water quality of the yarlung tsangpo (brahmaputra) huang xiang and mika sillanpää november 19th,...
TRANSCRIPT
Water Quality of the Yarlung Tsangpo
(Brahmaputra)
Huang Xiang and Mika Sillanpää
November 19th, 2011, New Delhi
International conference of ”River Waters: Perspectives and Challengies for Asia”
Huang HeYangtze River
Mekong River
Salween River
Irrawaddy
Yarlung Tsangpo
Ganges
Indus
Water Tower of Asia
Yangtze River
The longest river in Asia and the third longest in the world (6 300 km, 509 km in Tibet)It drains in total nearly 1/5 of China (1.8 million km2, 23 060 km2 in Tibet)
The seventh longest river in Asia and the 12th longest in the world (4 500 km, 509 km in Tibet)It drains in total 810 000 km2 (38 300 km2 in Tibet)
Mekong River
The second longest river in Southeast Asia (3 200 km, 1 393 km in Tibet)It drains in total 325 000 km2 (102 500 km2 in Tibet)
Salween
Yarlung Tsangpo
The largest river on the Plateau Known as Brahmaputra downstream in India, it becomes the fifth largest river in the world (3 350 km, 2 057 km in Tibet) It drains in total 630 000 km2 (240 480 km2 in Tibet)
Objectives
- To assess temporal and spatial variations of chemical
composition of the Yarlung Tsangpo
- To address possible mechanisms governing the spatial
variation of the water chemistry
- To identify potential sources of contamination
Sampling preparations
Total of 35 quality parameters were under
taken in consideration:• Water temperature, pH, electrical conductivity (EC)
and turbidity
• Major ions (Ca2+, Na+, K+, Mg2+, Cl-, NO3-, HCO3
-, SO4
2-, NH4+, PO4
3- and F-)
• Trace elements (Al, As, Ag, Cu, Fe, Li, Mn, Mo, Ti, Zn, Cd, Co, Cr, Ni, Pb and Hg)
• Total dissolved sulphur (S), -phosphorus (TDP), - nitrogen (TDN) and -silica (SiO2)
Data interpretation - TDS in the Tibetan waters
0
50
100
150
200
250
300
350
Salween River
Mekong River
Yangtze River
Yarlung Tsangpo
Europe *Asia *
Africa *
North Americ
a *
South America *
World *
* Calculated according to Wetzel, 1975
TDS
(mg/L)
Water chemistry of the Tibetan rivers
0
10
20
30
40
50
60
70
80
90
100
mg/
L (
EC
in m
S/m
) Tibetan Plateau
World
Mg2+Ca2+ Na+ K+ NO3- HCO3
- SiO2SO42- Cl- EC
Data interpretation- Major ion composition
Ca2+ Mg
2+0 20 40 60 80 100
Na+ + K+
0
20
40
60
80
1000
20
40
60
80
100
Contributors of Salween River Salween River main streamContributors of Mekong RiverMekong River main stream Contributors of Yangtze RiverYangtze River main streamContributors of Yarlung Tsangpo Yarlung Tsangpo main stream
0 20 40 60 80 1000
20
40
60
80
100
SO42-
0
20
40
60
80
100
HCO3-
Cl-
Source: Huang X. Water Quality in the Tibetan Plateau: Chemical Evaluation of the Headwaters of Four Major Asian rivers”, dissertation, University of Eastern Finland, Finland, 2010.
UNIVERSITY OF EASTERN FINLAND LAEC
No systematic water quality assessment over the Plateau!
Current state
As (246 µg/L)
Mining in Gyama
Four mines existed
during the field work,
but more mines are
under constructionOnly sedimentation
ponds to treat effluentsGyama stream drains
into the Lhasa river,
which is a tributary to
Yarlung Tsangpo
Data interpretation - Major controlling factor in Yarlung
Tsangpo
0,40,30,20,10,0-0,1-0,2
0,4
0,3
0,2
0,1
0,0
-0,1
-0,2
-0,3
PC 1 (37%)
Li
Ti
Mo
S
MnFe As
AlTDS
SiO2
SO4
NO3
Cl
HCO3
K
Na
Mg
Ca
Turbidity
EC
pH
Temp.
PC
2 (
17%
)
Factors affecting water qualityof Tibetan rivers
Natural processes Mining activities Municipal wastesClimate change