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Lappeenranta University of Technology, Laboratory of Green Chemistry
Project Title:
Impact of Climate Change on Water Quality: A Himalayan Case Study
By Yulan Zhang, Mika Sillanpää
Background Information
The Tibetan Plateau is called the “Water Tower of Asia” as it is the source of the eight largest
rivers in Asia. The impacts of climate change on glacier status will affect the Asian water tower.
Especially across Himalayan regions, the glaciers are the headwaters of many prominent Asian, and
experiencing intensive shrinkage characterized by the great reduction in glacial length and area and
the most negative mass balance [Anthwal et al., 2006; Bolch et al., 2012; Immerzeel et al., 2010; T
Yao et al., 2012]. These changes have raised a great concern during the last decades due to their
water supplies for around 1.4 billion people in Asia [Immerzeel et al., 2010], as well as contributions
to sea level [Jacob et al., 2012], and other potential influences (e.g. geo-hazards) of glacial melting in
the downstream region.
During the last several years, river water samples were collected from the Yarlung Tsangbo,
Indus, Ganges, Yangtze, Mekong, and Salween rivers in order to study the water quality (Fig. 1). We
measured the water quality parameters (pH, EC, TDS, water temperature) by using Wagtech CP1000
at the sampling sites and analyzed the element concentrations by using ICP-AES. The results show
that all the rivers have an alkaline environment. For Yarlung Tsangbo river, TDS has a positive
relationship with Ca and Mg concentrations (Fig. 2), and the elemental contents are comparable
among the samples from Indus and Gangas river basins (Fig. 3) [Zhang et al., 2013]. In a few
locations, the results show relatively high concentrations of Al and Fe, while the concentrations of Cu,
Zn, Ag, Cd and Cr were generally low [Huang et al., 2008]. For the Tibetan rivers, Ca2+ and HCO3were the dominant ions with the exception of Yangtze river enriched in Na+, Cl- and SO42- due to
silicate weathering [Huang et al., 2009a, 2009b] (Fig. 4). The river water quality in this region is under
the influence of climate change on the glacier melting, which will change the seasonal discharge of
river runoff.
For this project, Himalayan partner research institutes include Laboratory of Green Chemistry
(Lappeenranta University of Technology, Finland), Institute of Tibetan Plateau Research (Chinese
Academy of Sciences, China), and Kathmandu University (Nepal). The earlier researches have
created a solid foundation and experience to carry out the proposed research and helped to identify
most relevant research areas.
Fig. 2 The concentrations of Ca
and Mg versus the TSD in the
river water samples across the
Himalayan region.
Yangtze river
Fig. 3 The average concentration
of elements from Yarlung Tsangbo,
Indus and Ganges river waters.
Fig. 1 The location map of focal study areas over the Tibetan Plateau, including the Brahmaputra,
Indus and Ganges river source regions, the Qiangyong, Nam Co (Tibet) and Phewa (Nepal) lakes,
and the Lhasa River monitoring station.
Aims
In this work, impact of climate change on water quality of the headwaters of three major Asian
rivers, i.e. the Brahmaputra River, Indus River and the Ganges River draining the Tibetan Plateau
and the lake sediments from respective watershed areas will be disclosed and evaluated. Thus the
impact of global change and major factors controlling the chemistry of these waters, habitat and
ecology of climate change sensitive aquatic organisms (fish and macroinvertebrates) will be
identified. The focus will be on rivers, their tributaries and lakes in both of Tibet and Nepal side,
which we have not covered in our earlier research. Also, possible mechanisms governing the
seasonal and spatial variation of the water chemical compositions in these water bodies will be
investigated. Importantly, online monitoring stations, being able to detect sudden changes, such as
mining effluent leakages and spillovers, will be implemented. Further, the data collected will be
utilised in the analysis of system-level transition towards sustainable water use in the region. The
overall objective of this work is to contribute to defining the present chemical quality of surface
freshwaters, and to increase the knowledge about detrimental environmental degradation and its
human impacts caused by the rapid economic development on the abundant freshwater under the
global warming.
Field Work Plan
The field work for this research will be conducted in full consultation with the local people and
local institute/university in the study area (China and Nepal). The researchers and assistants from
the local collaborators will participate during the sampling as much as possible. The familiar study
areas and assistance from local people will further enhance the chances of smooth completion of the
project work. River water samples from Yangtze river, Yarlung Tsangbo, Gangas, Indus and their
tributaries in the source regions were collected. In-situ measurements of water quality parameters
included the pH, electrical conductivity, water temperature, TDS, turbidity and chlorine by using
Wagtech CP1000 Portable Physico-Chemical Testing Laboratory. The information of latitudelongitude and elevation is determined by GPS to identify the sampling-site location. In this year, we
will continue to practice the field work plan in both of Tibet and Nepal sides. River and lake water,
and lake sediments will be collected for analysis of major ions, elements, and mercury to evaluate
the impact of climate change on the water quality.
Yarlung Tsangbo
Karnali River
Basin
Tibetan Plateau
Gandaki River
Basin
Koshi River
Basin
Fig. 4 Ternary plots of major cations (a) and anions (b) on an equivalent (meq L-1) basis for water
samples from Yarlung Tsangpo and its tributaries