<Nature and Our Future: The Mekong Basin and Japan>

1. Diversity and Natural Abundancein the Mekong Basin
1-1. The Mekong River’s Natural Environment
The Natural Environment in the Mekong Basin
The Mekong River is an international waterway that begins in the Tibetan Plateaus and flows
through the Mekong Delta into the South China Sea, and it is second only to the Amazon in aquatic
biodiversity (Peterson and Middleton 2010). Along with 850 species of fish, there are 20,000 speciesof plants, 430 animal species, 1,200 bird species, and 800 reptile and amphibian species that live there(Thompson 2008). The entire river basin is 795,000 km2 and has a length of 4,909 km (MRC 2000: 5).
Langca ng

CHINAR.

Yunnan Province
Simao

BURMA(Myanmer)

Hanoi

LAOS
ChiangKhong

Luang Pabang

Vientiane
hr amgk

Bangkok.

R.

ong R.

Mu

C hi

R

THAILAND

nn R.

K

e San R.

P ho ng R . So

Se(Yangon).
kong R
MeRangoon.

S
Ratanakiri
Siem Reap
S re PokR
Battambang
Tonle Sap Stung Treng
Lake
PursatKompong
Chhnang
VIETNAMCAMBODIA

Phnom Penh

Figure 1: Mekong River

The distance between the source of rivers and the deltas in Japan is relatively short, and incomparison, the Mekong flows a very long distance (Tone River Management Office of the Ministryof Land, Infrastructure, Transport, and Tourism, Kanto Regional Development Bureau). One of theMekong’s unique characteristics is that in spite of its length, there is not much difference in altitude
between the upstream (not including the river’s source) and the delta.
The Mekong River passes through the 6 countries of China (Qinghai and Yunnan Provinces), Burma/
Myanmar1, Laos, Thailand, Cambodia, and Vietnam, and then flows into the sea. In upstream China,the headstreams of three of the world’s great rivers, the Yangtze, Mekong, and Salween flow in close
proximity, and this geography is known as the “Three Parallel Rivers.” The Mekong River then enters
Laos, flows along the border of Burma and Laos, and then after flowing along the Thai-Lao border,
enters Cambodia where it connects with the Tonle Sap Lake, a symbol of Cambodia. It then enters
Vietnam, where it is known as “Nine Dragons River.” The Mekong Delta in Vietnam is one of theworld’s largest rice production areas, and from there, the Mekong flows into the South China Sea.
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<Nature and Our Future: The Mekong Basin and Japan>

The Mekong originates with melting snow from the Himalayas. Water from the river’s catchment area
in China makes 16% of the river’s flow, and Burma 2%, Laos 35%, Thailand 18%, Cambodia 18%,
and Vietnam 11% (MRC 2005).
Catchment area(km2)
Catchment (% ofentire watershed)
Volume (% ofentire watershed)

ChinaBurma

Lao PDR

ThailandCambodia

Vietnam

Entire Region

165,000

24,000202,000

184,000

155,000

65,000795,000

2132523208100

16235181811100

Table: Comparison of 6 Countries in the Mekong River’s Catchment Area (MRC 2005:1).

The Mekong River Basin has a tropical monsoon
climate. From mid-May to October, the southwest
monsoon brings the rainy season. From November
to mid-March, the region is affected by the northeast
monsoon to bring the dry season (MRC 2010: 14).
The dry season continues until April, and then again in
May the rains fall signalling the beginning of the wet
season. Aside from the area in China, the hottest timeof year is around April.
Annual rainfall in northeast Thailand’s Ubon
Ratchathani Province is 1,500 mm. This isapproximately the same as Tokyo, but as one canFigure 2: Temperature and Rainfall in Ubon Ratchathani
Prefecture (Thai Meteorological Department of Ubon see from Figure 2, rainfall is concentrated between
Ratchathani 2004)
May and September. From October, there is almost
no rainfall until May the following year when thewet season begins. The Mun River, which flows through Ubon Ratchathani, is influenced by this rain
pattern, so water levels rise in May to peak in October. Then from November to April, the water levels
again gradually decrease.
References
Mekong River Commission (MRC). 2005. Overview of the Hydrology of the Mekong Basin.
http://www.mekonginfo.org/assets/midocs/0001968-inland-waters-overview-of-the-hydrology-of-the-mekong-basin.pdf
Mekong River Commission (MRC). 2010. State of the Basin Report 2010.
http://www.mrcmekong.org/assets/Publications/basin-reports/MRC-SOB-report-2010full-report.pdf
Peterson, B., and C. Middleton. 2010. Feeding Southeast Asia: Mekong River Fisheries and Regional Food Security.
Berkeley, California: International Rivers (IR).
http://www.internationalrivers.org/files/attached-files/intrivers_mekongfoodsecurity_jan10.pdf
Thompson, C. 2008. First Contact in the Grater Mekong. World Wildlife Fund (WWF) Greater Mekong Programme.
http://awsassets.panda.org/downloads/first_contact_final_report.pdf
Tone River Management Office of the Ministry of Land, Infrastructure, Transport, and Tourism, Kanto Regional Development Bureau.
What are the Unique Characteristics of Japan’s Rivers? (in Japanese).
http://www.ktr.mlit.go.jp/tonedamu/tonedamu00082.html (Last accessed on September 30, 2012)

Yuka Kiguchi

1. Through the remainder of this Briefing Paper (BP), simply “Burma” will be used.

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