Dal Lake

Dal is a freshwater lake in Srinagar, the summer capital of Jammu and Kashmir in Indian-administered Kashmir. It is an urban lake, the second largest lake in Jammu and Kashmir, and the most visited place in Srinagar by tourists and locals. It is integral to tourism and recreation in the Kashmir Valley and is variously known as the "Lake of Flowers", "Jewel in the crown of Kashmir" or "Srinagar's Jewel". The lake is also an important source for commercial operations in fishing and water plant harvesting.
The shore line of the lake, about, is encompassed by a boulevard lined with Mughal era gardens, parks, houseboats and hotels. Scenic views of the lake can be witnessed from the shore line Mughal gardens, such as Shalimar Bagh and Nishat Bagh built during the reign of Mughal Emperor Jahangir, and from houseboats cruising along the lake in the colourful shikaras. During the winter season, the temperature can sometimes reach as low as, freezing the lake.
The lake covers an area of and is part of a natural wetland which covers, including its floating gardens. The floating gardens, known as "Raad" in Kashmiri, blossom with lotus flowers during July and August. The wetland is divided by causeways into four basins; Gagribal, Lokut Dal, Bod Dal and Nigeen. Lokut Dal and Bod Dal each have an island in the centre, known as Rupa Lank and Sona Lank respectively.
At present, the Dal and the Mughal gardens on its periphery are undergoing intensive restoration measures to fully address the serious eutrophication problems experienced by the lake. Massive investments of approximately US$275 million are being made by the Government of India to restore the lake to its original splendour.

History

Dal is mentioned as Mahasarit in ancient Sanskrit texts. Ancient history records mention that a village named Isabar to the east of Dal was the residence of goddess Durga.
This place was known as Sureshwari on the bank of the lake, which was sourced by a spring called the Satadhara.
The name "Sureshwari" refers to the goddess Parvati, suggesting that the lake was once considered sacred and possibly associated with the goddess.
During the Mughal period, the Mughal rulers of India designated Kashmir, Srinagar in particular, as their summer resort. They developed the precincts of the Dal in Srinagar with sprawling Mughal-type gardens and pavilions as pleasure resorts to enjoy the salubrious cool climate. After the death of Aurangzeb in 1707, which led to the disintegration of the Mughal Empire, Pashtun tribes in the area around the lake and city increased, and the Afghan Durrani Empire ruled the city for several decades. In 1814 a significant part of the Kashmir valley, including Srinagar, was annexed from the Afghans by Maharaja Ranjit Singh to his kingdom, and the Sikhs grew in influence in the region for 27 years.
During the Dogra Raj, Srinagar became the capital of Dogra territory, attracted by the cool climate of the Kashmir valley, amidst the back drop of the majestic snow covered Himalayan ranges. The lake precincts experience temperatures in the range of during winter and during the summer season. The lake freezes when temperatures drop to about during severe winter. Although the Dogra Maharaja of Kashmir restricted the building of houses in the valley, the British circumvented this rule by commissioning lavish houseboats to be built on the Dal. The houseboats have been referred to as, "each one a little piece of England afloat on Dal."
After the independence of India, the Kashmiri Hanji people have built, owned and maintained these houseboats, cultivating floating gardens and producing commodities for the market, making them the centre of their livelihoods. The houseboats, closely associated with Dal also provide accommodation in Srinagar. Following the Mughal, Afghan, Sikh and Dogra rule, the place has earned the epithet, "Jewel in the crown of Kashmir".

Physical properties

Topography

The lake is located within a catchment area covering in the Zabarwan mountain valley, in the foothills of the Shankaracharya Hill, which surrounds it on three sides. The lake, which lies to the east and north of Srinagar city covers an area of, although including the floating gardens of lotus flowers, it is . The main basin draining the lake is a complex of five interconnected basins with causeways; the Nehru Park basin, the Nishat basin, the Hazratbal basin, the Nigeen basin and the Barari Nambal basin. Navigational channels provide the transportation links to all the five basins.
The average elevation of the lake is. The depth of water varies from at its deepest in Nigeen lake to, the shallowest at Gagribal. The depth ratio between the maximum and minimum depths varies with the season between 0.29 and 0.25, which is interpreted as flat bed slope. The length of the lake is with a width of. The lake has a basin having shore length of and roads run all along the periphery. Irreversible changes through urban developments have placed further restrictions on the flow of the lake and as a result, marshy lands have emerged on the peripheral zones, notably in the foothill areas of the Shankaracharya and Zaharbwan hills. These marshy lands have since been reclaimed and converted into large residential complexes.

Geology

Multiple theories explaining the origin of this lake have been formulated. One version is that it is the remnants of a post-glacial lake, which has undergone drastic changes in size over the years and the other theory is that it is of fluvial origin from an old flood spill channel or ox-bows of the Jhelum River. The dendritic drainage pattern of the catchment signifies that its rock strata have low levels of porosity. Lithologically, a variety of rock types have been discerned namely, igneous, metamorphic and sedimentary. The Dachigam Telbal Nallah system is conjectured to follow two major lineaments. Discontinuous surfaces seen in the terrain are attributed to the angular and parallel drainage pattern. The water table cuts the hill slopes, which is evidenced by the occurrence of numerous springs in the valley. Seismic activity in the valley is recorded under Zone V of the Seismic Zoning Map of India, the most severe zone where frequent damaging earthquakes of intensity IX could be expected. In the year 2005, Kashmir valley experienced one of the severe earthquakes measured at 7.6 on the Richter's scale, which resulted in deaths and the destruction of many properties, leaving many homeless.

Hydrology

The shallow, open-drainage lake is fed by Dachigam-Telbal Nallah, Dara Nallah and many other small streams. The lake is classified as 'warm monomictic' under the sub-tropical lake category. Spring sources also contribute to the flow, although no specific data is available to quantify their contribution.
To address this, water balance studies to analyse and assess the characteristics of flow have been conducted in order to approximate the discharge contributed by the springs in the lake bed. The complex land use pattern of the valley is reflected in the urbanised Srinagar in its north, with rice fields, orchards and gardens in the lower slopes, and barren hills beyond steep sloping hills. The flat topography also affects drainage conditions. It receives an average annual rainfall of in the catchment, but during the summer, snow melt from the higher ranges of the catchment results in large inflows into the lake.
The maximum flood discharge of Telbal Nallah has been assessed as 141.5 metres³/s for a one in hundred return period; the 1973 observed flood in Telbal Nallah has been estimated as 113 metres³/s. The average annual flow, according to discharge measurements, has been estimated as 291.9 million cubic metres, with Telbal Nalah accounting for 80% of the total and 20% contributed by other sources. The silt load has been estimated at 80,000 tonnes per year with 70% contribution from the Telabal Nallah, with 36,000 tonnes recorded as settling in the lake.
There are two outlets from the lake, namely the Dalgate and Amir Khan Nallah that connects the lakes of Nigeen and Anchar Lake. Dalgate is controlled by a weir and lock system. The outflow from these two outlets has been estimated as 275.6 million cubic metres.

Flora and fauna

The ecosystem of Dal is ecologically rich in macrophytes, submerged macrophytes, floating macrophytes and phytoplankton. Macrophyte flora recorded in the lake's aquatic and marshland environment consists of 117 species, belonging to 69 genera and 42 families. The lake is noted in particular for its Nelumbo nucifera which bloom in July and August. The prolific growth of Ceratophyllum demersum in the eutrophic zones has been reported, with Myriophyllum spicatum and Potemogetton lucens cited as dominant species. Other macrophytes discerned in different zones of the lake include Typho angustata, Phragmites australis, Myriophyllum, Sparganium evectum and Myriophyllum verticillatum, which contribute to the production of macrophytes. The rooted variety of the floating leaf type consists of Nelumbo nucifera, N. alba, N. tetragonia, N. candida, Nymphoides peltata, Salvinia natans, Hydrocharis dubia, and Potamogeton natans, all of which occupy 29.2% of the lake. Phytoplanktons include Navicula radiosa, Nitzschia accicularis, Fragilaria crotonensis, Diatoma elongatum, Scenedesmus bijuga, Pediastrum duplex, Tetraedron minimum, Microcystis aeruginosa and Merismopedia elegans.
Since 1934, some important changes have been observed in the lake's biota, including a reduction in the number of Chara species, and an increase in the area covered by Salvinia since 1937. Analysis of the lake has also revealed the tendency for it to develop monospecific communities of submerged macrophytes such as Ceratophyllum and Myriophyllum.
Woody vegetation in the catchment of the lake consists of species of Melia, Ailanthus, Robinia, Daphne, Celtis, Roses, Ephedra, and Pinus roxburghii, Pinus halepensis, Pinus gerardiana, Cupressus torulosa and Cupressus arizonica. The valley also has a rich cultivation of crops such as paddy, wheat and fodder.
Floating gardens, labelled the 'Rad' in the Kashmiri language are a special feature of the lake. They basically constitute of matted vegetation and earth, but are floating. These are detached from the bottom of the lake and drawn to a suitable place and anchored. Given its rich nutrient properties, tomatoes, cucumbers and melons are grown with noteworthy results.
Faune found in the lake include Keratella cochlearis, K. serrulata, Polyactis vulgaris, Brachionus plicatilis, Monostyla bulla, Alona monocantha, Cyclops ladakanus and Mesocyclops leukarti, all zooplankton, Chironomus species, and Tubifex species, and fish including Cyprinus carpio specularis, C. carpio communis, Schizothorax niger, S. esocinus, S. curviformis and Crossochelius latius. It is also reported that Cyprinus, introduced in the early sixties, are dominant and that the indigenous species Schizothorax niger is showing a declining trend.
;Fishing resources
The fishing industry on Dal is the second largest industry in the region and is central to many of the people's livelihoods who reside on the lake's periphery. Dal's commercial fisheries are particularly reliant on carp fish species, which were introduced into the lake in 1957. As a result, carp constitutes 70% of all the fish caught in the lake while the schizothorax constitutes 20% and other species account for 10%. Fishermen use a locally manufactured cast net which comprises six parts with a diameter of 6 metres. It is operated from a wooden fishing boat made out of deodar, typically 20ftx4ft in size. The gradual decline in quality of the lake water through pollution has resulted in lower fish stocks and the extinction of endemic varieties of fish. The causes for such deterioration have been identified and remedial actions have been initiated. The various fishing nets being used in Dal are cast net, Long line, Gill net, Rod and line, Scoop net .
The lake is warm monomictic and the pH value recorded has varied from a minimum of 7.2 to a maximum of 8.8 on the surface over a yearly period. The Dissolved oxygen value has varied from a minimum of 1.4 to a maximum of 12.3 on the surface within a year. The Recorded maximum nitrogen concentration of phosphorus, and 241.18 tonnes of inorganic nitrogen into the lake from a discharge of 11.701 million cubic metres /year. Non-point sources, such as seepage and diffused runoff, also add to this pollution and have been recorded as further adding 4.5 tonnes of total phosphates and 18.14 tonnes of nitrogen to the lake. Based on the values mentioned above, it has been inferred that the water quality of the lake has deteriorated.
The major environmental problem facing the lake is eutrophication, which has required immediate remedial measures to combat it. Alarmingly, the size of the lake has shrunk from its original area of to the present area of, and there is a concerning rate of sediment deposition due to catchment area degradation.
The water quality has also deteriorated due to intense pollution caused by the untreated sewage and solid waste that is fed into the lake from the peripheral areas and from the settlements and houseboats. Besides, some experts like Dr. A.A. Kazmi believe that deforestation in the catchment of Dal and Telbal stream may have led to more nitrogen and phosphorus-rich run-off, further aiding eutrophication. Encroachments of water channels and consequent clogging has diminished the circulation and inflows into the lake, so with the building up of phosphates and nitrogen, this has led to extensive weed growth and consequences on the biodiversity of the lake.