Abstract:
The hydrochemical study of meltwater draining from a catchment dominated by snowmelt in a
cold-arid trans-Himalayan region of Ladakh, India, was carried out for an entire melting season
(May–September) during the year of 2010. Cation concentration in the meltwater shows a consistent
trend of Ca>>Mg>Na>K for this period. Carbonate weathering has been identified as the
dominant process controlling the dissolved ion chemistry of meltwater in the study area. There are
indications that atmospheric aerosols contain alkaline dust, sea salt and anthropogenic aerosols like
NO3 and SO4 that might have also added some solute to the system. Meltwater chemistry has been
showing an intra-annual variation with highest concentration for most of the dissolved solutes during
the late melt period, pointing towards the contribution of ground ice melt to the catchment runoff.
The lowest concentration during the peak melt period is due to higher contribution from snow melt
which has less residence time to interact with rock. Cationic denudation rate for this catchment has
been estimated as 778 meq m 2 a 1, while the average total dissolved solids flux for early, peak and
late melt period is 0.64 t day 1, 3.02 t day 1, 1.31 t day 1, respectively.
