Chalan
Beel
Chalan Beel one of
the largest inland depressions of
marshy character and also one of the
richest wetland areas of Bangladesh.
It is the largest beel of the country
and comprises a series of depressions
interconnected by various channels
to form more or less one continuous
sheet of water in the rainy season
when it covers an area of about 368
sq km. The beel extends over four
adjacent districts, Rajshahi, Pabna,
Sirajganj and Natore. The major parts
of it cover an extensive area of Raiganj
upazila of Sirajganj district and
Chatmohar upazila of Pabna district.
It lies between Singra upazila (Natore
district) and the north bank of the
river Gumani.
The southeastern
extremity of the beel is at Astamanisha
in Pabna district, close to Nunnagar,
where the Gumani and the baral meet.
Its northern boundary in this district
may be marked by a line drawn from
the east of Singra to the Bhadai river,
which forms the boundary between Rajshahi,
Pabna and Bogra. The eastern boundary
may be represented by a line drawn
north-south in Pabna and running through
Tarash upazila east of the Bhadai.
The greatest breadth of the beel is
about 13 km from Tarash at the northeast
to Narayanpur, near the north bank
of the Gumani. Its greatest length
is about 24 km from Singra to Kachikata
on the Gumani.
The main constituent
beels of Chalan beel are, from west
to east: (1) Purba Maddhanagar, (2)
Piprul, (3) Dangapara, (4) Laror,
(5) Tajpur, (6) Niala, (7) Chalan,
(8) Majhagaon, (9) Briasho, (10) Chonmohan,
(11) Satail, (12) Khardaha, (13) Darikushi,
(14) Kajipara, (15) Gajna, (16) Bara,
(17) Sonapatila, (18) Ghugudaha, (19)
Kuralia, (20) Chiral, (21) Dikshi
and (22) Gurka. The big-size depressions
(ie beels) are mostly in Pabna district.
They are: Gajna, Bara, Sonapatila,
Ghugudaha, Chiral and Gurka. Gajna
beel comprises an area of 123 sq km,
and is located to the south of Dulai.
Bara beel covers an area of 31 sq
km. Sonapatila beel lies in the northern
part of Pabna and has an area of 35
sq km. Kuralia and Dikshi beels cover
areas of 18 and 15 sq km respectively;
both are in Chatmohar upazila. Chiral
and Gurka beels cover an area of 8
sq km each and Ghugudaha beel is 4
sq km in size.
Chalan beel was formed
when the old brahmaputra diverted
its water into the new channel of
the jamuna. Chalan beel was probably
a backswamp before it was greatly
expanded with the inclusion of abandoned
courses of the karatoya and the atrai
and became a vast lake. The formation
of the Chalan beel is historically
linked with the demise of the Atrai
and the Baral. The Atrai or the Gur
was the principal feeder channel of
Chalan beel, which used to drain the
districts of Dinajpur and northern
Rajshahi. The Baral worked as an outlet
of the beel and eventually found its
way into the Jamuna. It was about
1,088 sq km in area at the time it
was formed.
The southern edge of the beel is skirted
by the Gumani, which carries the water
of the beel into Bara beel, which
in turn carries the water into the
Jamuna. During the rainy season the
Gumani overflows its banks and pours
its water into the beel. When the
Jamuna is flooded, the water of the
Baral is held up until the Jamuna
falls again. During the dry season,
the greater part of the beel dries
up, leaving a water basin of about
25.9 to 31.08 sq km, which may be
called its 'core'. However, the core
is not covered with an uninterrupted
expanse of water. It remains a collection
of shallow sheets of water connected
with each other by very tortuous channels.
Round the core, there are two concentric
irregular shaped oval areas growing
rice of the long-stemmed variety,
usually known as floating rice. The
first 'ring', rather narrow towards
the southwest, is covered with 1.53
to 1.83m of water during the rainy
season. The west of Chalan beel may
be included in the 'outer ring', where
water in the rainy season is much
less than other parts of the beel.
Both the rings dry up entirely between
December and June.
Chalan beel is rapidly
silting up. During the last century
and a half, it has shrunk at least
19.32 km from the southern side due
to annual deposits of silt from the
ganges. Its other feeder rivers like
the Gur and the Baral are also major
contributory factors in reducing the
size of the beel.
A survey carried
out in 1909 by the Public Works Department
into drainage and silting up of the
beel found that the previous area
of about 1,088 sq km have been reduced
to about 368 sq km. The remaining
area had been reclaimed either for
cultivation or settlement. Even in
this reduced area, only 86 sq km was
found under water all the year round.
It was estimated that the feeder rivers
had brought 6.3 million cu m of silt
a year of which 1.5 million cu m were
washed away by different drainage
channels coming out of the beel.
The remaining 4.8
million cu m had been deposited annually.
If distributed uniformly over the
whole of 368 sq km, it would have
raised the level at the rate of 1.27
cm a year. Another inquiry was made
in 1910 to further ascertain the condition
of the beel during the dry season.
It too found that the area had been
further reduced. A third investigation
carried out in 1913, ascertained that
only 31 to 39 sq km remained under
water throughout the year. The banks
around the core area were under cultivation
and the beel proper had 2.75 to 5.49m
of water in April. In the 1950s, various
reclamation works reduced the beel
to about 25.9 sq km. In 1987, it appeared
completely dry except for some small
man-made ponds.
Land in Chalan beel
is being reclaimed and new villages
are springing up alongside. In the
dry season, all the smaller and larger
beels dry up except their deeper centre.
The outlying marginal lands are cultivated
with boro and HYV (High Yield Variety)
rice in the dry season. In the wet
season, the shallow peripheries are
cultivated for deep-water aman rice
and jute.
Source: Banglapedia, National Encyclopedia
of Bangladesh
Asiatic Society of Bangladesh
