Long-term modelling of runoff formation processes at remote
mountainous permafrost basin using historical data of short-term special
observations (Suntar-Khayata Ridge, Eastern Siberia)
Abstract. The study investigates the possibility to
parameterize a hydrological model for remote high-altitude permafrost
basin based on the data of historical short-term observations conducted
in 1957-1959 at the Suntar-Khayata research station (Eastern Siberia)
and simulate the changes of runoff observed in recent decades in the
region. The Hydrograph model is applied as it has the advantage of using
observed physical properties of landscapes as its parameters. The
developed parametrization of the goltsy landscape is verified by the
results of simulations of variable states of snow and frozen ground.
Continuous simulations of streamflow with daily time step are conducted
for the period of 1957-2012 at the Suntar River basin (area 7680
km2, altitude 828-2794 m) with average and median
values of Nash-Sutcliff criteria reaching 0.58 and 0.67 respectively.
The results of simulations have shown that the largest part of runoff
(about 70%) is formed in the high-altitude area which takes only 44%
of the Suntar River basin area. Simulated series of streamflow reproduce
the patterns of recently observed changes, including the increase of low
flow, by magnitude of trends and their change period, suggesting that
the increase of the increase of liquid precipitation share in autumn
months due to air temperature rise can be important factor of streamflow
changes in the region. The data presented in the paper are unique for
the vast mountainous parts of North-Eastern Eurasia which play important
role in general climate circulation. The results indicate that if the
assessment of hydrological model parameters is based on observation data
instead of calibration, the models can be used in the tasks of studying
the response of river basins to climate change with more confidence.
Keywords: remote high-altitude permafrost basin, hydrological
model Hydrograph, short-term observations, parametrization, goltsy,
climate change, Suntar River, streamflow, state variables