449
thick layer of recent alluvium brought down by
the Irrawaddy. Three main types of soil have
developed, namely, meadow gleyey clay soils,
meadow swampy soils and saline gleyey soils.
The fl ow in the Irrawaddy is at its lowest in
February and March and maximum in July or
August. The only major canal is the Twante
Canal which links Rangoon with the western part
of the delta.
The Irrawaddy Delta comprises the main arms
of Pathein River, Pyapon River, Bogale River and
Toe River. Mawtin Point, formerly Cape Negrais,
is a famous landmark in the Irrawaddy Division,
and it also marks the southwest end of Myanmar.
The highest point of the Delta, Waphu Mount
(404 m MSL), lies between Pathein and Mawtin
Zun (point), on the western strip of the delta. A
major portion of the area is covered with lowlying lands at just 3 m MSL.
The waters of these rivers are very turbid due
to a heavy silt load they carry, and the sea is very
shallow with depths less than 5.5 m across the
coastline and in the east for a distance of up to
28 km offshore. As a result of constant accretion
into the sea, the delta is advancing at a rate of
5–6 km per 100 years, equivalent to about
1,000 ha per year.
The upper and central portions of the delta are
almost entirely under cultivation, principally for
rice. Until about 1850, much of this region comprised a complex of permanent and seasonal
lakes, swamps and marshes, and vast areas of
seasonally inundated plains and swamp forest.
However, following the rush of settlers from
Upper to Lower Burma in the late nineteenth century, the construction of embankments and reclamation of land for agriculture has not, possibly,
kept pace with the increase in population.
Islands
The principal islands are Haingyi Kyun, Leit
Kyun (Turtle Island), Pyin Salu Kyun and
Meinmahla Kyun (Pretty Women Island).
21.7.1.2 Climate
Annual rainfall in the delta region is approx.
1,500–2,000 mm in the north, 2,500 mm in the
southeast and 3,500 mm in the southwest. The
average air temperature is 32 °C. Most of the
rainfall occurs during the monsoons between
mid-May and mid-November. It is cool and dry
from mid-October to mid-February. During the
monsoon season, the maximum and minimum
temperatures in the coastal zone are about 37 °C
and 22 °C, respectively.
21.7.1.3 History
The delta was historically populated by the Mon.
However, politically, the Burman kingdom, situated further north of the Irrawaddy River, had
controlled the delta area since mid-eleventh century. The control of the fertile area reverted back
to Bago-based Mon kingdoms in the thirteenth to
fi fteenth centuries (1287–1539) and briefl y in
eighteenth century (1747–1757). Further, the
delta was, perhaps, the fi rst place where the colonial British had invaded for their rule. The British,
in turn, had drained the marshes and swamps and
had built dykes and embankments, since 1861,
for farming rice, etc. The Burmans had later
migrated here. There now exist 1,300 km of
major embankments in the delta to protect
600,000 ha of paddy land.
21.7.1.4 Inhabitants
It is mainly populated by farming and fi shing
communities in several villages besides market
towns, mostly located along the main rivers. At
100 per km
2 , it is one of the most densely populated regions in the country with a total population of 3.5 million. Current inhabitants include,
apart from the Mon and Bamar, a majority Pwo
Kayin and Muslims.
21.7.1.5 Economy and Development
It is one of the largest rice-producing regions of
the world. So, the roads of the region are quite
good and renovated during 1990s and 2000s.
Two-thirds of the total arable land is under rice
cultivation with a yield of about 2,000–2,500 kg/ha.
Fishing is carried out from fi xed fi shing frames
as well as from small boats. Prawn fi shery and
harvesting sea turtle eggs are also major commercial activities both of which are now threatened
21.7 Wetlands of Myanmar
thick layer of recent alluvium brought down by
the Irrawaddy. Three main types of soil have
developed, namely, meadow gleyey clay soils,
meadow swampy soils and saline gleyey soils.
The fl ow in the Irrawaddy is at its lowest in
February and March and maximum in July or
August. The only major canal is the Twante
Canal which links Rangoon with the western part
of the delta.
The Irrawaddy Delta comprises the main arms
of Pathein River, Pyapon River, Bogale River and
Toe River. Mawtin Point, formerly Cape Negrais,
is a famous landmark in the Irrawaddy Division,
and it also marks the southwest end of Myanmar.
The highest point of the Delta, Waphu Mount
(404 m MSL), lies between Pathein and Mawtin
Zun (point), on the western strip of the delta. A
major portion of the area is covered with lowlying lands at just 3 m MSL.
The waters of these rivers are very turbid due
to a heavy silt load they carry, and the sea is very
shallow with depths less than 5.5 m across the
coastline and in the east for a distance of up to
28 km offshore. As a result of constant accretion
into the sea, the delta is advancing at a rate of
5–6 km per 100 years, equivalent to about
1,000 ha per year.
The upper and central portions of the delta are
almost entirely under cultivation, principally for
rice. Until about 1850, much of this region comprised a complex of permanent and seasonal
lakes, swamps and marshes, and vast areas of
seasonally inundated plains and swamp forest.
However, following the rush of settlers from
Upper to Lower Burma in the late nineteenth century, the construction of embankments and reclamation of land for agriculture has not, possibly,
kept pace with the increase in population.
Islands
The principal islands are Haingyi Kyun, Leit
Kyun (Turtle Island), Pyin Salu Kyun and
Meinmahla Kyun (Pretty Women Island).
21.7.1.2 Climate
Annual rainfall in the delta region is approx.
1,500–2,000 mm in the north, 2,500 mm in the
southeast and 3,500 mm in the southwest. The
average air temperature is 32 °C. Most of the
rainfall occurs during the monsoons between
mid-May and mid-November. It is cool and dry
from mid-October to mid-February. During the
monsoon season, the maximum and minimum
temperatures in the coastal zone are about 37 °C
and 22 °C, respectively.
21.7.1.3 History
The delta was historically populated by the Mon.
However, politically, the Burman kingdom, situated further north of the Irrawaddy River, had
controlled the delta area since mid-eleventh century. The control of the fertile area reverted back
to Bago-based Mon kingdoms in the thirteenth to
fi fteenth centuries (1287–1539) and briefl y in
eighteenth century (1747–1757). Further, the
delta was, perhaps, the fi rst place where the colonial British had invaded for their rule. The British,
in turn, had drained the marshes and swamps and
had built dykes and embankments, since 1861,
for farming rice, etc. The Burmans had later
migrated here. There now exist 1,300 km of
major embankments in the delta to protect
600,000 ha of paddy land.
21.7.1.4 Inhabitants
It is mainly populated by farming and fi shing
communities in several villages besides market
towns, mostly located along the main rivers. At
100 per km
2 , it is one of the most densely populated regions in the country with a total population of 3.5 million. Current inhabitants include,
apart from the Mon and Bamar, a majority Pwo
Kayin and Muslims.
21.7.1.5 Economy and Development
It is one of the largest rice-producing regions of
the world. So, the roads of the region are quite
good and renovated during 1990s and 2000s.
Two-thirds of the total arable land is under rice
cultivation with a yield of about 2,000–2,500 kg/ha.
Fishing is carried out from fi xed fi shing frames
as well as from small boats. Prawn fi shery and
harvesting sea turtle eggs are also major commercial activities both of which are now threatened
21.7 Wetlands of Myanmar