Parameterizing a hydrological model using a short-term
observational data set to study runoff generation processes and
reproduce recent trends in streamflow at a remote mountainous permafrost
basin
Abstract. Recent decades have seen a change in the runoff
characteristics of the Suntar River in Eastern Siberia. This study
attempts to attribute these changed hydrological conditions through
parameterizing a hydrological model based on historical short-term
observations conducted in 1957-1959 at the Suntar-Khayata research
station. 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 (rocky-talus) is
verified by comparison of the results of simulations of variable states
of snow and frozen ground with observations carried out in 1957-1959.
Continuous simulations of streamflow on a daily time step are conducted
for the period 1957-2012 in the Suntar River (area 7680
km2, altitude 828-2794 m) with mean and median values
of Nash-Sutcliff criteria reaching 0.58 and 0.67 respectively. The
results of simulations have shown that the largest component of runoff
(about 70%) is produced in the high-altitude area which comprises only
44% of the Suntar River basin area. The simulated streamflow reproduces
the patterns of recently observed changes, including the increase in low
flows, suggesting that the increase in the proportion of liquid
precipitation in autumn due to air temperature rise is an important
factor in driving streamflow changes in the region. The data presented
are unique for the vast mountainous parts of North-Eastern Eurasia which
play an important role in global climate system. The results indicate
that parameterizing a hydrological model based on observations rather
than blind calibration allows the model to be used in studying the
response of river basins to climate change with greater confidence.
Keywords: remote high-altitude permafrost basin, Hydrograph
model, short-term observations, hydrological model parametrization,
goltsy, climate change, Suntar River