TITLE:
Controls on Gosaikunda Lake Chemistry within Langtang National Park in High Himalaya, Nepal
AUTHORS:
Maya P. Bhatt, Seema Bhatt, Birgit Gaye
KEYWORDS:
Gosaikunda, High Himalaya, Langtang, Geochemical Processes, Nutrients
JOURNAL NAME:
International Journal of Geosciences,
Vol.5 No.10,
September
26,
2014
ABSTRACT: Surface
water samples and lake bed sediments were collected and analyzed from
Gosaikunda Lake within Langtang National Park (28°05'N, 85°25'E; 4380 m a.s.l.)
in the central Himalayan region of Nepal during fall 2011. The major cations
and anions in equivalents were present in the following order:
and
, respectively. Sulfide oxidation coupled with carbonate
dissolution and aluminosilicate dissolution appeared to be the dominant
geochemical processes determining lake water dissolved ions. Sulfate
concentration was much higher than the alkalinity which is in contrast to
glacier meltwater within the same landscape. Alkalinity primarily as
bicarbonate contributes 88.6% to the total dissolved inorganic carbon (DIC)
followed by carbon dioxide (CO2) and carbonate (CO3) in
surface water samples. Organic carbon contributes 0.3% to 5.4% to the sediments
and the organic matter is predominantly of aquatic origin. The lake is under
saturated with carbon dioxide and the average partial pressure of carbon
dioxide (pCO2) appeared quite low (43.4 μatm). Overall, natural
biogeochemical processes regulate the chemical species within the lake
ecosystem. The lake is oligotrophic, however, nutrients and dissolved organic
carbon (DOC) concentrations are enhanced at the near shore sites close to the
tracking trail.