Chilika Lake
Chilika Lake is the largest brackish water lagoon with estuarine character that sprawls along the east coast of Indian sub-continent in Asia and second largest coastal lagoon in the world, covering an area of over. It is spread over the Puri, Khordha and Ganjam districts of Odisha state on the east coast of India, at the mouth of the Daya River, flowing into the Bay of Bengal.
It has been listed as a tentative UNESCO World Heritage site. Its salinity varies by region, from freshwater where rivers flow in, to oceanic salinity levels due to tidal influx.
File:DSC_0764f.jpg|thumb|left|200px|Irrawaddy dolphin in Chilika Lake, Satpada
History
Geological evidence indicates that Chilika Lake was part of the Bay of Bengal during the later stages of the Pleistocene period.Excavations were conducted by the Archaeological Survey of India at Golabai Sasan, north of Chilika lake in Khurdha district. Golabai provides evidence of a sequence of Chilika area culture in three phases: Neolithic, Chalcolithic and Iron Age. Radiocarbon dating traced the earliest level of Golbai to 2300 BCE. The site is located on the left bank of the Malaguni River, a tributary of the Daya River, which flows into Chilika Lake. This location, which gave access to the sea via Chilika Lake, gives evidence of the maritime activities of this region. The recovery of many woodworking adzes and other artifacts shows that Golabai was a boat-building centre. Golabai is the only excavated site in Odisha where boat building has been revealed. This also indicates that Chilika lake was close to Golabai and it facilitated the maritime trade of people in the area during the ancient period.
Ancient texts say the southern sector of Chilika was a major harbour for maritime commerce, when Kharavela, the King of Kalinga, was known as the "Lord of the Sea".
Ptolemy, the Greek geographer, referred to Palur as the port Paloura, located close to the point of departure situated outside of the southern tip of the lake at Kantiagarh, from where ships bound for different parts of Southeast Asia, sailed. After 639, the Chinese pilgrims Fa-Hien and Hiuen-Tsang mention a famous port "Che-li-ta-loChing" near the shore of the ocean which was a thoroughfare and resting place for seagoing traders and strangers from distant lands. This port was located at 'Chhatragarh' on the banks of Chilika Lake.
A fourth-century legend, often told to explain the birth of Chilika, states that the pirate king, Raktabahu, planned to attack Puri with a huge fleet of ships. To avoid detection, he stealthily anchored out of sight, off the mouth to the sea. The deception was revealed by the ships' refuse floating to the shore, thus warning the town's people, who escaped with all their possessions. Raktabahu felt betrayed when he found an abandoned town and directed his fury towards the sea
that had betrayed him. The sea parted to let the army march in, then surged back, drowned the army and formed the present lake.
Archeological excavations discovered seventh-century ship anchors and stone memoirs dedicated to battle heroes at a village named Kanas, about north of Chilika on the banks of Nuna river, which flows into the lake. This gives evidence of a historic naval engagement off the coast.
A 10th-century text, the Brahmanda Purana, mentions Chilika Lake as an important centre of trade and commerce, and a shelter for ships sailing to Java, Malaya, Singhala, China and other countries. This suggests that the lake was then deep enough for berthing seagoing ships and had a channel to the sea big enough for loaded trading ships embarking to Southeast Asia. The villagers around Chilika Lake still observe an annual festival called "Bali Yatra".
In 1803, the British entered the shores of the lake, reached Puri and occupied Odisha with the help of Fateh Muhammed. Fateh Muhammed, in turn, was rewarded by the British with freehold of the areas of Malud and Parikud, of the present day Garh Krishnaprasad revenue block.
Over the years, poets including Kabibar Radhanath Ray and Pandit Godavarish Mishra, freedom fighters and Saints have extolled historicity of the lake as pertinent to its cultural, spiritual, religious and scenic aspects.
Chilika is an integral part of the culture of coastal Odisha. Almost 400 years ago, the saint poet Purshottam Das, a devotee of Lord Jagannath, wrote a poem about Lord Krishna dancing with a milkmaid called Maniki, who had come to sell curds on the banks of the Chilika.
"Gopabandhu Das, a famous Odiya poet, became impatient to see the beauty of the march of colorful sights and sounds of Chilika lagoon while going by train. He asked the speeding train to stop for a moment so that he could enjoy the beauty. It is because of the beauty that arrests him much".
Geology
The lake is of estuarine character in an ephemeral environment. Geological studies indicate that the coastline extended along the western shores of the lake in the Pleistocene era with its northeastern region lying under the sea. That the coastline has moved eastward over the ages is supported by the fact that the nearby Konark Sun Temple, built originally on the seashore a few hundred years ago, is now about, away from the coast.The catchment area of Chilika lake has a rock, sand and mud substratum. It contains a wide range of sedimentary particles such as clay, silt, sand, gravel and shell banks but the major part of the catchment area is silt. Around 1.6 million metric tons per year of sediment is deposited in Chilika lake by rivers Daya and several streams.
It is conjectured that a rise in worldwide sea levels over the last 6,000–8,000 years occurred with a pause in the rise of sea level about 7,000 years ago, which could have resulted in the formation of a sandy beach near the coast at the Southern sector. With the rise in the sea level, the sand beach grew gradually, progressed seaward to the northeast and formed the spit of Chilika. A fossil unearthed from the southwestern edge of the spit indicates that the lake was formed about 3,500–4,000 years ago. The abrupt change in the direction of the coast north of the lake, strong winds shifting sand to the shore, longshore drift, the presence or absence of strong river and tidal currents in different areas are the reasons attributed for the growth of the spit.
White bands of coral in the southern sector, at a height of, above the present water level, shows that the area was once marine and that the water was much deeper than present. The chronological development of the outer barrier spit of the lake has been dated by Optically stimulated luminescence studies of minerals. This was done on sixteen samples of the lake bed. The studies indicated doses of between 153 ± 3 mGy and 2.23 ± 0.07 Gy, corresponding to ages from 40 years at the top of the spit to 300 years at the bottom. The youngest ages are consistent with the age of the overlying vegetation. A clearly defined period of > of barrier construction 40 years ago is identified. Prior to that the deposition rate was relatively constant for 300 years.'"
Geography and topography
Chilika Lake is a shallow bar-built estuary with large areas of mudflats. The western and southern margins of the lake are fringed by the Eastern Ghats hill range.Several inland rivers, which bring silt into the lake, control the northern end of the lake. A long barrier beach called Rejhansa, formed by northerly currents in the Bay of Bengal, resulted in the formation of this shallow lake and forms its eastern side. As an ephemeral lake, its water surface area varies from in the summer monsoon season to in the winter dry season.
The water spread area of the lagoon ranges between during the monsoon and summer respectively. A long, narrow, outer channel connects the lagoon to the Bay of Bengal, near the village Motto. More recently, a new mouth has been opened by Chilika Development Authority which has brought a new lease of life to the lagoon.
The lake has numerous islands. The larger islands, separated by shallow channels, lie between the barrier and the main body of the lake. A total of channels connect the lake with Bay of Bengal. The six major islands are Parikud, Phulbari, Berahpura, Nuapara, Nalbana, and Tampara. These islands, together with the Peninsula of Malud, constitute the Krishnaprasad Revenue Block of Puri District.
The north shore of the lake is part of Khordha District and the western shore is part of Ganjam District. Due to siltation, the width of the barrier has fluctuated and the mouth to the sea has periodically been closed. The location of the mouth has also frequently shifted, generally towards the northeast. The mouth, which was wide in 1780, was only forty years later. The local fishermen, to maintain their livelihood, had to cut open the mouth to gain access to the sea for fishing.
Water depth of the lake varies from in the dry season to in the rainy season. The width of the old channel to the sea, now reported to be about, is known as Magarmukha. The lake is divided into four separate zones namely, the southern, central, northern sectors and the outer channel area. A long outer channel connects the lake with the Bay of Bengal at Arakhuda village. The lake is pear-shaped and has a maximum length of with a mean width of.
Another lake in India called Vembanad Lake is the longest lake in India.
Hydrology
Three hydrological subsystems control the hydrology of the lake. The land-based system comprises distributaries of the Mahanadi River on the northern side, 52 river channels from the western side and the Bay of Bengal on the eastern side. Two of the three southern branches of the Mahanadi River that trifurcates at Cuttack, feed the lake. 61% of the total freshwater inflow into the lake is contributed by these two branches.The second drainage system which is non–perennial accounts for 39% of the inflow. The important rivers of this drainage system are the Kansari, Kusumi, Janjira, and Tarimi rivers. The annual total surface freshwater input to the lake is estimated to be including direct precipitation over the lake contributing
All the inland river systems disgorge an annual flow of about of freshwater which is estimated to carry 13 million metric tons of silt into the lake. On the northeast, a channel connects the lake to the Bay of Bengal.
A tropical monsoon climate prevails over the drainage basin area of the lake. The lake experiences South–west and North-east monsoons during June to September and November to December respectively with an average annual rainfall of, with 72 rainy days. The maximum temperature of and minimum temperature of have been recorded.