295
observed in Golaghat District (113) followed
by Dhubri (73) and Nagaon (68) districts.
However, the highest area of wetlands is in
Kamrup District (15,705.00 ha) followed by
Nagaon (2,175.50 ha) and Dhubri (1,816.50 ha)
districts. Some of the important Beels are Sone
Beel in Karimganj District, Deepor Beel in
Kamrup District, Dhir Beel in Dhubri District,
Tamaranga Beel and Dalani Beel in Bongaigaon
District, etc.
20.2.3.2 Haor
These are discernible in satellite imagery by their
reddish tone indicating the presence of vegetation, associated with dark blue tone indicating the
presence of water. In Assam, out of 1,392 wetlands, there are approx. 610 Haors covering an
area of 43,433.50 ha constituting 0.55 % of the
total geographical area of the State and 42.91 %
of the total area under wetlands. Their size ranges
from 2.5 ha (smallest) to 1,350.0 ha (largest).
20.2.3.3 Anua
Out of the total of 1,392 wetlands in Assam, there
are 290 oxbow wetlands covering an area of
5,460.60 ha which constitutes approx.0.10 % of
the total geographical area of the state and 9.27 %
of the total area under wetlands. The smallest of
them measures 5.0 ha, while the largest measures
582.50 ha. The highest number of oxbow wetlands
is observed in Golaghat District (104) followed
by Nagaon District (71) and Dhubri District (68).
Maximum area of oxbow wetlands is in Morigaon
District (2,143.00 ha) followed by Nagaon
(1,746.00 ha) and Golaghat (1,563.00 ha) districts. Some of the important wetlands under this
category are Morikolong and Patoli beels in
Nagaon District, Mer Beel in Golaghat District,
Guruajan in Morigaon District, the Anuas in
Cachar District, etc.
20.2.3.4 Reservoirs
In Assam, there are about ten reservoirs covering
an area of 2,662.5 ha which constitutes 0.03 % of
the total geographical area of the state and 2.63 %
of the total area under wetlands. Their size ranges
from 17.50 ha (smallest) to 930.0 ha (largest).
20.2.3.5 Tanks
There are a large number of family-owned small
tanks in Assam. These are generally not reckoned
in remote sensing. In Assam, c 115 tanks have
been identifi ed from satellite data covering an
area of 749.00 ha which constitutes 0.01 % of the
total geographical area of the province and
0.74 % of the total area under wetlands. Their
size varies from 2.5 to 55 ha. Most of this type of
wetlands have low turbidity. The highest number
of tanks are observed in Sibsagar District (20)
followed by Kamrup (18) and Sonitpur (16). The
highest area of tanks is in Sibsagar District
(267.00 ha) followed by Sonitpur (83.50 ha) and
Kamrup (80.00 ha) districts. Some of the important wetlands under this category are Gaurisagar
Pukhuri, Sibsagar Pukhuri and Joysagar Pukhuri
in Sibsagar District. Besides providing water to
the people of the nearby areas, these tanks can
also be used for rearing fi shes; for raising plantation crops like coconut, areca nut and cashew nut
along the banks of the ponds; habitat for wetland
birds; and so on.
20.2.3.6 Physico-chemical Features
Some of the salient physico-chemical characteristics
of water of the Beels are given below:
Temperature 9.2 to 39°, water level 0.25–9.0 m,
pH 6–7.8, DO 4.5–7.2 mg/l and TA 52.2–105.5 mg/l.
20.2.3.7 Biodiversity
There is, generally, abundant plankton in the
Beels of Assam. Some of the abundant genera
are Microcystis, Anabaena, Spirogyra, Volvox,
Ankistrodesmus, Closterium, Chlorella, Euglena,
Ceratium, Cosmarium, Pinnularia, Navicula,
Gyrosigma, Diatoma, Brachionus, Keratella,
Trichocerca,
Filinia,
Lecane,
Daphnia,
Ceriodaphnia, Simocephalus, Scapholeberis,
Moina, Bosmina, Bosminopsis, Chydorus, Alona,
Pleuroxus, Camptocercus, Dadaya, Cyclops,
Diaptomus, etc.
Similarly, aquatic macrophytes (AM) are also
abundant in many wetlands of Assam. Some of
the abundant genera are Hydrilla, Vallisneria,
Nechamandra, Lemna, Pistia, Eichhornia, Trapa,
Nymphaea, Nymphoides, Nelumbo, Justicia,
20.2 Wetlands of Northeast India (The Water Wealth of Northeast India)
observed in Golaghat District (113) followed
by Dhubri (73) and Nagaon (68) districts.
However, the highest area of wetlands is in
Kamrup District (15,705.00 ha) followed by
Nagaon (2,175.50 ha) and Dhubri (1,816.50 ha)
districts. Some of the important Beels are Sone
Beel in Karimganj District, Deepor Beel in
Kamrup District, Dhir Beel in Dhubri District,
Tamaranga Beel and Dalani Beel in Bongaigaon
District, etc.
20.2.3.2 Haor
These are discernible in satellite imagery by their
reddish tone indicating the presence of vegetation, associated with dark blue tone indicating the
presence of water. In Assam, out of 1,392 wetlands, there are approx. 610 Haors covering an
area of 43,433.50 ha constituting 0.55 % of the
total geographical area of the State and 42.91 %
of the total area under wetlands. Their size ranges
from 2.5 ha (smallest) to 1,350.0 ha (largest).
20.2.3.3 Anua
Out of the total of 1,392 wetlands in Assam, there
are 290 oxbow wetlands covering an area of
5,460.60 ha which constitutes approx.0.10 % of
the total geographical area of the state and 9.27 %
of the total area under wetlands. The smallest of
them measures 5.0 ha, while the largest measures
582.50 ha. The highest number of oxbow wetlands
is observed in Golaghat District (104) followed
by Nagaon District (71) and Dhubri District (68).
Maximum area of oxbow wetlands is in Morigaon
District (2,143.00 ha) followed by Nagaon
(1,746.00 ha) and Golaghat (1,563.00 ha) districts. Some of the important wetlands under this
category are Morikolong and Patoli beels in
Nagaon District, Mer Beel in Golaghat District,
Guruajan in Morigaon District, the Anuas in
Cachar District, etc.
20.2.3.4 Reservoirs
In Assam, there are about ten reservoirs covering
an area of 2,662.5 ha which constitutes 0.03 % of
the total geographical area of the state and 2.63 %
of the total area under wetlands. Their size ranges
from 17.50 ha (smallest) to 930.0 ha (largest).
20.2.3.5 Tanks
There are a large number of family-owned small
tanks in Assam. These are generally not reckoned
in remote sensing. In Assam, c 115 tanks have
been identifi ed from satellite data covering an
area of 749.00 ha which constitutes 0.01 % of the
total geographical area of the province and
0.74 % of the total area under wetlands. Their
size varies from 2.5 to 55 ha. Most of this type of
wetlands have low turbidity. The highest number
of tanks are observed in Sibsagar District (20)
followed by Kamrup (18) and Sonitpur (16). The
highest area of tanks is in Sibsagar District
(267.00 ha) followed by Sonitpur (83.50 ha) and
Kamrup (80.00 ha) districts. Some of the important wetlands under this category are Gaurisagar
Pukhuri, Sibsagar Pukhuri and Joysagar Pukhuri
in Sibsagar District. Besides providing water to
the people of the nearby areas, these tanks can
also be used for rearing fi shes; for raising plantation crops like coconut, areca nut and cashew nut
along the banks of the ponds; habitat for wetland
birds; and so on.
20.2.3.6 Physico-chemical Features
Some of the salient physico-chemical characteristics
of water of the Beels are given below:
Temperature 9.2 to 39°, water level 0.25–9.0 m,
pH 6–7.8, DO 4.5–7.2 mg/l and TA 52.2–105.5 mg/l.
20.2.3.7 Biodiversity
There is, generally, abundant plankton in the
Beels of Assam. Some of the abundant genera
are Microcystis, Anabaena, Spirogyra, Volvox,
Ankistrodesmus, Closterium, Chlorella, Euglena,
Ceratium, Cosmarium, Pinnularia, Navicula,
Gyrosigma, Diatoma, Brachionus, Keratella,
Trichocerca,
Filinia,
Lecane,
Daphnia,
Ceriodaphnia, Simocephalus, Scapholeberis,
Moina, Bosmina, Bosminopsis, Chydorus, Alona,
Pleuroxus, Camptocercus, Dadaya, Cyclops,
Diaptomus, etc.
Similarly, aquatic macrophytes (AM) are also
abundant in many wetlands of Assam. Some of
the abundant genera are Hydrilla, Vallisneria,
Nechamandra, Lemna, Pistia, Eichhornia, Trapa,
Nymphaea, Nymphoides, Nelumbo, Justicia,
20.2 Wetlands of Northeast India (The Water Wealth of Northeast India)