Quantifying water-borne spreading of elements in the Lake Baikal

Report
Quantifying water-borne spreading of elements in the Lake Baikal Basin
Jerker Jarsjö, Josefin Thorslund and Jan Pietron
Dept. of Physical Geography and Quatenary Geology,
Stockholm University
e-mail: [email protected]
Ka
Stockholm University
Department of Physical Geography and Quaternary Geology:

One of the major departments within the Faculty of Science at Stockholm
University

Has approximately 120 employees and educates approximately 1500
students annually

Main research disciplines are Climatology, Ecological Geography,
Geographical Data Processing, Geomorphology, Glaciology, Hydrology,
Remote Sensing, Tropical Geography, and Quaternary Geology,

Education is oriented towards geography and geosciences, including
hydrology and environmental protection.
Hydrology group:
1 professor (hydrology, hydrogeology and water resources),
3 assistant professors, 5 post-docs/researchers, 16 PhD students
Collaboration
• Field campaigns, joint modeling and analysis work:
Moscow State University, Faculty of Geography, Dep. Hydrology,
Mongolian Academy of Sciences, Geography Institute
Methods
•
•
•
Laboratory and field measurements of
hydroclimatic, geochemical and
geomorphological parameters
Statistical analyses of hydro(geo)logical
and environmental data
Development of basin-scale, predictive
hydrological models:
-distributed (GIS-based) modelling
-sediment transport models (HEC-RAS)
Background:
Permafrost area, ultimately drains into the Arctic Sea
Essentially unregulated
Unique ecosystems in Lake Baikal and the Selenga River
delta
Pollution and sediment transport in the Selenga river Basin
-Heavy metals from mining
-Nutrients from agriculture
Russia
Objectives
Confront multi-method field investigations in Baikal Basin
with multi-model quantification approaches
to investigate fundamental research questions
on the transport of substances through large drainage
basins and impacts of human activities.
From source to recipient:
Example flowpaths and transport times
River basin
Stream
network
Surface water
divide
Contaminant
Slow flow through
Source 2
Contaminant groundwater
Source 1
Fast flow
through stream
Coastline
Streamflow into the sea
Diffuse SGD into the sea
Coastal water
How much will contaminant sources 1 & 2 contribute
to coastal pollution…
… if degradation occurs at the same rate in both cases?
Mass delivery fraction:
Mass delivery fraction:
The fraction of mass released at
a location that reaches the
recipient...
...for a given flow field and
degradation rate, l.
Method: Destouni, G., Persson, K., Prieto, C. and Jarsjö, J., 2010. General quantification of catchment-scale nutrient and pollutant
transport through the subsurface to surface and coastal waters. Environmental Science & Technology, 44(6), 2048–2055
Application: Khadka, S., 2010. Catchment-scale transport through groundwater to surface waters of the Lake Baikal drainage basin, MSc
thesis, Stockholm Univ.
Heavy metals spread in dissolved form and
with sediments
 Estimate total mass flows
– and its variance –
along the river network
(+erosion,deposition/accumulation)
Heavy metal loads
(Zaamar):
Tuul – Orkhon - Selenga
Measurement
locations
for C and Q
Zaamar Goldfields:
Placer mining along
Tuul river
’Placer mining’ – alluvial sediments (river bank)
Increases sediment and pollutant transport
Estimated mass flows of heavy metals
From: Thorslund, J., Jarsjö, J., Chalov, S.R., and Belozerova, E.V., 2012. Gold mining impact on riverine heavy metal transport in a
sparsely monitored region: the upper Lake Baikal Basin case. Journal of Environmental Monitoring, 14, 2780–2792
Main findings
• Mining increases natural transport of dissolved heavy metals by an order
of magnitude.
•
Transport in suspended phase much higher than the dissolved one
• The suspended phase transport increased by 1-2 orders of magnitude
during a single rainfall event  Mass flows may be underestimated if
sampling is infrequent
• Hypothesis: High pollution transport in suspension and lower downstream
pH can contribute downstream dissolution, explaining why dissolved
concentrations are higher farther away from the mining site than on it
• Critical question: How long distances can sediments from the mining site be
transported?
Modelled sediment
discharge
Increased sediment
discharge where channel
slopes are steep (as in the
Zaamar Goldfield)
16Sep2011 00:00:00
Tuul-Mai n
8000
Legend
16SEP2011 00:00:00-Sediment Discharge (tons/day)
Sediment Discharge (tons/day)
Sediment discharge (tons/day)
7000
6000
5000
4000
3000
2000
1000
0
0
50
Distance along river (km)
100
150
Main Channel Distance (km)
200
After: Pietron, J., 2012. Modeling sediment transport in
the downstream Tuul River, Mongolia, MSc thesis NKA
61, Stockholm Univ.
250
Modelled sediment
discharge
Sediment deposition (fine
particles) just downstream
of the Zaamar Goldfield
16Sep2011 00:00:00
Tuul-Mai n
8000
Legend
16SEP2011 00:00:00-Sediment Discharge (tons/day)
Sediment Discharge (tons/day)
Sediment discharge (tons/day)
7000
6000
5000
4000
3000
2000
1000
0
0
50
Distance along river (km)
100
150
Main Channel Distance (km)
200
After: Pietron, J., 2012. Modeling sediment transport in
the downstream Tuul River, Mongolia, MSc thesis NKA
61, Stockholm Univ.
250
Main findings
• Under normal hydrologic conditions, most of the material released by
mines is deposited within the first kilometres downstream of the mining
area
• During peak flow events, the contaminated sediment may be transported
further downstream the reach. Consequently, the mining waste sediment
can contribute to sediment loads leaving the Tuul River system.
• Higlights the importance of extreme events on overall transport
Future work, plans and possibilities
• Local transport processes: hydrochemical conditions in different connected
water systems: waste ponds, groundwater, channels, river water, suspended
material, river sediments
• Phase transformation processes: equilibrium and/or non-equilibrium
• Presense of geochemical gradients on different scales (local-regional)?
• Implications of local processes for large-scale transport?
• Projected future chages: Impact of land use change, water use change and
climate change (e.g., methods from parallel work in the Aral Sea basin):
average conditions, peak flows, contaminant transport
Publications
Internat.
Journal
papers
(Selenga
-Baikal)
MSc
theses
(Selenga
-Baikal)
Internat.
Journal
papers
(Analysis
methods)
Chalov SR, Zavadsky AS, Belozerova EV, Bulacheva MP, Jarsjö J, Thorslund J, Yamkhin J.,
2012. Suspended and dissolved matter fluxes in the upper Selenga river basin.
Geography Environment Sustainability 5(2): 78-94
Thorslund J, Jarsjö J, Chalov SR, Belozerova EV, 2012. Gold mining impact on riverine
heavy metal transport in a sparsely monitored region: the upper Lake Baikal Basin case.
Journal of Environmental Monitoring, doi: 10.1039/c2em30643c
Pietron, J., 2012. Modeling sediment transport in the downstream Tuul River, Mongolia,
MSc thesis NKA 61, Stockholm Univ
Khadka, S., 2010. Catchment-scale transport through groundwater to surface waters of
the Lake Baikal drainage basin, MSc thesis, Stockholm Univ.
Jarsjö, J., Asokan, S.M., Prieto, C., Bring, A. and Destouni, G., 2012. Hydrological
responses to climate change conditioned by historic alterations of land-use and wateruse. Hydrology and Earth System Sciences, 16, 1335–1347.
Destouni, G., Persson, K., Prieto, C. and Jarsjö, J., 2010. General quantification of
catchment-scale nutrient and pollutant transport through the subsurface to surface and
coastal waters. Environmental Science & Technology, 44(6), 2048–2055

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