankary . The major occupation in Kuttanadu
5041-732: 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
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