Hydrography is the branch of applied sciences which deals with the measurement and description of the physical features of oceans, coastal areas and rivers, as well as with the prediction of their change over time, for the primary purpose of safety of navigation and in support of all other marine activities, including economic development and defence, scientific research, environmental protection. The origins of hydrography lay in the making of charts to aid navigation, by individual mariners as they navigated into new waters; these were the private property closely held secrets, of individuals who used them for commercial or military advantage. As transoceanic trade and exploration increased, hydrographic surveys started to be carried out as an exercise in their own right, the commissioning of surveys was done by governments and special hydrographic offices. National organizations navies, realized that the collection and distribution of this knowledge gave it great organizational and military advantages.
Thus were born dedicated national hydrographic organizations for the collection, organization and distribution of hydrography incorporated into charts and sailing directions. Prior to the establishment of the United Kingdom Hydrographic Office, Royal Navy captains were responsible for the provision of their own charts. In practice this meant that ships sailed with inadequate information for safe navigation, that when new areas were surveyed, the data reached all those who needed it; the Admiralty appointed Alexander Dalrymple as Hydrographer in 1795, with a remit to gather and distribute charts to HM Ships. Within a year existing charts from the previous two centuries had been collated, the first catalogue published; the first chart produced under the direction of the Admiralty, was a chart of Quiberon Bay in Brittany, it appeared in 1800. Under Captain Thomas Hurd the department received its first professional guidelines, the first catalogues were published and made available to the public and to other nations as well.
In 1829, Rear-Admiral Sir Francis Beaufort, as Hydrographer, developed the eponymous Scale, introduced the first official tide tables in 1833 and the first "Notices to Mariners" in 1834. The Hydrographic Office underwent steady expansion throughout the 19th century; the word hydrography comes from the Ancient Greek ὕδωρ, "water" and γράφω, "to write". Large-scale hydrography is undertaken by national or international organizations which sponsor data collection through precise surveys and publish charts and descriptive material for navigational purposes; the science of oceanography is, in part, an outgrowth of classical hydrography. In many respects the data are interchangeable, but marine hydrographic data will be directed toward marine navigation and safety of that navigation. Marine resource exploration and exploitation is a significant application of hydrography, principally focused on the search for hydrocarbons. Hydrographical measurements include the tidal and wave information of physical oceanography.
They include bottom measurements, with particular emphasis on those marine geographical features that pose a hazard to navigation such as rocks, shoals and other features that obstruct ship passage. Bottom measurements include collection of the nature of the bottom as it pertains to effective anchoring. Unlike oceanography, hydrography will include shore features and manmade, that aid in navigation. Therefore, a hydrographic survey may include the accurate positions and representations of hills and lights and towers that will aid in fixing a ship's position, as well as the physical aspects of the sea and seabed. Hydrography for reasons of safety, adopted a number of conventions that have affected its portrayal of the data on nautical charts. For example, hydrographic charts are designed to portray what is safe for navigation, therefore will tend to maintain least depths and de-emphasize the actual submarine topography that would be portrayed on bathymetric charts; the former are the mariner's tools to avoid accident.
The latter are best representations of the actual seabed, as in a topographic map, for scientific and other purposes. Trends in hydrographic practice since c. 2003–2005 have led to a narrowing of this difference, with many more hydrographic offices maintaining "best observed" databases, making navigationally "safe" products as required. This has been coupled with a preference for multi-use surveys, so that the same data collected for nautical charting purposes can be used for bathymetric portrayal. Though, in places, hydrographic survey data may be collected in sufficient detail to portray bottom topography in some areas, hydrographic charts only show depth information relevant for safe navigation and should not be considered as a product that portrays the actual shape of the bottom; the soundings selected from the raw source depth data for placement on the nautical chart are selected for safe navigation and are biased to show predominately the shallowest depths that relate to safe navigation.
For instance, if there is a deep area that can not be reached because it is surrounded by shallow water, the deep area may not be shown. The color filled areas that show different ranges of shallow water are not the equivalent of contours on a topographic map since they are drawn seaward of the actual shallowest depth portrayed. A bathymetric chart does show marine topology accurately. Details covering the ab
The Kabini called Kapila, is one of the major tributaries of the river Cauvery in southern India. It originates in the Wayanad District of Kerala state by the confluence of the Panamaram River and the Mananthavady River, it flows eastward to join the Kaveri River at Tirumakudalu Narasipura in Karnataka. Close to the town of Sargur it forms the huge Kabini Reservoir; the backwaters of the Kabini reservoir are rich in wildlife in summer when the water level recedes to form rich grassy meadows. The Kabini dam is 2,284 ft in length with an original gross storage of 19.52 tmcft. The Kabini Dam is situated between villages Bichanahalli and Bidarahalli having distance of 17 km 6 km away from Sargur town in Heggadadevana kote taluk, Mysore district, Karnataka; the Kabini Forest Reserve is one of the most popular wildlife destinations of Karnataka because of its accessibility, lush green landscape surrounding a large lake, sightings of herds of elephants, tigers. It is 80 km away from Mysuru and 205 km from Bengaluru, comprises the south-eastern part of Nagarahole National Park.
Situated on the banks of the Kabini River, the reserve is spread over 55 acres of forestland, steep valleys, water bodies. Once a private hunting lodge of the Maharaja of Mysore, Kabini was a popular shikar hotspot for British Viceroys and Indian royalty. Now it is considered to be one of the best Wildlife National Parks in India, famous for its spectacular wildlife and bird life. There are around 120 tigers, 100+ leopards, Four types of deer, Sloth bear, Indian Gaurs and elephants in the Nagarahole National Park; the river originates in the Pakramthalam hills at Kuttiady-Mananthavady road. Makkiyad river and Periya river join it near Valad respectively. After flowing through Mananthavady town, Panamaram river joins Kabini near Payyampally. One branch of the Panamaram river starts from the Banasura Sagar reservoir near Padinjarethara and the other branch of the river start from Lakkidi hills. After traversing 2 kilometres from the confluence of Panamaram river Kabini forms an island called Kuruva Island, spreading over 520 acres with diverse flora and fauna.
Within 20 km it reaches the Kabini reservoir bordering Karnataka for some distance. Between Kabani reservoir and Kuruva island Kalindi river joins Kabini. Kalindi river originates from Brahmagiri hills which on reaching near Thirunelli Temple the rivulet Papanasini joins it. Taraka and Nugu are the two small rivers in Heggadadevana kote taluk; the Kabini dam is built on the River Kabini in the district of Mysore. The dam is 696 meters in length and was built in 1974; the exact location of the dam is in Taluk Heggadadevanakote. The catchment area of the dam is 2,141.90 km2. It caters to the needs of around 22 villages and 14 hamlets and a prominent source of drinking water to Bengaluru. Further significant amount of water is discharged to the Mettur reservoir in Tamilnadu to fulfill the state's needs; this dam provides water to the combined system of Sagaredoddakere and Upper Nugu Dams. There is an arrangement of lifting and transfer of 28.00 TMC of water during the monsoons months from the Kabini dam to the other two smaller dams.
The dam is spread over an area of 55 hectares covering forests, rivers and valleys
The Meenachil River flows through the heart of Kottayam district of Kerala state, India. The river, 78 kilometres long, flows through Poonjar, Erattupetta, Palai and Kottayam before emptying itself into the Vembanad Lake at Kumarakom, the famous tourist place of Kerala; the Meenachil River is formed by several streams originating from the Western Ghats. The general elevation ranges from 77 m to 1156 m in the high lands and less than 2 m in the lowlands and 8 to 68 m in the midlands; the Meenachil has a watershed area of 1208.11 km². The river has a total annual yield of 2,349 million cubic metre and an annual utilizable yield of 1110 million cubic metre; the river has 38 tributaries including minor ones. The river has 114 micro watersheds; the river finds mention in The God of Small Things. The 78 kilometer long Meenachil river is the holy river in Kottayam district, it is called Gauna Nadi and Valanjar. The name Meenachil comes from Goddess Meenakshi of Madurai, the deity of the ruling Karthas of Meenachil.
Meenakshi became Meenachi and Meenachil. According to legends this river starts from the Kamandalu of great sage Gauna Maharshi like the river Kaveri from Agasthya Maharshi's Kamandalu. Hence this river got the name Gauna Nadi. Gauna Maharshi filled his Kamandalu with Sapthanadi Theertham. A beautiful idol of Lord Subrahmanya was kept in his kamandalu, he was eagerly waiting for the Darshan of Lord Sree Rama in his return journey to Ayodhya after killing Ravanan. Sree Raman was accompanied by large number of devotees like Vibhishanan and Angada in the Pushpaka Vimana. So Maharshi Gauna could not see Sita Devi properly. So the angry Gauna threw the kamandalu away and the idol of Subrahmanya Swami came out; these incidents occurred on a hill and since the hill is known as Kudamuruttimala. This flow of water became a river and thus the present Gauna nadi was formed. Along with the flow of the water, the idol was carried away to the Vishnu kshetram in Kidangoor and was installed in a new sreekovil; this is the present Kidangoor Subrahmanya Swami Temple.
So the water in Gauna river is as holy as the Sapthanadi Teertham. Sree Rama and Sitha Devi gave darshan to Gauna Maharshi. Rama advised Gauna Maharshi to continue his Tapas. Gauna Maharsi started his journey along the river bank and at last reached a beautiful village and decided to stay there, he attained moksha. After that this place became a great forest; this place is now famous as Kadappattor and the idol of Shiva worshipped by Gauna Maharshi is now famous as Lord Kadappattoorappa. Narada Maharshi, Veda Vyasa Maharshi, Pancha Pandavas and Panchali were associated with this river. Kavanar is the Malayalam equivalent for Gauna nadi. Arattu of many temples in Kottayam district is being carried out in this river; some of these temples are Bharananganam, Puliyannoor, Kidangoor, Amayannoor and Kumaranalloor. It flows through the Kidangoor and Kumaranalloor Brahmin gramams and through the taluks of Meenachil and Kottayam. Another legend associated with Meenachil river is that those who get Neelakkoduveli from this river in the month of Karkkidakam will become wealthy.
Only the Brahmins staying on the northern side of the Meenachil river were allowed to attend the Murajapam in Sree Padmanabha Swami Temple, Trivandrum The Kerala State Electricity Board has constructed two tunnels near Wagamon to divert the water from the Meenachil to the Idukki Dam. One is from the other from Koottiyar to Kappakkanam; the Kerala Government has accorded high priority to the implementation of the Meenachil River Valley Project. The project aims at diverting excess water from the Moovattupuzha river into the Meenachil River basin by constructing a tunnel from Arakkulam to Melukavu. Once implemented the project will help in increasing the availability of water in the area. There are a few serious issues affecting the environment of the Meenachil river basin; some of them are: Water pollution due to disposal of urban and domestic waste into the river all through the banks of the river at urban centers like Erattupetta, Palai and Kottayam. Uncontrolled legal and illegal mining of river sand leading to depletion of water table.
Illegal construction of numerous check dams. Diversion of upstream water to Idukki dam from the Vazhikkadavu Mini Dam. Illegal fishing, destroying marine life. Excavation of clay and sand from paddy fields for the brick and construction industries; the river is mentioned in the Booker Prize winning book "The God of Small Things" by Arundhati Roy. The story is centred on the Aymanam village. Meenachil river is the major river in Kottayam district and lakhs of people and many major towns and cities like Erattupetta, Palai and Kottayam depend on this river for drinking water and water for commercial activities. In earlier days when road transport was not developed much, kettuvalloms used to transport goods through Meenachil up to 2 km above Erattupetta and take agricultural products like copra to Alleppy port. Thousands of farmers use water from the river for agriculture, it is the natural channel for the discharge of rain water into the sea from eastern hills of Kottayam dist. In its banks have come up major cities and commercial centres which are cradles of the culture of this area of Travancore.
Meenachil river water enters the Vembanad lake before reaching the sea and has a major sh
Chalakudy River or Chalakudy Puzha is the fifth longest river in Kerala, India. The river flows through Thrissur District and Ernakulam District of Kerala; the total drainage area of the river is 1704 km². out of this 1404 km² lies in Kerala and the rest 300 km² in Tamil Nadu. The length of the river is 145.5 km. Though Chalakudy river in strict geological sense is a tributary of the Periyar river, for all practical purposes it is treated as a separate river by Government and other agencies; the River has gained its name, since it flows along the banks of the Chalakudy Town, the major settlement along the course of the river. The river though has its origin in the Anamalai region of Tamil Nadu, is a collection of some major tributaries originated from Parambikulam, Sholayar and Anakayam in Kerala. Chalakudy River is the one of few rivers of Kerala with relics of riparian vegetation in substantial level; the annual report of the National Bureau of Fish Genetic Resources Lucknow, mentioned that the Chalakudy River is the richest river in fish diversity in India.
The riparian forests of the Chalakudy River have revealed the existence of a thick riparian vegetation of more than 10 metres width for a distance of 10.5 km downstream from Peringalkuth, covering an area of 58.5 hectares. Out of this, 26.4 hectares lie within the Vazachal area, including three large islands densely covered by riparian forests. The riparian forests of the area have been found to be characterised by the presence of typical riparian species of plants, in addition to evergreen and semi-evergreen species. Out of the 319 species of flowering plants identified from the study area, 24 are endemic species of the Western Ghats and 10 are rare and endangered; the Chalakudy River is known for its diversity, as it contains 98 species of fresh water fishes out of the 152 species known from Kerala. Among these, 35 are endemic species of the Western Ghats and 31 are either vulnerable, endangered or critically endangered from indiscriminate collection for the aquarium fish trade, pollution and introduced species.
According to a report of the National Bureau of Fish Genetic Resources in Lucknow, Chalakudy could well be the richest river in fish diversity in India, with thick vegetation on both sides. Among the fish species in the river, the most species rich family are the Cyprinids, followed by Bagrid catfishes and hillstream loaches. Among others, Horabagrus nigricollaris and Sahyadria chalakkudiensis are endemic to the Chalakudy River; the famous waterfalls, Athirappilly Falls and Vazhachal Falls, are situated on this river. The hydro electric projects on Chalakkudy River are Sholayar Hydro Electric Project and Peringalkuttu Hydro Electric Project. For irrigation purposes Thumboormoozhy Dam is constructed across this river, it merges with the Periyar River near Elenthikara, adjacent to Manjali, North Paravur in Ernakulam District and Joins Kodungallur Backwaters and Join Arabian sea at Azhekode. The Parambikulam Dam has been built on one of its four tributaries. "Infobox facts". All Kerala River Protection Council.
Retrieved 30 January 2006. Study of rivers in Kerala Chalakudy River Protection Forum Chalakudy Puzha Samrakshana Samithi Dam Has Kerala Greens Up In Arms, Sep 22, 2007, Tehelka Magazine
The Anjarakandi River is one of two major rivers that flow through the Kannur District of Kerala, India. The river originates from the bottom of Kutimalai in the protected forest areas of Kannur district, it travels for flowing in west direction. The river starting from Kutimalai, a small spring flows through Perumbupattu, about four kilometers into the forest; the river collapses at 60 meters. Around 14 km again flows through the forest, it goes to the locality near the village of Doda. The river Anjarakandy is flowing through the Anjarakandy village of Kannur district; this place is prominent for its Cinnamon estate
Muvattupuzha is a prominent old town in the midlands directly to the east of Kochi. It is situated at around 40 km from downtown Kochi; the town is a growing urban centre in central Kerala and an aspiring new district headquarter. The town is popular as the starting point of Muvattupuzha river which happens by the merging of three rivers – namely Thodupuzhayar and Kothayar – to form Muvattupuzhayaar. Thus, this Thriveni Sangamam or confluence of three rivers is called Muvattupuzha. Muvattupuzha is a municipality in the eastern side of Ernakulam district in the Indian state of Kerala; the town is bordered by Kottayam district on southern side and Idukki district on eastern side 20 km from the town. Muvattupuzha lies on the intersection between M C Road and National Highway 49, about 42 km from district capital Ernakulam, it is the second biggest commercial centre of the district and one of the biggest in the central part of the state. The town is named after the Muvattupuzha river; the name is made up of three Malayalam words: Moonnu.
Aaru is a word, used for rivers in the southern half of Kerala, while the term puzha is used in the northern parts. The three rivers in this case are the Kothamangalam river or Kothayaar and Thodupuzhayar, which merge to form a single river called Muvattupuzhayar; this place is called Thriveni Sangamam in Malayalam which means the point of confluence of three rivers. In English both spellings viz. Moovattupuzha are interchangeably used. Etymologically Moovattupuzha, is the correct spelling how commoners use the spelling Muvattupuzha and is better accepted. Muvattupuzha was part of the Vadakkumkoor Kingdom. Old documents show that parts of the lands of Muvattupuzha belonged to Edappally Swaroopam, but were transferred to Manas'. After Indian Independence, from 1949 to 1956, Muvattupuzha was a part of the Kottayam district in Travancore-Cochin state. In 1956, when Kerala state was formed, Muvattupuzha remained as a part of Kottayam district until 1958, when Ernakulam district was formed on 1 April 1958.
Muvattupuzha, as a village union, came under the control of a council of three members nominated by the Government. V. P. Govindan Nair was the first president of the village union. By 1953, Muvattupuzha was declared a Panchayat. Kunnappillil Varkey Vaidyan was the first president of the elected Panchayat Committee. Muvattupuzha was raised to the status of a Municipality in the year 1958. N. Parameshwaran Nair became the first Municipal Chairman. Muvattupuzha made history as the first Municipality where the Communist Party came to power in a general election. N. P. Varghese was the first elected M. L. A. from Muvattupuzha Assembly Constituency. He defeated Manjunatha Prabhu of Communist party. K. M. George, founder of Kerala Congress represented Muvattupuzha; the first M. P. of Muvattupuzha was George Thomas Kottukapally. Of all the Municipal Chairmen of the town, P. P. Esthose deserves special mention, he was an MLA and the Municipal Chairman of Muvattupuzha. He got state-level recognition as the Chairman of Chamber of Chairmen.
In its entire history, he is the only Communist member elected to the Parliament from the constituency. St. Thomas, the Apostle of Jesus Christ who introduced Christianity to India, is believed to have visited this region; the Marth Mariam Syro-Malabar Catholic Church of Arakuzha has a recorded history of over 1000 years, making it one of the oldest Syrian churches in Kerala. It is known for its sculptures. Muvattupuzha was known as Arakuzha Pakuthi; as of 2001 India census, Muvattupuzha had a population of 29,230. Males constitute 49% of the population and females 51%. Muvattupuzha has an average literacy rate of 84%, higher than the national average of 59.5%: male literacy is 85%, female literacy is 82%. In Muvattupuzha, 11% of the population is under 6 years otf age. Malayalam and English are the official Languages. Hindi is spoken and understood due to the influx of migrant labors from North India; the region has Syrian Christians and Muslims. According to the 2011 census,Hindus consist of 39.91% muslim consist of 38.82% and christianity 21.10% of the total population Kavumpady Road in the heart of the town contains major Agraharam of Kerala Iyers.
Konkanis are in lesser numbers. Hindus are majority in the region with castes like Nair, Ezhava and Pulayar present around the Taluka. Syrian Christians include a majority of Syro-Malabar Catholics and Jacobites. There are Orthodox, Syro-Malankara Catholics and Evangelists also. Muvattupuzha is the seat of Muvattupuzha diocese of Malankara Jacobite Syriac Orthodox Church and Kandanad East diocese of Orthodox. Mappila Muslims make up most of the Muslim population. Hanafi sect called Thulukkar are concentrated near Post office Junction. Muslims include Ahmediyya; the town and western parts of the region are plains and is culturally similar to Ernakulam whereas the eastern parts are highlands and differ from the western parts as most of the region are agricultural areas. The regions of Thodupuzha and Kothamangalam were called sub-high range or Keezhmalanad of erstwhile Vadakkumkoor Kingdom indicating these as lands with fertile soils deposited by Thodupuzha and Muvattupuzha rivers over a period of time due to floodings of the banks.
While and nearby areas are less hilly and fertile. The altitude is much lesser and the hilly region is the Kadalikkad-Meenkunnam-Pamp
Korapuzha known as Elathur River, is a short river of 40 km, with a drainage area of 624 km2, flowing through the Kozhikode district of Kerala state in India. It is formed by the confluence of two streams and Punoor puzha which originate in the mountains of Wayanad district; the Korapuzha empties into the Arabian Sea at Elathur. The river and its main tributaries become tidal as they near the Arabian Sea. There is heavy boat traffic over the last 25 km of its course, it forms part of the West Coast Inland Navigation System. This 480-metre bridge is the longest bridge in Kozhikode district. Completed in 1940, it has 13 spans; the surroundings are lush green and photogenic. The Korapuzha is considered as the cordon sanitaire between the North Malabar and South Malabar in the erstwhile Malabar District; until the 20th century the Nair women of North Malabar crossing the Korapuzha and going south or marrying a person from South Malabar was considered a taboo and those who violated faced Bhrasht and forfeiture of caste.
Some difference can be seen in Thiyya community as well. Land south of Korapuzha is considered North of Korapuzha is Kolathunadu. "Infobox facts". All Kerala River Protection Council. Retrieved 26 January 2006. Malabar Manual in two volumes by William Logan, first published in 1887, reprinted by Asian Educational Services in 1951. Nayars of Malabar Vol III by F. Fawcett, first published in 1901