298
originated after the Dupitila sedimentation
during the Mio-Pliocene period.
Around Sone Beel, the soil in the catchment of
the plains is generally loamy, but occasionally
sandy or gravelly admixed with quartz. Conversely,
hilly portion of the catchment generally consists of
fi ne grain sandstones bearing many angiosperms
and thus forming the evergreen forest.
The principal feeder of Sone Beel is the major
infl ow, the River Singla which drains a total
catchment area of c 46,105 ha. The wetland also
receives water from 12 minor inlets and many
other canals fl owing from both hills and plains,
all of which together drain a total of c 18,941.9 ha
of the catchment area of the wetland. Out of this,
c 11,003.9 ha lies in the plains, while c 7,938.0 ha
falls in the hilly portion of the wetland. These,
otherwise, form, respectively, 58.09 and 41.91 %
of the total catchment area of the wetland.
Further, the catchment of the wetland also
includes the reserve forests (RF) of the State,
notably the Singla RF. During monsoon, the wetland receives some humic as well as inorganic and
organic nutrients from the hillocks and cultivable
areas, particularly around the swollen tail end of
the wetland.
On the west, the wetland is connected to
Karimganj town by a c 30.0-km railway line,
whereas Badarpur Junction is situated at a distance of c 24.5 km from the north of the wetland.
The nearest town Hailakandi is situated at a distance of c 9.5 km to its east. The Block HQ
Ramkrishna Nagar is situated at a distance of c
8.5 km from the south end of the wetland.
The maximum length ( L ) and breadth ( B ) of
the wetland at full storage level (FSL) were measured as 12.5 km and 3.9 km, respectively.
Interestingly, these values were found to shrink
(reduce) to 4.07 km and 2.22 km, respectively, at
its dead storage level (DSL).
The area of Sone Beel at FSL was measured as
3,458.12 ha, while, at DSL, the area diminished
to only 409.37 ha. The length of the shoreline
was measured as 35.4 km, while the shore and
volume developments were recorded as 1.69 and
0.15, respectively, with mean depth of 0.29 m.
The gross volume of the wetland was found to be
101.54 × 10
6 m
3 .
Silt Islands (SI) were recorded on the northern
and southern parts of the wetland. Of these, the
Gopikanagar SI (area 3.74 ha and 25 MSL) and
Khagdi tila SI (area 3.31 ha and 21 MSL) were
noteworthy. Interestingly, the wetland surface
itself is situated 23 m above the sea level (MSL).
The wetland basin tended to become deeper
from south to north. The contours in the west
were found to be almost parallel and closer than
their counterparts in the east.
Although the wetland did exhibit variable water
level ranging from 0.07 to 5.69 m at FSL (June–
September) and 0.02–2.08 m at DSL (November–
April), the average depth of the wetland was found
to vary from 0.18 m (February 2007) to 3.34 m
(September 2007) in 2007 and 0.16 m (January
2008) to 3.38 m (June 2008) during 2008.
Twelve minor inlets occur in different parts of
the wetland. But the wetland is mainly fed with the
major inlet, the River Singla. It originates as
‘Thing Tlawng Lui’ at a height of c 365.21 m MSL
in Mizo Hills, from where, after traversing a meander
course of c 62.75 km, it enters Sone Beel.
The major outfl ow (there being no minor
outfl ow) of the wetland, the River Kachua, lies at
northern most end of the wetland. It drains out
the wetland water into the mighty River Kushiara
after covering a length of c 19.30 km.
Although the River Kachua was blocked by a
blind dam constructed by the Government of
Assam in 1950–1951, the dam was replaced by a
lock gate in 1964 after experiencing navigational
and fi shery problems. The maximum outfl ow of
the wetland was found to be 87.03 m
3 /s in August
2008, while the maximum infl ow was recorded to
be 33.91 m
3
/s in July 2008. Concomitantly, the
minimum infl ow and outfl ow of the wetland were
recorded as 0.0027 m
3
/s and 0.087 m
3
/s (both in
February 2008).
The wetland, as a norm, was found to exhibit
a decreasing trend of its storage capacity from
post-monsoon period culminating in winter to
early summer whence it again gained its storage
at the onset of monsoon (Fig. 20.1c).
20 Wetlands of India
originated after the Dupitila sedimentation
during the Mio-Pliocene period.
Around Sone Beel, the soil in the catchment of
the plains is generally loamy, but occasionally
sandy or gravelly admixed with quartz. Conversely,
hilly portion of the catchment generally consists of
fi ne grain sandstones bearing many angiosperms
and thus forming the evergreen forest.
The principal feeder of Sone Beel is the major
infl ow, the River Singla which drains a total
catchment area of c 46,105 ha. The wetland also
receives water from 12 minor inlets and many
other canals fl owing from both hills and plains,
all of which together drain a total of c 18,941.9 ha
of the catchment area of the wetland. Out of this,
c 11,003.9 ha lies in the plains, while c 7,938.0 ha
falls in the hilly portion of the wetland. These,
otherwise, form, respectively, 58.09 and 41.91 %
of the total catchment area of the wetland.
Further, the catchment of the wetland also
includes the reserve forests (RF) of the State,
notably the Singla RF. During monsoon, the wetland receives some humic as well as inorganic and
organic nutrients from the hillocks and cultivable
areas, particularly around the swollen tail end of
the wetland.
On the west, the wetland is connected to
Karimganj town by a c 30.0-km railway line,
whereas Badarpur Junction is situated at a distance of c 24.5 km from the north of the wetland.
The nearest town Hailakandi is situated at a distance of c 9.5 km to its east. The Block HQ
Ramkrishna Nagar is situated at a distance of c
8.5 km from the south end of the wetland.
The maximum length ( L ) and breadth ( B ) of
the wetland at full storage level (FSL) were measured as 12.5 km and 3.9 km, respectively.
Interestingly, these values were found to shrink
(reduce) to 4.07 km and 2.22 km, respectively, at
its dead storage level (DSL).
The area of Sone Beel at FSL was measured as
3,458.12 ha, while, at DSL, the area diminished
to only 409.37 ha. The length of the shoreline
was measured as 35.4 km, while the shore and
volume developments were recorded as 1.69 and
0.15, respectively, with mean depth of 0.29 m.
The gross volume of the wetland was found to be
101.54 × 10
6 m
3 .
Silt Islands (SI) were recorded on the northern
and southern parts of the wetland. Of these, the
Gopikanagar SI (area 3.74 ha and 25 MSL) and
Khagdi tila SI (area 3.31 ha and 21 MSL) were
noteworthy. Interestingly, the wetland surface
itself is situated 23 m above the sea level (MSL).
The wetland basin tended to become deeper
from south to north. The contours in the west
were found to be almost parallel and closer than
their counterparts in the east.
Although the wetland did exhibit variable water
level ranging from 0.07 to 5.69 m at FSL (June–
September) and 0.02–2.08 m at DSL (November–
April), the average depth of the wetland was found
to vary from 0.18 m (February 2007) to 3.34 m
(September 2007) in 2007 and 0.16 m (January
2008) to 3.38 m (June 2008) during 2008.
Twelve minor inlets occur in different parts of
the wetland. But the wetland is mainly fed with the
major inlet, the River Singla. It originates as
‘Thing Tlawng Lui’ at a height of c 365.21 m MSL
in Mizo Hills, from where, after traversing a meander
course of c 62.75 km, it enters Sone Beel.
The major outfl ow (there being no minor
outfl ow) of the wetland, the River Kachua, lies at
northern most end of the wetland. It drains out
the wetland water into the mighty River Kushiara
after covering a length of c 19.30 km.
Although the River Kachua was blocked by a
blind dam constructed by the Government of
Assam in 1950–1951, the dam was replaced by a
lock gate in 1964 after experiencing navigational
and fi shery problems. The maximum outfl ow of
the wetland was found to be 87.03 m
3 /s in August
2008, while the maximum infl ow was recorded to
be 33.91 m
3
/s in July 2008. Concomitantly, the
minimum infl ow and outfl ow of the wetland were
recorded as 0.0027 m
3
/s and 0.087 m
3
/s (both in
February 2008).
The wetland, as a norm, was found to exhibit
a decreasing trend of its storage capacity from
post-monsoon period culminating in winter to
early summer whence it again gained its storage
at the onset of monsoon (Fig. 20.1c).
20 Wetlands of India