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EFFECTS OF UPSTREAM HYDROPOWER DAMS AND WATER DIVERSION PROJECTS
TO THE DROUGHT AND SALINE INTRUSION OF THE MEKONG RIVER DELTA IN VIETNAM
Le Anh TuanCan Tho Univerity
E‐mail: [email protected]
The Mekong River Delta (MD), the most downstream region of the Mekong River.
The MD is receiving more than 85% of water volumes from the mainstream of the Mekong River before running out to both the Sea and the Gulf of Thailand.
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Mil. Ton
(2013)24.850.000 ton
The Delta supplies more than 53% of the nation’s staple rice and crop food, 80%of the total fish production, and 75% of fruits for domestic and export.
FLOOD
DROUGHT
HEAT WAVES
HIGHSOLAR RADIATION
SEA LEVEL RISE
SEA LEVELRISE
SALINE INTRUSION
SALINE INTRUSION
ABNORMAL RAINFALL
WHIRLWIND& STORM
LAND SUBSIDENCE
COATAL LINES EROSION
RIVER BANKSEROSION
ChinaMyanmar
Thái Lan
Laos
Cambodia
Vietnam
China
Cambodia
Peak flow to Tan Chau Station in last 90 years, the lowest is in 2015
In 2015‐2016, the Mekong Delta is facing the worst drought and saline intrusion in recent history.
Tân Châu
2015
The El Nino phenomenon and the water storage of reservoirs’ hydropower dams on the upper streams of the Mekong river are considered as the main reasons of this serious drought.
Peak floods trend-lines to Delta via Tan Chau and
Chau Doc were decreasing
Water Level in DAI NGAI
Station
Low upstream flow leads the salinity intrusion to coastal areas more serious, special in year 2016
In the winter‐spring crop 2015‐2016, more than 339,000 hectares of rice in coastal Mekong Delta provinces are prone to saltwater intrusion and drought, accounting for 35.5% of those localities’ rice areas and 21.9% percent of the region’s total rice area. Of these, 104,000 ha have been severely impacted.
There were 10/13 provinces in the MD have announced their drought disaster situation
As a draft estimation, the MD has lost about 200.000 ton of rice, resulting in a loss of over $44.64 million due to the drought in 2016.
LONG AN (23/2)
TIỀN GIANG(05/2)
BẾN TRE(05/2)
TRÀ VINH(09/3)
SÓC TRĂNG(23/2)
CÀ MAU(29/2)
KIÊN GIANG(19/2)
VĨNH LONG(09/3)
BẠC LIÊU(1/4)
HẬU GIANG(22/4)
HYDROPOWER DEVELOPMENT
The operations of the dam‐reservoir‐hydropower systems may create adverse effects for environmental flows, agricultural production and wetland ecosystems.
Hydropower dam development plans in main and tributary streams seem a priority alternative in the Upper River countries for serving energy and water demands highly.
Chinese ministry spokesman Lu Kang said that China has decided to open the sluice gates of the Jinghong Hydropower Station from March 15 to April 10 to release water downstream as a reply partly of Vietnamese Gov.’s request. The water discharge is 2.190m³/s, he informed.
Height 108 m Length 704.5 mActive Storage 249 mil. m3
Installed capacity 1,750 MW
Notice:
• Total water amount released from Jinghon Reservoir to Chiang Sean since 01Jan. 2016 –22Mar2016 was lower than in 2014 and 2015 in the same period.
• Chinese has release water for their electricity needs mainly instead of for LMB countries domestic and agricultural use.
• Water released from Jinghon can not push/prevent saline intrusion in the MD.
Project Kong – Loei – Chi ‐Mun aims to divert water for Thailand’s use by dredging the Loei River 5m deeper and spreading Loei estuaries a further 250 m wide.
In addition, around 24 tunnels will be constructed at the bottom of the LoeiRiver so there will more water from the Mekong River flowing into the Loei River, then to the Chi and Mun rivers.
The aim is to help irrigating 113 districts of 17 northeastern provinces in Thailand for the dry season.
www.mekongeye.com
Source: http://www.southeast‐asia‐sea.org/southeast‐asia‐sea/hanhan17.jpg
WATER DIVERSION PROJECTS IN THE NORTHEAST OF THAILAND: PAKCHOM ‐ UBOLRAT
Khong‐Loei‐Chi‐Mun Project will increasing irrigated areas up to 1.800.000 ha in the wet seasons and 900.000 ha in the dry season.
It needs a flow discharge 1.200 m3/sec
The MD Ave. Discharge in the dry season is 2.500 m3/s.
This mega‐project will take nearly a half of the total discharge of the river.
Q # 2.500 m3/s
MEKONG RIVER IN THE DRY SEASON
THAILANDKhong‐Loei‐Chi‐Mun Project
1.200 m3/sLAOS
North Vientaine 20.000 ha Project240 m3/s
CAMBODIAVAICO 100.000 ha Project
500 m3/s
VIETNAM??? m3/s
IRRIGATION PROJECTS
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6 POTENTIAL RISKS TO THE COUNTRY’S
ENVIRONMENT
CLIMATE CHANGE & SEA LEVEL RISE
UPSTREAM HYDROPOWERDEVELOPMENT & WATER DIVERSION
OVER‐EXPLOITING NATURAL RESEOURCES
SOIL – WATER AND AIRDEGRADATION
INCREASING POPULATION
AND MIGRATION
CHANGING THE LAND USE
Lower flows to the Mekong River did not only provide necessary freshwater and alluvium the Delta’s ecosystem and agricultural production, but also let higher sea tides bringing more saline intrusion up 50 to 80 km into cultivated inland.
If these hydrologic variabilities combined with other human water extraction and hydropower dam development factors, the MD’s water challenges may become worsen in the future.
For a long term strategy for water security in the MD, there is an urgent need for an inclusive and stakeholders participatory approach in the water resource planning and management. Carefulness is necessary in every phase of water project development with regard to social and environmental outcomes.
The Lower Mekong River Regions have more serious threats or double impacts –climate change and upstream dams - as a consequence. In combination, projected climate, industrial development, and upstream dams operation could increase many negative effects on local rice and fish cultivation in the Delta.
